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blairgowrie
06-06-2010, 03:10 PM
Continued from PART TWO: http://forums.ubi.com/eve/foru...641066668#3641066668 (http://forums.ubi.com/eve/forums/a/tpc/f/23110283/m/8061010468?r=3641066668#3641066668)

blairgowrie
06-06-2010, 03:10 PM
Continued from PART TWO: http://forums.ubi.com/eve/foru...641066668#3641066668 (http://forums.ubi.com/eve/forums/a/tpc/f/23110283/m/8061010468?r=3641066668#3641066668)

Xiolablu3
06-06-2010, 03:28 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by JTD:

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by irR4tiOn4L:

Ok, i see what you are saying. It could just have been an uber plane in reality too, and we have the poor fortune of having to fight it day in, day out (every newbie and his dog pick the Spit after all) </div></BLOCKQUOTE>

I'd say that the type of combat there was in real life is considerably different from what we do in game. The strong points of the Spitfire design weren't as important in real life as they are with us.
</div></BLOCKQUOTE>

it all depends on the situation. IMHO there where certainly times when the Spitfires advantages were extremely useful and absolutely critical to the victory....

The fast climb and turning ability of the Spitfire was incredibly important in the vicious air battles over Malta.

Col. Reade Tilley (link below) was adamant that , had Malta been defended by P47 Thunderbolts, then its defenders would have been annilated.

http://www.military-art.com/ma...files.php?SigID=1165 (http://www.military-art.com/mall/profiles.php?SigID=1165)

Tilley wrote a very important WW2 paper which was circulated through the RAF and USAAF titled 'Hints on Hun Hunting'

M_Gunz
06-06-2010, 04:32 PM
JtD, should a zoom end when you could run sustained climb a better better rate?
And if one plane ends zoom before the other, shouldn't that either end the test or at least let it climb on at sustained rate?

You should ask yourself what the factors are, what is tested besides zoom. I see conditions favoring either plane changing
throughout the test and the end of the test dragged out perhaps to balance against the start advantage of the FW. I don't
see something I can use to judge zoom in combat situations.

Gaston444
06-06-2010, 04:33 PM
You don't always need to get away from a Spitfire...:

http://img30.imageshack.us/img.../jjohnsononfw190.jpg (http://img30.imageshack.us/img30/4716/jjohnsononfw190.jpg)

I'd be really curious by the way of seeing a Me-109G achieve the same thing... Fat chance... Just like finding a foreign tactical evaluation that describes the Me-109/FW-190A interaction as follows: BnZs FW-190As and TURN-fighting Me-109 (the opposite does exist...:
http://luthier.stormloader.com/SFTacticsIII.htm )

A quote, I love this too much...: "FW-190 will fly at 1,500-2,500 meters and Me-109G at 3,500-4,000 meters. They interact in the following manner:



FW-190 will attempt to close with our fighters hoping to get behind them and attack suddenly. If that maneuver is unsuccessful they will even attack head-on relying on their superb firepower. This will also break up our battle formations to allow Me-109Gs to attack our fighters as well. Me-109G will usually perform boom-n-zoom attacks using superior airspeed after their dive.



FW-190 will commit to the fight even if our battle formation is not broken, preferring left turning fights. There has been cases of such turning fights lasting quite a long time, with multiple planes from both sides involved in each engagement."

Obviously the Spifire, with its effective high speed elevators, is far more suited to BnZ than the FW-190A... With the Spitfire's superior climb rate, much better high speed turn rate and better high speed vertical pitch response, it is obvious that trying to mix-it, in a Spitfire, in slow-speed horizontal turns with a FW-190A is a very ignorant move... As far as the actual reality is concerned... This is especially true when you consider the FW-190A's very mediocre real-life high-speed elevator performance gives such an opportunity to use high speed against it...

Gaston

na85
06-06-2010, 07:46 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Gaston444:
You don't always need to get away from a Spitfire...:

http://img30.imageshack.us/img.../jjohnsononfw190.jpg (http://img30.imageshack.us/img30/4716/jjohnsononfw190.jpg)

I'd be really curious by the way of seeing a Me-109G achieve the same thing... Fat chance... Just like finding a foreign tactical evaluation that describes the Me-109/FW-190A interaction as follows: BnZs FW-190As and TURN-fighting Me-109 (the opposite does exist...:
http://luthier.stormloader.com/SFTacticsIII.htm )

A quote, I love this too much...: "FW-190 will fly at 1,500-2,500 meters and Me-109G at 3,500-4,000 meters. They interact in the following manner:



FW-190 will attempt to close with our fighters hoping to get behind them and attack suddenly. If that maneuver is unsuccessful they will even attack head-on relying on their superb firepower. This will also break up our battle formations to allow Me-109Gs to attack our fighters as well. Me-109G will usually perform boom-n-zoom attacks using superior airspeed after their dive.



FW-190 will commit to the fight even if our battle formation is not broken, preferring left turning fights. There has been cases of such turning fights lasting quite a long time, with multiple planes from both sides involved in each engagement."

Obviously the Spifire, with its effective high speed elevators, is far more suited to BnZ than the FW-190A... With the Spitfire's superior climb rate, much better high speed turn rate and better high speed vertical pitch response, it is obvious that trying to mix-it, in a Spitfire, in slow-speed horizontal turns with a FW-190A is a very ignorant move... As far as the actual reality is concerned... This is especially true when you consider the FW-190A's very mediocre real-life high-speed elevator performance gives such an opportunity to use high speed against it...

Gaston </div></BLOCKQUOTE>

Still going on with that argument, eh? Start your own thread, then. This one is supposed to be about evading a spitfire, not comparing Bf 109 to Fw 190.

Kettenhunde
06-06-2010, 08:31 PM
Grunch,

I took a look at your spreadsheet. We agree on everything except you have the Rectilinear equations wrong.

You have s = (V^2-V^2)/a^2 in Block A14.

Acceleration is not squared. The UNITS for acceleration are Feet Per Second Squared.

The formula should read:

s = (V^2-V^2)/(2*a)

http://spreadsheets.google.com...25sUVBRMVVqblE&hl=en (http://spreadsheets.google.com/ccc?key=0Avb3JMLg1IVUdGpKX1dBd2tyN3Z4c25sUVBRMVVqb lE&hl=en)

Let me know when you find that error.

TheGrunch
06-06-2010, 09:03 PM
Oops, you're right. It's just in the description, though, not the actual formula used. Must've had a slow moment.

Gaston444
06-06-2010, 09:55 PM
Quote, TheGrunch: "Still going on with that argument, eh? Start your own thread, then. This one is supposed to be about evading a spitfire, not comparing Bf 109 to Fw 190."

-Well it IS useful to point out that in real-life, the sustained low speed turn rate of the Spitfire was good but nothing really special, and that the FW-190A was at its best doing exactly that... So in reality you did NOT want to challenge the FW-190A doing slow-speed turns in a Spitfire that could do many other things far better than an Anton, Eric Brown notwithstanding...

The Spifire was far better at high speed turning, climbing and thus at boom and zooming than the FW-190A: Why would you want to use it in a way where it was comparativewly at its worst vs the FW-190A?

Anyone noticed that the FW-190A's "curious dogfighting" vertical style, as alledged by Eric Brown, never achieves ANYTHING when the FW-190A uses it against the Spitfire? Including the one example E. Brown describes as having happened to him... But also several others (mostly early) instances I have read where the FW-190A does indeed go for that style of fighting (likely a wrong theory that got perpetuated in Luftwaffe squadrons: In the Luftwaffe many pilots did think the way simulations go today(heavy=baaaad), to the head-banging (and recorded) dismay of those, war-surviving, pilots who understood that mere intuition and simplistic math does not translate into actual performance)...

My guess is that the "curious style of dogfighting" was simply an early or wrong tactic that was gradually found either to stink the stink of death, or to be useable only very briefly...

Even E. Brown's own description of the tactic leaves one dubious: "Must take care not to kill speed by "sinking"... "Tactical restriction" on low-level dives"... Meaning that, if you use this brilliant and "appropriate" tactic, you are more likely to hit the ground than your opponent... The Soviets described the very same issue as causing the FW-190A to "hang" (dropping nose-up 660 ft), creating "a perfect target"... Not too encouraging is it?...

This is exactly why the far more experienced (than E. Brown) ace Johnny Johnson chose to paint, with the hindsight of the whole war behind him, a very different picture of the FW-190A, with a very different effect...

If you want to pit the combat experience of E. Brown (0 kills), against the combat experience of the highest-scoring Western allied pilot (30+ kills), whose experience is it more reasonable to go for?

Just injecting a dose of reality here...

Gaston

Kettenhunde
06-06-2010, 10:07 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Oops, you're right. It's just in the description, though, not the actual formula used. Must've had a slow moment. </div></BLOCKQUOTE>


Ok

The top speed of the Spitfire is officially listed as 330 mph at sea level not the 336mph from the a couple of individual reports. The 336mph is achieved with gun ports sealed and radiator flaps closed.

The official speed is a mean average over a percentage range and not an outstanding example.

Can you see how the Spitfire ending up 200 feet above the Focke Wulf as Wurkeri's original claim is nonsense?

Take a look and see if you can spot the error too.

JtD
06-06-2010, 10:43 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Xiolablu3:

it all depends on the situation. IMHO there where certainly times when the Spitfires advantages were extremely useful and absolutely critical to the victory.... </div></BLOCKQUOTE>

Yes, certainly. The plane was very successful, and that was for a reason. However, it wasn't perceived as an unbeatable dogfighter, neither by its pilots nor the opponents, as it is in game.

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by M_Gunz
JtD, should a zoom end when you could run sustained climb a better better rate?
And if one plane ends zoom before the other, shouldn't that either end the test or at least let it climb on at sustained rate?

You should ask yourself what the factors are, what is tested besides zoom. I see conditions favoring either plane changing
throughout the test and the end of the test dragged out perhaps to balance against the start advantage of the FW. I don't
see something I can use to judge zoom in combat situations. </div></BLOCKQUOTE>

Well, I posted the chart and not just the final number to allow everyone to look at the situation throughout the zoom. For instance, you don't need to look at the end, you can say for you it's over in second 50. 190 still ahead in terms of energy height, and also far ahead of the Spitfire. The only problem would be that you disagree with how the zoom comparison is done - for instance, if you prefer a far steeper angle or a same angle approach or a same time between starting and stall speed approach.
It is, however, my firm belief that you can use any setup you want - the result will be the same. If both pilots fly their planes well, the Spitfire is going to close the gap, not necessarily close it completely, but it will always be getting smaller in any type of climb. That's because of the relative performance of the two contenders.
As far as usefulness for combat is concerned - it shows that in a situation like that the 190 will not gain the initiative through a zoom climb in a situation like that. It also shows, through the lateral separation, that you can do the zoom climb without getting into immediate danger. It also tells you that if you're in a Spitfire, you can use a zoomclimb under these conditions to get away from a 190. You just need to be sure you have sufficient initial lateral separation.
One could also alter parameters, for instance initial speed of the participants, to see at which point the maneuver starts to make sense - for instance, how fast does the 190 needs to go to safely reach an altitude from which it can dive down onto the Spitfire again.

JtD
06-06-2010, 11:12 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Kettenhunde:

The top speed of the Spitfire is officially listed as 330 mph at sea level not the 336mph from the a couple of individual reports. The 336mph is achieved with gun ports sealed and radiator flaps closed. </div></BLOCKQUOTE>

I'd like to see a list with 330 mph please and also all other official lists to be positively certain that 336 mph is not officially listed. Personally, I consider 335 mph the valid number. The normal conditions for a high speed Spitfire flight were gun ports sealed and radiator flaps closed, unless the guns had been used already.
I'm not aware that a Fw 190 A-8 in service condition would do 578 at sea level. That would need the removal of the ETC 501, fitting of wheel doors, both of which wasn't typical, and the sealing of various gaps plus polishing, which in field conditions was rare at best.
335 mph are much closer to the typical in service Spitfire performance than the 578 km/h are to the typical in service performance of the 190.
So if you think that 280 knots represent an in service Spitfire MkIX Merlin 66 best, you should also take about 15 knots off of the top speed you used for the 190.
The reason I don't do that is very simple: Both planes in game are modeled to their optimum condition, and that is 540 km/h for the Spit and 580 km/h for the A-8.

TheGrunch
06-06-2010, 11:31 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Kettenhunde:
The top speed of the Spitfire is officially listed as 330 mph at sea level not the 336mph from the a couple of individual reports. The 336mph is achieved with gun ports sealed and radiator flaps closed.
</div></BLOCKQUOTE>
This is not an unusual condition for a Spitfire since as far as I remember the radiator could be operated manually in earlier Mark IX aircraft and gun ports were taped over before every sortie.
Given that the 335mph figure appears in more than just the performance test, for example here (http://www.spitfireperformance.com/merlin66_18_25.jpg) and here (http://www.spitfireperformance.com/merlin66_18_25b.jpg) we can be fairly certain the figure was considered official.
We also (unfortunately) have little information as to the condition of the aircraft or possibility of minor drag-reducing measures in FW-190 tests, so this kind of nitpicking is a bit one-sided. Consider for example the fact that most of the aircraft we have data for are old Mk V conversions rather than new build Mark IXs.

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Kettenhunde:
Take a look and see if you can spot the error too. </div></BLOCKQUOTE>
I'll get back to you on that one when I'm more sober. http://forums.ubi.com/images/smilies/88.gif Nothing jumps out at me, and I've been sitting rearranging equations for a couple of minutes.

Xiolablu3
06-07-2010, 03:19 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Gaston444:
Quote, TheGrunch: "Still going on with that argument, eh? Start your own thread, then. This one is supposed to be about evading a spitfire, not comparing Bf 109 to Fw 190."

-Well it IS useful to point out that in real-life, the sustained low speed turn rate of the Spitfire was good but nothing really special, and that the FW-190A was at its best doing exactly that... So in reality you did NOT want to challenge the FW-190A doing slow-speed turns in a Spitfire that could do many other things far better than an Anton, Eric Brown notwithstanding...

The Spifire was far better at high speed turning, climbing and thus at boom and zooming than the FW-190A: Why would you want to use it in a way where it was comparativewly at its worst vs the FW-190A?

Anyone noticed that the FW-190A's "curious dogfighting" vertical style, as alledged by Eric Brown, never achieves ANYTHING when the FW-190A uses it against the Spitfire? Including the one example E. Brown describes as having happened to him... But also several others (mostly early) instances I have read where the FW-190A does indeed go for that style of fighting (likely a wrong theory that got perpetuated in Luftwaffe squadrons: In the Luftwaffe many pilots did think the way simulations go today(heavy=baaaad), to the head-banging (and recorded) dismay of those, war-surviving, pilots who understood that mere intuition and simplistic math does not translate into actual performance)...

My guess is that the "curious style of dogfighting" was simply an early or wrong tactic that was gradually found either to stink the stink of death, or to be useable only very briefly...

Even E. Brown's own description of the tactic leaves one dubious: "Must take care not to kill speed by "sinking"... "Tactical restriction" on low-level dives"... Meaning that, if you use this brilliant and "appropriate" tactic, you are more likely to hit the ground than your opponent... The Soviets described the very same issue as causing the FW-190A to "hang" (dropping nose-up 660 ft), creating "a perfect target"... Not too encouraging is it?...

This is exactly why the far more experienced (than E. Brown) ace Johnny Johnson chose to paint, with the hindsight of the whole war behind him, a very different picture of the FW-190A, with a very different effect...

If you want to pit the combat experience of E. Brown (0 kills), against the combat experience of the highest-scoring Western allied pilot (30+ kills), whose experience is it more reasonable to go for?

Just injecting a dose of reality here...

Gaston </div></BLOCKQUOTE>


How can you be any more wrong about everything?

Eric Brown = 2 kills

FW190 incredible high speed manouverability and roll rate.

Spitfire = Far better turning circle than FW190, particularly at lower/mid speeds.

Every single paper from the RAF at this time which talks about the Spitfire vs FW190 explains the Spitfire's far better turning circle. The Fw190 has a higher wing loading, is a similar type of design, has no slats or high lift devices and is also much heavier than the Spitfire. How COULD it have a smaller turning circle at lower speeds?

Kettenhunde
06-07-2010, 04:59 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">That would need the removal of the ETC 501, fitting of wheel doors, both of which wasn't typical, </div></BLOCKQUOTE>


That is not correct. The ETC 501 was easy to remove in about 15 minutes and the wheel doors attach in under 30 seconds.

In fact, Focke Wulf even made flexible doors that did not need to be removed or replaced.

The finish is also listed on the sheet as normal service finish.

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">gun ports were taped over </div></BLOCKQUOTE>

That completely changes the aircraft both in handling and performance.

That is not a compatible condition to another aircraft that is combat ready either.

Additionally, they don't tape up the ejection ports in combat and that was frequently done in RAE Spitfire testing.

Kettenhunde
06-07-2010, 05:03 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">As far as usefulness for combat is concerned - it shows that in a situation like that the 190 will not gain the initiative through a zoom climb in a situation like that. </div></BLOCKQUOTE>


You are drawing a conclusion based off one condition.

It would be like concluding there is not a velocity the Focke Wulf cannot out turn the Spitfire.

TheGrunch
06-07-2010, 09:21 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Kettenhunde:
Additionally, they don't tape up the ejection ports in combat and that was frequently done in RAE Spitfire testing. </div></BLOCKQUOTE>
But not in any of the Spitfire IX +18 tests on Mike Williams' site apart from MA.648 with the S.U. injection pump. Your 330mph figure seems to be based on the calculated +18lbs/sq.in. performance of the rather slow JL.165 aircraft used for comparing the +25 and +18 boost levels:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content"> Spitfire Trials at +25 boost (http://www.spitfireperformance.com/jl165.html)
4.42. The comparison of this estimated performance with that obtained on Spitfire F.Mk.IX BS.543 with Merlin 66, shows rather lower figures for JL.165, particularly in all-out level speed.
http://img.photobucket.com/albums/v218/TheGrunch/JL165vsBS543.png
</div></BLOCKQUOTE>
You can see in this report and the other one (http://www.spitfireperformance.com/jl165rr.html) (which shows the calculated sea level speed of 330mph at +18lbs/sq.in.) that JL.165 is calculated to be around 20mph(!) slower than BS.543 in max level speed at +18lbs/sq.in. both MS and FS gear, even when JL.165 had ejection chutes taped over and BS.543 did not.

It just goes to show how much variation there can be in a type's performance, especially those converted from earlier types. JL.165 does seem to have been a particularly bad lemon, though. No wonder it never went back to an operational squadron after being used for testing.

We also have a speed chart demonstrating the performance of the August '42 new-build Mark IX aircraft, BS.310 (http://www.spitfireperformance.com/ma648speed.gif) (get a ruler and you can see that the intercept would be at about half a grid square left of the origin, at about 335mph) while briefly fitted with the Merlin 66, but unfortunately, no information as to the aircraft's condition other than that it was flown with ejection ports unsealed in every other test it was used in (wish they'd been more consistent!). I'd love to see the full performance test for BS.310 with the Merlin 66 engine fitted.

Finally there's MA.648 (http://www.spitfireperformance.com/ma648.html) which managed 340mph max level speed at sea level with the Mk.II S.U. fuel injection pump and ports sealed.

Kettenhunde
06-07-2010, 09:44 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">30mph figure seems to be based on the calculated </div></BLOCKQUOTE>

No it is based on what the RAF says the average Merlin 66 +18 Spitfire Mk IX achieved.

http://www.spitfireperformance.com/jl165rr.html

In this report, only BS310 and JL165 are performing to standard, the other aircraft are have above standard FTH. JL165 is the only one we have good sea level data on too.

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content"> The mean full throttle heights for BS.310, JL.165 and BS.543 are 9,200 ft. in MS gear and 20,300 ft. in FS gear, but the engine of BS.543 has full throttle heights far above average. Even then, the full throttle heights of MA.648 with the injection pump are above average by 200 ft. in MS gear and 800 ft. in FS gear. The new type intake on MA.648 is expected to reduce the full throttle heights by a small amount, so these figures may be rather pessimistic. </div></BLOCKQUOTE>

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content"> Level speed performance of this aircraft is slightly above average. This is attributed chiefly to the increase in full throttle height due to the substitution of the S.U. pump for the normal carburettor. </div></BLOCKQUOTE>

http://www.spitfireperformance.com/ma648.html

330mph is average, 336mph and 340mph above average.

Remove the sealed ejection ports and gun tubes and the handling and performance is effected.

Kettenhunde
06-07-2010, 09:49 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">which shows the calculated sea level speed of 330mph </div></BLOCKQUOTE>


It is measured not calculated in so much as all airspeeds are really calculated. This one just starts with flight measurements and then is calculated based on those measurements while converted for atmospheric as well as aircraft/engine conditions. It is subject to accuracy errors at each step of the way.

In fact, I would trust a pure calculated speed over a measured one during this time period.

TheGrunch
06-07-2010, 09:54 AM
Yeah, sure. That's not going to take 10mph off its speed, though, is it? BS.543 is a standard aircraft, nice of you to omit the previous paragraph:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">It will seen that the above full throttle heights vary considerably. Differences in ram effect due to speed variations account to some extent for this; for instance if the speed of JL.165 were increased to that of MA.468 the full throttle height would be increased roughly 500 ft. The effect of difference in ram effect on the other aircraft would not exceed 150 feet. </div></BLOCKQUOTE>
Also, the speed increase provided by the S.U. pump still would not have indicated a speed of around 330mph for MA.648 according to the report:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Owing to large variations in the performance of the four aircraft tested it is not possible to obtain an accurate value for the improvement in performance but the above quoted figures for increase in full throttle height give an average increase of about 3 mph. around the full throttle height. </div></BLOCKQUOTE>
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">The only satisfactory way to obtain exact figures would be to repeat the tests with the normal carburettor substituted for the injection pump. When this was done on Spitfire VB W.3322 (Merln 46 S.U. Mark I injection pump), the increase in speed at full throttle was about 5 mph, and the improvement in full throttle height 1300 ft. The increase in full throttle height indicated by the present report therefore seems to be pessimistic. </div></BLOCKQUOTE>

TheGrunch
06-07-2010, 09:58 AM
More info about JL.165 from the report you just quoted:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content"> A further point of note is the full throttle height at + 18 lbs. of boost which is somewhat lower than has previously been obtained with Merlin 66 engines. A check of the air intake efficiency was taken during the tests, a minimum figure of 94% in level flight being shown at + 25 lbs. sq.inch boost pressure. It would seem therefore that the full throttle height of this engine is low. </div></BLOCKQUOTE>
Given it says that the level speed performance of MA.648 is "slightly" above average, and that I don't think that 10mph is a particularly small figure in performance testing, it would seem that BS.543 is the average aircraft we're comparing to, especially given the numerous comments about the low standard of performance of JL.165.

TheGrunch
06-07-2010, 10:12 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Kettenhunde:
JL165 is the only one we have good sea level data on too. </div></BLOCKQUOTE>
What's wrong with the data on BS.543 (http://www.spitfireperformance.com/bs543.html)?
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Spitfire LF & HF Mk IX Test:
http://img.photobucket.com/albums/v218/TheGrunch/BS543.png </div></BLOCKQUOTE>

Kettenhunde
06-07-2010, 10:22 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content"> nice of you to omit the previous paragraph: </div></BLOCKQUOTE>

Do not accuse me of bias again, please. I don't think you are biased and if we can't have a mature conversation we will have no conversation at all.

Interpret that paragraph, Grunch.

What your highlighted portion says:

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content"> Differences in ram effect due to speed variations account to some extent for this; for instance IF the speed of JL.165 were increased to that of MA.468 the full throttle height would be increased roughly 500 ft. </div></BLOCKQUOTE>

It says that in order to achieve that speed they would have to raise the FTH 500 ft on JL165.

It goes on to say that is not very likely and in fact plans for the engine include lowering the FTH with the new tropical intake that was standard on all Spitfire models.

They got rid of those early awful tropical filters and replaced them with a universal tropical filter that was standard on all Spitfires throughout the war. It looks like a normal intake but could duct intake air through a filter if it was required for dusty unimproved airstrips.

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content"> The new type intake on MA.648 is expected to reduce the full throttle heights by a small amount, </div></BLOCKQUOTE>

It was not included by me because it has no relevance beyond establishing the fact the FTH and level speed are linked to non-technical folks. I think most of you know that already.

I don't see the relevance here:

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content"> Owing to large variations in the performance of the four aircraft tested it is not possible to obtain an accurate value for the improvement in performance but the above quoted figures for increase in full throttle height give an average increase of about 3 mph. around the full throttle height. </div></BLOCKQUOTE>

The test is a wash, the RAE says so! It is spelled out in plain english. The variation in performance was too large and not typical. The RAE gives what they think is the cause of it.

The aircraft in that test they felt were typical are also plainly identified as JL165 and BS310.

They go on to say that replacing the SU pump with a normal carborator and redoing the test might give them better data to work with!

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">The only satisfactory way to obtain exact figures would be to repeat the tests with the normal carburettor substituted for the injection pump. </div></BLOCKQUOTE>

You understand?

It is not pick and choose a 5mph increase from an above average engine data and then add in speed results from one aircraft that is a different variant!

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content"> When this was done on Spitfire VB W.3322 (Merln 46 S.U. Mark I injection pump), the increase in speed at full throttle was about 5 mph, </div></BLOCKQUOTE>

http://www.spitfireperformance.com/ma648.html

Kettenhunde
06-07-2010, 10:28 AM
What is wrong with BS543? The RAE states its engine was performing above average.

You should already have an understanding of the link in FTH and level speed. Much of that is just density effects. Going from 7000ft to 8000 ft is going to increase your TAS by ~5mph just from density changes.

That is established in your quote about JL165's hypothetical FTH increase.

You know the one you accuse me of bias because I left it out?

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content"> The mean full throttle heights for BS.310, JL.165 and BS.543 are 9,200 ft. in MS gear and 20,300 ft. in FS gear, but the engine of BS.543 has full throttle heights far above average. </div></BLOCKQUOTE>

http://www.spitfireperformance.com/ma648.html

TheGrunch
06-07-2010, 10:37 AM
I'm not accusing you of bias, don't worry about that, I just thought it was interesting that you chose not to mention it...especially since the report implies the causal link is in the other direction.
Why is BS.543 considered above average in that test and JL.165 considered below average in another? Is it manufacturer bias, perhaps? The JL.165 test *was* performed by Rolls Royce.

As for your 'fundamental error', you may as well explain, I don't think I'm getting it, been a long time since I did high-school physics, it could just be that in the first zoom climb scenario you're facing a situation where the pilots are NOT reducing thrust to match drag. Since the TE equations reach the same conclusion as the rectilinear ones in your example, perhaps we can conclude that the result does not account for the reduction in drag. Other than that I have no idea.
Also, that sounds wrong even to me, since you equalise thrust and drag in the second example for that reason...but hey, you miss 100% of the shots you don't take. I'm still leaning toward the fact that you've ignored the time variable, but then JtD said that when he said that a static calculation is not adequate.

M_Gunz
06-07-2010, 11:51 AM
Summer! Time for eating cherries!

TheGrunch
06-07-2010, 12:05 PM
Anyway, cherry-picking or not (there are three fast enough cherries with low enough stall speeds to pick here, BS.310, BS.543 and MA.648) the fact remains that despite the cast-iron conclusion Kettenhunde presented, if we take the speed of a genuine Spitfire IX whose sea-level speeds are recorded by a flight-test (BS.543 et al) and apply it to the system of equations he presented earlier, the slower aircraft does indeed out-zoom the faster one. Which is exactly opposite to the truism that's been described.
Cue frustration. Hopefully he'll clear that up momentarily by posting what he forgot in the calculation. This discussion is rather the side-issue. Any argument there?

JtD
06-07-2010, 12:17 PM
TheGrunch, thanks for the effort but it's a waste. Because it's just a red herring. If the argument over the realistic top speeds is closed, then there'd be no excuse to not fix the calculation. So, this one got to be argued to death. Much easier to pick and misinterpret flight performance data from which there's a plethora around, much of it so poorly documented that you can make out of it what you want.

Edit: I see you know that, too. http://forums.ubi.com/groupee_common/emoticons/icon_biggrin.gif

Fact is that Spitfire BS.543 was tested in service condition at 336 mph at sea level. It also made 382 mph at 10500 feet. The official number from the aircraft data card is 384 mph at 10500 feet, with no sea level speed given. Draw your own conclusions.
Also fact is that Fw data sheets, for a Fw 190A-8 with ETC 501 mounted, wheel doors mounted, surface filled and polished, give 578 km/h. Except for the ones that lists 565 km/h under the same ideal conditions. Again, feel free to make up your own mind.
But to be honest, I'd be curious to see the data sheet that gives 578 for a 190 with a normal surface finish.

M_Gunz
06-07-2010, 01:30 PM
330/336 = 98.2% in a sim with chart-tolerance of +/- 5%.

Why not run IL2 tests at IL2 power and speed? Less than 2% "extra" should be acceptable. It was IRL.

JtD I was taught that one aspect of a good fighter pilot is to know where your advantages are and use them.

Advantages of the IL2 FW 190A-8 mainly lie in roll and higher speed and firepower. Half-time in your test the
FW has traveled farther on his path and is moving faster with a significant energy margin though less than he
started with. In the 30 degree zoom test, the FW gets the advantage *first*. Spit does not catch up on height
until *later*. If the FW pilot can present enough threat, the Spitfire pilot will take a different path as well.

Of course a Dora or a 109K-4 would be more appropriate to pit against the high end Spitfire.

K_Freddie
06-07-2010, 01:44 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Gaston444:
.. to the head-banging (and recorded) dismay of those, war-surviving, pilots who understood that mere intuition and simplistic math does not translate into actual performance)...
</div></BLOCKQUOTE>
Kinda what I've been saying all along... http://forums.ubi.com/groupee_common/emoticons/icon_wink.gif

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Gaston444:
.. against the combat experience of the highest-scoring Western allied pilot (30+ kills), </div></BLOCKQUOTE>
A slight correction to that total ! (http://en.wikipedia.org/wiki/Marmaduke_Pattle)

TheGrunch
06-07-2010, 01:45 PM
A real forgotten hero, Pat Pattle.

Kettenhunde
06-07-2010, 02:06 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">it could just be that in the first zoom climb scenario you're facing a situation where the pilots are NOT reducing thrust to match drag. </div></BLOCKQUOTE>


And what is the acceleration without thrust and does that acceleration value just disappear?

TheGrunch
06-07-2010, 02:10 PM
What, gravity and momentum? Or am I totally spouting **** now?

JtD
06-07-2010, 02:20 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by M_Gunz:

Advantages of the IL2 FW 190A-8 mainly lie in roll and higher speed and firepower. Half-time in your test the FW has traveled farther on his path and is moving faster with a significant energy margin though less than he started with. In the 30 degree zoom test, the FW gets the advantage *first*. Spit does not catch up on height until *later*. If the FW pilot can present enough threat, the Spitfire pilot will take a different path as well. </div></BLOCKQUOTE>

Well, the Spitfire catches up with the 190 in terms of energy altitude as soon as the zoom climb starts - during the pull up. Then there's a short moment of roughly parity, but then the power of the BMW drops off and the Spitfire gains. It's still in the high speed region. The 190 never gains anything, under the best conditions it can barely defend the advantage it has from the higher level top speed.

Please also note that the Spitfire I'm using is the 18 lb model, not the 25lb one. That one might be able to maintain a 30 climb at certain altitudes. http://forums.ubi.com/groupee_common/emoticons/icon_wink.gif

Kettenhunde
06-07-2010, 02:25 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">surface filled and polished </div></BLOCKQUOTE>


This means surface prepared and polished:

http://img294.imageshack.us/img294/6636/fw190a5finish.jpg (http://img294.imageshack.us/i/fw190a5finish.jpg/)

This means surface prepared and painted with aircraft paint. It is a normal service finish.

http://img101.imageshack.us/img101/7792/fw190a8finish.jpg (http://img101.imageshack.us/i/fw190a8finish.jpg/)

Please produce some data on the FW-190A8 were the machine is polished.

JtD
06-07-2010, 02:50 PM
Will do, right after you fix your calculation. Just trying to make sure you don't lose focus.

Glattanstrich btw. means smooth paint job. Usually goes with 565 km/h, but I know a table that lists 578. Not a data sheet, though.

TheGrunch
06-07-2010, 03:19 PM
I can't find one on the internets but that doesn't mean anything.
I'm going to insert a brief, calming photo interlude. http://forums.ubi.com/groupee_common/emoticons/icon_wink.gif

http://fw190.hobbyvista.com/wadman8.jpg
http://www.spitfiresite.com/photos/historic/uploaded_images/412-sqn-march-45-741598.jpg

thefruitbat
06-07-2010, 03:29 PM
mmmm,


http://aggie-horticulture.tamu.edu/syllabi/319/images/Bingcherry.jpg

M_Gunz
06-07-2010, 03:45 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by JtD:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by M_Gunz:

Advantages of the IL2 FW 190A-8 mainly lie in roll and higher speed and firepower. Half-time in your test the FW has traveled farther on his path and is moving faster with a significant energy margin though less than he started with. In the 30 degree zoom test, the FW gets the advantage *first*. Spit does not catch up on height until *later*. If the FW pilot can present enough threat, the Spitfire pilot will take a different path as well. </div></BLOCKQUOTE>

Well, the Spitfire catches up with the 190 in terms of energy altitude as soon as the zoom climb starts - during the pull up. </div></BLOCKQUOTE>

That is not what your own graph shows on this page. (http://forums.ubi.com/eve/forums/a/tpc/f/23110283/m/8061010468/p/18)

http://mitglied.lycos.de/jaytdee/testgraph/zoomclimb2.JPG

The Spitfire doesn't catch up on Eh until 30 seconds!

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Then there's a short moment of roughly parity, but then the power of the BMW drops off and the Spitfire gains. It's still in the high speed region. The 190 never gains anything, under the best conditions it can barely defend the advantage it has from the higher level top speed. </div></BLOCKQUOTE>

Perhaps you mean altitude alone which is something funny considering that the FW was forced to a lower angle in order
to force the two to gain altitude at the same rate. If so then what you describe are not findings so much as reporting
success of method.

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content"> Please also note that the Spitfire I'm using is the 18 lb model, not the 25lb one. That one might be able to maintain a 30 climb at certain altitudes. http://forums.ubi.com/groupee_common/emoticons/icon_wink.gif </div></BLOCKQUOTE>

Still you choose a lemon from the IL FWs bin. It makes any Spit IX look better.

JtD
06-07-2010, 04:05 PM
M_Gunz, I meant "catch up" as in getting closer, not as in being equal. Poor grammar on my side, I guess.

I didn't pick the planes, just went with what had been discussed at that point.

Kettenhunde
06-07-2010, 05:14 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Glattanstrich btw. means smooth paint job. </div></BLOCKQUOTE>


Which is the term for normal RLM paints.

It means the airframe was properly prepared:

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content"> Etch and Alodine Surface preparation for painting is the most important requirement for insuring proper adherence and performance of a paint system. </div></BLOCKQUOTE>

http://www.slideshare.net/ahef...-should-know-1204141 (http://www.slideshare.net/aheffernan/aircraft-painting-what-you-should-know-1204141)

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content"> A quality shop will take the time to hammer out and fill the small dents and then reprime the areas, leaving a smooth finish for the paint. </div></BLOCKQUOTE>

http://www.aopa.org/pilot/btn172/btn9412.html

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content"> The aircraft then receives a final cleaning to remove small particles and ensure a smooth finish. </div></BLOCKQUOTE>

http://www.bygeorgeaircraftpainting.com/services.html

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content"> An epoxy chromate primer is then applied and, depending on the aircraft, an epoxy surfacer is applied to assure a perfectly smooth surface on which the base coat of paint is applied. </div></BLOCKQUOTE>

http://www.aerosmithaviation.com/1_ExtPaint_1.html

With the exception of wing walk compound, aircraft paint is designed for a smooth finish.

Mind boggling concept isn't it?

Have you ever applied RLM paints or compared them to US wartime aircraft paints?

A polished finish is not the same as a normal aircraft paint job.

Kettenhunde
06-07-2010, 05:45 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content"> If so then what you describe are not findings so much as reporting success of method. </div></BLOCKQUOTE>

It is not about the truth, it is about proving me wrong, M_Gunz.

It is a simple fact, velocity is the most important factor in a zoom climb.

It is absolute fantasy for your games Spitfire to end up 200 feet above the Focke Wulf as per Wurkeri's original claim.

That is not how the physical world works.

It takes the most optimistic data available to equal the zoom altitudes.

If you use more plausible data instead of the most optimistic, it will never occur.

TheGrunch
06-07-2010, 06:09 PM
*Updated the spreadsheet (http://spreadsheets.google.com/ccc?key=0Avb3JMLg1IVUdGpKX1dBd2tyN3Z4c25sUVBRMVVqb lE&hl=en) to use the figure of 330mph for the Spitfire and 566kph for the FW 190, the least optimistic speed for the Merlin 66 engined Spitfire IX at +18lbs/sq.in. that I have data for at ALL and the most optimistic speed for ANY FW 190 A8 that I have seen data for on a performance diagram that also describes the aircraft's condition (http://www.wwiiaircraftperformance.org/fw190/fw190-a8-25oct44.jpg). This is subject to change if more data is made available. All values used converted to KTS via Google retaining as many decimal places as Google felt like giving me.*
Awaiting instruction as to the correction required in the calculation. What's interesting is that the zoom advantage the Spitfire has is now 6 times larger than it was before with our service condition Spitfire at 335mph and our unverified condition FW 190 at 578kph.

trashcanUK
06-07-2010, 06:10 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content"> It is not about the truth, it is about proving me wrong </div></BLOCKQUOTE>
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content"> That is not how the physical world works. </div></BLOCKQUOTE>
You seem to be unable to make basic mathematical calculations in a correct manner therefore one can only take your view of physics with a pinch of salt http://forums.ubi.com/groupee_common/emoticons/icon_frown.gif
However the comedic value of your posts coupled with your misguided arrogance is just priceless. Many, many thanks for the entertainment you are providing. Please continue, I look forward to it every time I visit this site. Thank you http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif
Understand?

M_Gunz
06-07-2010, 06:26 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Kettenhunde:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content"> If so then what you describe are not findings so much as reporting success of method. </div></BLOCKQUOTE>

It is not about the truth, it is about proving me wrong, M_Gunz.

It is a simple fact, velocity is the most important factor in a zoom climb.

It is absolute fantasy for your games Spitfire to end up 200 feet above the Focke Wulf as per Wurkeri's original claim.

That is not how the physical world works. </div></BLOCKQUOTE>

That depends entirely on how you run your test. Why you keep going on how what they did shows IL2 is wrong is beyond me,
it's almost like you think he ran comparative trials in some manner other than what he did. First thing to find out is
just what was done in detail rather than a label and sweeping conclusion. IRL you would, here it's just head off as if
you knew what wasn't stated (logical default, must be as you see it) and get to "IL2 is very wrong be sure"-land.

TheGrunch
06-07-2010, 06:28 PM
Especially since I'm pretty certain that IL-2 produces a better approximation than static rectilinear equations for constant thrust and drag values performed on a calculator to one decimal place.

M_Gunz
06-07-2010, 06:34 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by TheGrunch:
*Updated the spreadsheet (http://spreadsheets.google.com/ccc?key=0Avb3JMLg1IVUdGpKX1dBd2tyN3Z4c25sUVBRMVVqb lE&hl=en) to use the figure of 330mph for the Spitfire and 566kph for the FW 190, the least optimistic speed for the Merlin 66 engined Spitfire IX at +18lbs/sq.in. that I have data for at ALL and the most optimistic speed for ANY FW 190 A8 that I have seen data for on a performance diagram that also describes the aircraft's condition (http://www.wwiiaircraftperformance.org/fw190/fw190-a8-25oct44.jpg). This is subject to change if more data is made available. All values used converted to KTS via Google retaining as many decimal places as Google felt like giving me.*
Awaiting instruction as to the correction required in the calculation. What's interesting is that the zoom advantage the Spitfire has is now 6 times larger than it was before with our service condition Spitfire at 335mph and our unverified condition FW 190 at 578kph. </div></BLOCKQUOTE>

How did you arrive at those values for thrust and drag? I can only assume they are averages.

Gaston444
06-07-2010, 06:35 PM
Quote, Xiolablu3: "How can you be any more wrong about everything?

Eric Brown = 2 kills

FW190 incredible high speed manouverability and roll rate.

Spitfire = Far better turning circle than FW190, particularly at lower/mid speeds.

Every single paper from the RAF at this time which talks about the Spitfire vs FW190 explains the Spitfire's far better turning circle. The Fw190 has a higher wing loading, is a similar type of design, has no slats or high lift devices and is also much heavier than the Spitfire. How COULD it have a smaller turning circle at lower speeds?
-------------------------------------------------------------------------------------------------------
-I stand corrected: I had read a lot from Eric Brown, and never heard about his two kills: Sorry: My mistake to have made this assumption... Thirty + kills still beats two kills though...

As for the rest, I already explained why sustained low-speed turns are not the same thing as instantaneous turns: You probably should NOT pull the FW-190A into the turn hard (especially at high speed!), but if started gently it could then sustain them better once started without a hard pull...

To help the poor initial turn transition is why the outer two guns were often removed in the "A" fighter models, in addition to that weight reduction being standard on the bomber versions, and not exclusive to them as is often assumed...

In the initial turn the Spitfire is of course far better in the first 180-270 (which is what is meant by the smaller "radius" in WWII, "radius" being mostly quoted for unsustained-type turns; thus high-speed turns nearer the REAL "Corner Speed"; thus around 350-400 MPH on most WWII types; thus the "doghouse" shape being pure fiction on most WWII types. Hmmm... It all fits together well doesn't it?), and comparatively especially so at high speed where it could often get on a Fw190A's tail in less than one 360...

I already explained at lenght why the shorter nose loads up the wing less with the engine pull in sustained turns, because of the reduced propeller-nose lenght leverage, but you only need to accept the obvious fact that it does out-turn the Me-109G...

I have found another combat (In Osprey's "Gryphon Spitfire aces") involving a Spitfire Mk XII: "I went into this terribly tight turn but still he (a Fw190A) had no trouble keeping up with me, until suddenly a flash appeared in his cockpit..."

Try to find a similar quote involving a Me-109G, not F... I have never seen one... Also, the Johnny Johnson text is demonstrative enough of AT LEAST a fairly close parity between the two types at low speed:

http://img30.imageshack.us/img.../jjohnsononfw190.jpg (http://img30.imageshack.us/img30/4716/jjohnsononfw190.jpg)

Given my quote of the Johnson text, it would be very useful if you reiterated here your explanation why a "vertical turn" is in fact WWII lingo for a 90 bank turn.... There are still plenty of folks out there clinging to their delusion that he meant vertical loopings "in an ever decreasing circle"... Roll eyes...

As for great Fw-190A elevator handling at high speed: Why not provide any kind of evidence of this patent absurdity?

Kurt Tank's quote of 7 G pulls with feather-light controls doesn't count; I'll explain later why Eric Brown's "sinking" quote comes into play here... It's that "sinking" feeling you know...

Gaston

TheGrunch
06-07-2010, 06:41 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by M_Gunz:
How did you arrive at those values for thrust and drag? I can only assume they are averages. </div></BLOCKQUOTE>
They are not mine, they are Kettenhunde's. I don't know how he derived them, he has stated the Cd0 he used for each aircraft though in the previous part of the thread if you're curious. I am just blindly inserting his calculation into a spreadsheet.

I am an economics undergraduate, not an aerospace engineer (I had to spend a couple of minutes reading a high-school physics wiki about rectilinear motion equations before I knew what this stuff meant), but I can do the maths part and that was what initially rang the alarm bells for me regarding Kettenhunde's statement that the faster aircraft will always zoom higher, using this model as proof.
If we alter the top speeds slightly WELL within acceptable levels of variation in production without reversing the speed hierarchy, we can produce the opposite result.

M_Gunz
06-07-2010, 06:48 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by TheGrunch:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by M_Gunz:
How did you arrive at those values for thrust and drag? I can only assume they are averages. </div></BLOCKQUOTE>
They are not mine, they are Kettenhunde's. I don't know how he derived them, he has stated the Cd0 he used for each aircraft though in the previous part of the thread if you're curious. I am just blindly inserting his calculation into a spreadsheet.

I am an economics undergraduate, not an aerospace engineer (I had to spend a couple of minutes reading a high-school physics wiki about rectilinear motion equations before I knew what this stuff meant), but I can do the maths part and that was what initially rang the alarm bells for me regarding Kettenhunde's statement that the faster aircraft will always zoom higher, using this model as proof.
If we alter the top speeds slightly WELL within acceptable levels of variation in production without reversing the speed hierarchy, we can produce the opposite result. </div></BLOCKQUOTE>

Assuming the averages were correct for one set of values, when you change the values but not the averages then it's forked.

Kettenhunde
06-07-2010, 07:04 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Assuming the averages were correct for one set of values, when you change the values but not the averages then it's forked. </div></BLOCKQUOTE>


Yep.

Grunch,

That Focke Wulf data is what the company reported to the RLM on 1 Nov 44 as aircraft's average speed.

http://www.wwiiaircraftperform...ngsdaten-1-10-44.jpg (http://www.wwiiaircraftperformance.org/fw190/leistungsdaten-1-10-44.jpg)

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content"> the faster aircraft will always zoom higher, using this model as proof. </div></BLOCKQUOTE>

That is a basic principle of aircraft performance, Grunch.

Like low wing loading means good turn performance....

TheGrunch
06-07-2010, 07:06 PM
Would you mind giving me the thrust and drag functions you used to calculate these values so I can make this spreadsheet a valid comparison again, then?

EDIT: Didn't see M_Gunz' post.

Kettenhunde
06-07-2010, 07:49 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">If we alter the top speeds slightly WELL within acceptable levels of variation in production without reversing the speed hierarchy, we can produce the opposite result. </div></BLOCKQUOTE>


Once again, try zooming to the same ending speed and see the result.....

I hardly think aerodynamic principles need to be re-written and it does not change the fact the Focke Wulf can zoom to advantage in a dogfight because it travels at a much higher speed.

It does not change the fact the Focke Wulf can still sustain a higher load factor at a higher speed than the Spitfire.

The fact also remains that in order to achieve a significant sustained turn performance advantage, the Spitfire must slow down some ~65 Knots slower than the Focke Wulf.

All of that sets up the conditions the Focke Wulf can zoom safely above the Spitfire and the dog fight is on.

M_Gunz,

Nobody is bashing your game. The claim was made that the Spitfire consistently zooms to 200 feet above the Focke Wulf in IL2 under the speeds listed.

Now I assumed that Wurkeri was smart enough to test the aircraft under the same conditions.

If those results can be consistently reproduced under the same conditions for each aircraft, then yes, something is very rotten as that is not how the physical world works.

Kettenhunde
06-07-2010, 07:56 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Would you mind giving me the thrust and drag functions you used to calculate these values so I can make this spreadsheet a valid comparison again, then? </div></BLOCKQUOTE>


Sure, if you will remove all the jabs at me for mistakes I have already explained from it.

TheGrunch
06-07-2010, 08:03 PM
For sure.

irR4tiOn4L
06-07-2010, 08:13 PM
What about the error in the equations you spoke of Kettenhunde?

Kettenhunde
06-07-2010, 08:34 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">What about the error in the equations you spoke of Kettenhunde? </div></BLOCKQUOTE>


I am still waiting on an expert to point it out.

TheGrunch
06-07-2010, 08:36 PM
Right then. More arguing tomorrow, no doubt. http://forums.ubi.com/images/smilies/88.gif Have fun gents.

irR4tiOn4L
06-07-2010, 11:03 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Kettenhunde:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">What about the error in the equations you spoke of Kettenhunde? </div></BLOCKQUOTE>


I am still waiting on an expert to point it out. </div></BLOCKQUOTE>

I dont think anyone will pick it up though

EDIT: Well i still dont see it.

I do have a question though - why are we reducing thrust to match drag, and why is gravity the only acceleration acting on the aircraft if we have thrust?

Or does that mean that because drag is changing, thrust has to be manipulated to eliminate its effects?

Also the a figure for gravity is slightly off, its supposed to be -32.174 or something, but i doubt thats it

JtD
06-07-2010, 11:12 PM
I would like to mention that I had the "polished" surface statement from a translated Fw data sheet (think it's been around on this forum), I checked that against the German version and there it is the paint finish. Error in the translation. So no A-8 data that I know is specifically for a polished surface.

578 km/h originates from a performance calculation report of Fw in January 1944 for the painted surface. Not verified through flight tests yet, and later changed to the 565 km/h seen on the chart TheGrunch linked.

JtD
06-07-2010, 11:20 PM
I'm not looking for any more errors in your calculation, Kettenhunde. Checked it, made my comments. Done with it. If I missed it, so be it. Lots to fix anyway.

As for proving things wrong - you're the one who want to prove something wrong, i.e. that the game is wrong. I have pointed out some significant errors and shortcomings in your method. That's all. You fix them, and come to the same conclusion you reached already, we'd have something new to discuss. End of story.

As far as I am concerned, the game does a pretty good job. It's using the same principles you use, just different input data and more sophisticated calculations. General results meet with expectations and match common sense.

irR4tiOn4L
06-07-2010, 11:39 PM
s = (V2 Vo2) / 2a = - (200 x 1.69)2 / (2)(-32.2) = -3382 / -64.4 = 1774 ft

Anyone know how to get sensible answers out of this equation?

EDIT:

Forget it, without rectilinear motion im clearly not equipped to solve this equation

M_Gunz
06-08-2010, 01:21 AM
That's for finding position given start and end velocities and an average acceleration.

M_Gunz
06-08-2010, 01:37 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by irR4tiOn4L:
I do have a question though - why are we reducing thrust to match drag, and why is gravity the only acceleration acting on the aircraft if we have thrust? </div></BLOCKQUOTE>

If you match thrust to drag so each cancels the other then what else is there but gravity accelerating the plane?
And the effect of gravity is very easy to compute.

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Or does that mean that because drag is changing, thrust has to be manipulated to eliminate its effects? </div></BLOCKQUOTE>

It has to be manipulated to -only- eliminate the drag. Be sure that is not being done in every test shown here!

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Also the a figure for gravity is slightly off, its supposed to be -32.174 or something, but i doubt thats it </div></BLOCKQUOTE>

Error being on the order of .026/32.174 = .00008081... = .008%
Are you sure that 32.2 ft/s/s is not close enough given the precision of the other values being used?

irR4tiOn4L
06-08-2010, 02:01 AM
Is there some specific way to solve that formula though? Because obviously -3382/-64.4 =/ 1774


For gravity im sure 32.2 is accurate enough.

I assume the aircraft is zooming vertically?

Im having a tough time seeing the error Kettenhunde is talking about, because im having a tough time seeing the way this works at all

M_Gunz
06-08-2010, 02:36 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by irR4tiOn4L:
s = (V2 Vo2) / 2a </div></BLOCKQUOTE>

This above is recognizably -from- a position formula. I just don't know where the time elements are or why the squares
are not ^2 instead of 2.

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content"> = - (200 x 1.69)2 / (2)(-32.2) = -3382 / -64.4 = 1774 ft </div></BLOCKQUOTE>

The rest... looks even more screwy.

There might be a rational explanation but you'd have to ask the person who made that.

irR4tiOn4L
06-08-2010, 03:02 AM
Kettenhunde?

How does someone not familiar with rectilinear motion equations use your formula?

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">:Kettenhunde
Here is a simple exercise to illustrate the use of the rectilinear motion equations applied to a zoom climb.

Find: Potential Energy(PE), Kinetic Energy(KE) and Total Energy (TE) of aircraft under the following conditions:
Weight= 14,000 lb
Altitude = 10,000 ft
Airspeed = 200 KTAS

PE= Wh = (14,000 lb) (10,000 ft) = 14 x 107 ft-lb
KE = mV2 = (14,000/32.2)( 200 x1.69)2 = 24,835,652. = 2.48 x 107 ft-lb
TE = PE + KE = 16.48 x 107 ft-lb

If this aircraft performed a zoom climb to zero airspeed assuming no changes in thrust and drag (Drag would consistently decrease during the maneuver, where if thrust levers stayed the same, thrust would actually stay close to the same. So this exercise assumes that you are reducing thrust to match drag), What would the altitude be when the aircraft reaches zero speed at the top of the climb before it starts a tailslide?

Either solve by knowing that total energy stays the same. This is a trading of kinetic energy for potential energy
Total energy1 = Total energy2
PE1 + KE1 = PE2 + KE2
16.48 x 107 = PE2 + KE2
KE2 = 0
PE2 =Wh = 16.48 x 107 = 16.48 x 107 ft-lb / 14000 lb = 11771 ft

Or solve using rectilinear motion equations only acceleration acting on the aircraft is from gravity

s = (V2 Vo2) / 2a = - (200 x 1.69)2 / (2)(-32.2) = -3382 / -64.4 = 1774 ft
s = the altitude gained. so 1774 +10,000 = 11774 ft. within the error of significant digits these answers are the same.

Think about it awhile </div></BLOCKQUOTE>

That last sentence is pretty prophetic

TheGrunch
06-08-2010, 04:06 AM
Solve for s in equation 5.4 from this page (http://en.wikibooks.org/wiki/FHSST_Physics/Rectilinear_Motion/Equations_of_Motion), irrational, and you get the right formula. Kettenhunde's one is only wrong formatting-wise, but you had to know the equation already to work that out.

M_Gunz
06-08-2010, 04:11 AM
Using Newton's Motion Equations which be sure are included in the rectilinear motion equations...
I don't have to take mass into consideration which with gravity as the only acceleration source is just fine.

initial position = s0 = 0
initial velocity = v0 = 200kts = 200 * 1.15 kts/mph * 5280 ft/mile * 1/3600 hr/sec = 337 ft/sec
[note that (1.15 kts/mph * 5280 ft/mile * 1/3600 hr/sec) = knots to ft/sec conversion 1.6866666 ~= 1.69 used by K]
gravity in this case = a = -32.2 ft/sec/sec = -32.2 ft/sec^2

Our end velocity is to be 0. We can find out how long it will take gravity to eat the initial 337 ft/sec.

v = 0 = v0 + a * t
0 ft/sec = 337 ft/sec - 32.2 ft/sec^2 * T sec
T * 32.2 = 337
T = 10.466

position = s = s0 + V0*t + a * t^2 / 2

s = 0 + 337 ft/sec * 10.466 sec - 16.1 ft/sec^2 * (10.466 sec)^2
s = 10.466 * 337 ft - 16.1 ft * 10.466^2
s = 3527 ft - 1763 ft = 1764 ft including very small roundoff errors is 10 ft different, I won't cry.

irR4tiOn4L
06-08-2010, 04:20 AM
Excellent, thanks guys.

But what is that fundamental error he mentioned then? 'straight out of physics 101'

Kettenhunde
06-08-2010, 04:52 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content"> why is gravity the only acceleration acting on the aircraft if we have thrust? </div></BLOCKQUOTE>

If we have thrust, it is not the only acceleration acting on the aircraft.

TheGrunch
06-08-2010, 04:59 AM
In that case it's because thrust = drag so mathematically they cancel each other out. It's not that gravity's the only acceleration. Sorry, didn't see that bit irrational.

irR4tiOn4L
06-08-2010, 06:12 AM
Thats not the fundamental error though is it?

I mean i accepted that when Kettenhunde said gravity was the only acceleration acting on the aircraft, he meant because thrust = drag and thus is cancelled out, and lift is probably not relevant because we are zooming vertically

I still fail to see the error

TheGrunch
06-08-2010, 06:54 AM
So do I. There was a post that appeared briefly on the subject that suggested it was something that I thought was already accounted for, but it was swiftly deleted so I guess we can presume that it was not the right answer. I'm quite interested to know what it is! http://forums.ubi.com/images/smilies/16x16_smiley-surprised.gif

irR4tiOn4L
06-08-2010, 07:10 AM
lol this is getting more intriguing than the actual discussion!

Everyone loves puzzles it seems

TheGrunch
06-08-2010, 07:25 AM
If pub-quiz met science...

irR4tiOn4L
06-08-2010, 07:42 AM
Theyd both get drunk, sleep together and never get any work done?

TheGrunch
06-08-2010, 07:50 AM
Probably right after science got all the answers right and won the crate of alcopops.

irR4tiOn4L
06-08-2010, 07:54 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by TheGrunch:
Probably right after science got all the answers right and won the crate of alcopops. </div></BLOCKQUOTE>

Dunno, to win you have to answer A,B,C or D and you know science - it wouldnt say any of those was correct

Pub quiz could just cheat though..

TheGrunch
06-08-2010, 07:58 AM
I'll find out in a minute when I go to the pub with some science students. http://forums.ubi.com/images/smilies/88.gif
Hopefully the mystery will be solved soon!

irR4tiOn4L
06-08-2010, 08:35 AM
Fingers crossed!

Kettenhunde
06-08-2010, 09:24 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Kettenhunde's one is only wrong formatting-wise, </div></BLOCKQUOTE>


It is not wrong at all...the formula is correct.

In fact those are the same formulas. One is just reduced to solve for distance along the axis.

V^2 = Vo^2 + 2a(x-xo)


V^2 = Vo^2 + 2a *delta x

V^2 - Vo^2 = 2a *delta x

delta x = (V^2 - Vo^2)/2a

TheGrunch
06-08-2010, 09:40 AM
You'd just made a typo so there was no ^ symbol, which looked like multiplication instead of an exponent.
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Kettenhunde:
s = (V2 Vo2) / 2a = - (200 x 1.69)2 / (2)(-32.2) = -3382 / -64.4 = 1774 ft </div></BLOCKQUOTE>
That's what I meant. I don't know how you were supposed to get that from "formatting-wise", words failed me for a second. http://forums.ubi.com/groupee_common/emoticons/icon_redface.gif

irR4tiOn4L
06-08-2010, 09:42 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Kettenhunde:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Kettenhunde's one is only wrong formatting-wise, </div></BLOCKQUOTE>


It is not wrong at all...the formula is correct.

In fact those are the same formulas.

V^2 = Vo^2 + 2a(x-xo)


V^2 = Vo^2 + 2a *delta x

V^2 - Vo^2 = 2a *delta x

delta x = (V^2 - Vo^2)/2a </div></BLOCKQUOTE>

I think what they were trying to tell me is that I needed to understand rectilinear equations in order to actually use your formula - for example, trying to divide -3382/-64.4 did not equal 1774 feet, and that confused me.

M_Gunz showed me how to do it a different way


In any case, what was the error?

TheGrunch
06-08-2010, 09:47 AM
It's just a typo, irrational. It was meant to be:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content"> s = (V^2 Vo^2) / 2a = - (200 x 1.69)^2 / (2)(-32.2) = -114244 / -64.4 = 1774 ft </div></BLOCKQUOTE>

Kettenhunde
06-08-2010, 09:50 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">I just don't know where the time elements are </div></BLOCKQUOTE>

The time elements are in the units.

They are already broken down into "per unit of time". Obviously that unit is a second.

Instead of finding distance over a range of velocity, we can use that time relationship per unit to determine how much time any motion will require.

irR4tiOn4L
06-08-2010, 09:50 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by TheGrunch:
It's just a typo, irrational. It was meant to be:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content"> s = (V^2 Vo^2) / 2a = - (200 x 1.69)^2 / (2)(-32.2) = -114244 / -64.4 = 1774 ft </div></BLOCKQUOTE> </div></BLOCKQUOTE>

Ahh! Thats it!

Id actually tried squaring that part but somehow i never tried it in the second half instead of 3382 - because i was trying to find out how 3382 was arrived at in the first place!

Makes sense now

Kettenhunde
06-08-2010, 09:53 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">You'd just made a typo so there was no ^ symbol, which looked like multiplication instead of an exponent. </div></BLOCKQUOTE>


I see, multiplication would be 2V and not V2. It is not wrong, just another way of writing it.

irR4tiOn4L
06-08-2010, 09:53 AM
So Kettenhunde, was your statement that only gravity is accelerating the airplane (which is pretty much true, since thrust=drag and they cancel), despite thrust being used to counteract drag, the 'fundamental error straight from physics 101' that you spoke of, or was it something else?

TheGrunch
06-08-2010, 09:54 AM
Ahhhh, right. I've seen both for multiplication, must be a European thing. http://forums.ubi.com/groupee_common/emoticons/icon_wink.gif

irR4tiOn4L
06-08-2010, 09:55 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Kettenhunde:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">You'd just made a typo so there was no ^ symbol, which looked like multiplication instead of an exponent. </div></BLOCKQUOTE>


I see, multiplication would be 2V and not V2. It is not wrong, just another way of writing it. </div></BLOCKQUOTE>

The major typo you had was in the second half - you wrote "-3382/-64.4 = 1774 feet" and that confused me to no end, because it was supposed to be "-114244/-64.4 = 1774 feet". Grunch kindly pointed out that it was a typo

Kettenhunde
06-08-2010, 09:59 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">thrust=drag </div></BLOCKQUOTE>


Thrust does not equal drag as the airplane is not in a steady state condition. It is trying to move to that condition but we are not letting it.

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content"> major typo you had was in the second half </div></BLOCKQUOTE>

Got it...everybody clear so far?

irR4tiOn4L
06-08-2010, 10:02 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Kettenhunde:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">thrust=drag </div></BLOCKQUOTE>


Thrust does not equal drag as the airplane is not in a steady state condition.

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content"> major typo you had was in the second half </div></BLOCKQUOTE>

Got it...everybody clear so far? </div></BLOCKQUOTE>

That was a condition of your scenario though;

remember what you specified;

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">
If this aircraft performed a zoom climb to zero airspeed assuming no changes in thrust and drag (Drag would consistently decrease during the maneuver, where if thrust levers stayed the same, thrust would actually stay close to the same. So this exercise assumes that you are reducing thrust to match drag), What would the altitude be when the aircraft reaches zero speed at the top of the climb before it starts a tailslide?

Either solve by knowing that total energy stays the same. This is a trading of kinetic energy for potential energy
Total energy1 = Total energy2
PE1 + KE1 = PE2 + KE2
16.48 x 107 = PE2 + KE2
KE2 = 0
PE2 =Wh = 16.48 x 107 = 16.48 x 107 ft-lb / 14000 lb = 11771 ft

Or solve using rectilinear motion equations only acceleration acting on the aircraft is from gravity

s = (V2 Vo2) / 2a = - (200 x 1.69)2 / (2)(-32.2) = -3382 / -64.4 = 1774 ft
s = the altitude gained. so 1774 +10,000 = 11774 ft. within the error of significant digits these answers are the same.

Think about it awhile. </div></BLOCKQUOTE>

Or did i get that wrong somehow? I guess you couldve meant that thrust compared to drag doesnt change, but then gravity wouldnt be the only acceleration acting on the aircraft right?

If thrust =/ drag, how can gravity be the only acceleration acting on the aircraft?

Kettenhunde
06-08-2010, 10:06 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">That was a condition of your scenario though;

remember what you specified; </div></BLOCKQUOTE>


Yes that is correct. We have our problems crossed.

I was explaining what is going on with our Spitfire/Focke Wulf performance not an airplane with the throttle reduced to ensure thrust = drag.

irR4tiOn4L
06-08-2010, 10:11 AM
Ok well anyway, go on - what was the mistake that you were waiting on people here to pick up?

Kettenhunde
06-08-2010, 10:20 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">If thrust =/ drag, how can gravity be the only acceleration acting on the aircraft? </div></BLOCKQUOTE>

It is not the only accelerating force acting on the aircraft.

M_Gunz
06-08-2010, 10:59 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Kettenhunde:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">If thrust =/ drag, how can gravity be the only acceleration acting on the aircraft? </div></BLOCKQUOTE>

It is not the only accelerating force acting on the aircraft. </div></BLOCKQUOTE>

That's like saying I don't have a hat and being told no but your umbrella keeps your head from the rain.

Balanced forces do not accelerate an object, now do they?

I can put my hand on the wall and so exert force without accelerating the wall one bit. The wall applies
equal and opposite force on my hand which I feel. The forces cancel, neither accelerates anything, there
is no acceleration nor accelerating forces, only forces which act on each other.

arjisme
06-08-2010, 03:45 PM
So, Kettenhunde, are you going to enlighten us? I'm certainly interested in seeing what you say everyone has missed.

Kettenhunde
06-08-2010, 07:28 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Balanced forces do not accelerate an object, now do they? </div></BLOCKQUOTE>

Not the same frame of reference.

We do use the relationship of balanced forces to determine aircraft performance.

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content"> So, Kettenhunde, are you going to enlighten us? I'm certainly interested in seeing what you say everyone has missed. </div></BLOCKQUOTE>

Not yet.

irR4tiOn4L
06-08-2010, 07:43 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by M_Gunz:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Kettenhunde:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">If thrust =/ drag, how can gravity be the only acceleration acting on the aircraft? </div></BLOCKQUOTE>

It is not the only accelerating force acting on the aircraft. </div></BLOCKQUOTE>

That's like saying I don't have a hat and being told no but your umbrella keeps your head from the rain.

Balanced forces do not accelerate an object, now do they?

I can put my hand on the wall and so exert force without accelerating the wall one bit. The wall applies
equal and opposite force on my hand which I feel. The forces cancel, neither accelerates anything, there
is no acceleration nor accelerating forces, only forces which act on each other. </div></BLOCKQUOTE>

Kettenhunde was responding to my statement that 'if thrust does NOT equal drag' - in which he correctly stated gravity would not be the only acceleration acting on the aircraft - if thrust=/drag, some net acceleration would be present.

Moreover, Kettenhunde's original condition - that thrust is lowered to match drag, cancelling out, certainly accorded with his statement that 'gravity was the only acceleration acting on the aircraft' - excluding, of course, lift (vertical zoom?).

So i still dont see what the error was

M_Gunz
06-08-2010, 08:05 PM
!=

irR4tiOn4L
06-08-2010, 08:10 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by M_Gunz:
!= </div></BLOCKQUOTE>

I might use that from now on.

There are many ways people come up with
http://able2know.org/topic/25688-1

M_Gunz
06-09-2010, 03:37 AM
Avoid /= as that is a shortcut divide operation: x /= 2 takes whatever value is in x, divides by 2 and stores result in x.

I'm not sure what compilers/interpreters some of those people use but I see the programmers identify themselves....

TheGrunch
06-09-2010, 06:36 AM
=/= is pretty hard to mix up.

M_Gunz
06-09-2010, 08:08 AM
! is boolean for NOT
!= is not equal
The letters NE as also used.
If you're not writing code then the most clear are the words 'not equal'.

=/ looked like a typo of some kind to me and since previous discussion was around T=D I stuck with that.

Of course it could have been Forth code in which case you can literally redefine things however you want.

JtD
06-09-2010, 11:29 AM
About 10 pages since we have a computer simulation backed up by another computer simulation on one side of the zoom climb argument, and a incredibly faulty, massively simplified calculation backed up with an "I am right" statement on the other.

While there was the promise for an improved calculation to have been posted a couple of days ago, we haven't got to see anything yet.

Looks like this issue is pretty much closed.

Should we get back to the 1500m reversal? There it's two computer simulations against the result of an unknown calculation backed up with an "I am right" statement. Much more open.

Kettenhunde
06-09-2010, 01:10 PM
It is far from finished. You don't seem to understand that all higher order calculations are based off the vector the so called "simplified" calculation determines.

That vector is how we derive our changes in position.

Nothing higher order is going to change the relative performance lineup, only the specific position of the aircraft.

If your game consistently places the Spitfire above the Focke Wulf at the velocities Wurkeri claims, it is wrong.

JtD
06-09-2010, 01:25 PM
The way I know debates you need to come up with a valid argument regarding the issue - for instance, the improved and corrected calculation that has been promised days ago. At this moment, only one side has valid arguments, so no debate.

Just saying "it is because I say so" doesn't cut the mustard.

arjisme
06-09-2010, 01:59 PM
Is the fundamental debate at the moment over whether a faster aircraft that is co-alt with an enemy aircraft will be higher than the enemy aircraft after a zoom climb of a certain duration?

JtD
06-09-2010, 02:34 PM
No, it's about a Spitfire LF MkIX @ 18lb and a Fw 190A-8 @ 1.58 ata starting a zoomclimb each at top level speed at sea level and which one's going to end up higher.

arjisme
06-09-2010, 02:47 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by JtD:
No, it's about a Spitfire LF MkIX @ 18lb and a Fw 190A-8 @ 1.58 ata starting a zoomclimb each at top level speed at sea level and which one's going to end up higher. </div></BLOCKQUOTE>That's essentially what I said, isn't it? Except for you being specific about the aircraft, isn't one faster than the other when at top speed?

Also, since that is the debate, can you define for me what is meant by "zoom climb." When are you in it and when does it end?

JtD
06-09-2010, 03:03 PM
Yes, it is what you said but the important difference is that this one is specific.

A zoom climb is a climb where the speed cannot be maintained. Think that's the best definition I have heard.

As to the particulars of that climb, they haven't been defined. Just that they start at sea level from level top speed. Only thing else I consider important is to make sure you state the conditions clearly so others can put your results into the right perspective.

arjisme
06-09-2010, 03:06 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by JtD:
A zoom climb is a climb where the speed cannot be maintained. Think that's the best definition I have heard.
</div></BLOCKQUOTE>So climb until you stall? I think some of the differences are around what exactly is considered a zoom climb. Maybe its a climb that is faster than the aircraft's best sustained climb rate? Once it slows to that point, it becomes a powered climb?

JtD
06-09-2010, 03:18 PM
It's up to you, really. You can still zoom climb below your best climb speed, but of course you don't have to.

Kettenhunde
06-09-2010, 03:33 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">for instance, the improved and corrected calculation that has been promised days ago. </div></BLOCKQUOTE>

You deliberately seem to misquote me. I said I would clean up the calculation and I did.

There is no reason to do a higher order calculation as the outcome is the same.

The airplanes path is not a straight line vector and higher order calculations will only tell you the position of the aircraft relative to the vector. It will not change the altitude gained in the zoom climb.

A zoom climb is just an unsteady climb profile.

You can zoom to whatever speed the pilot chooses to included zero velocity.

arjisme
06-09-2010, 05:47 PM
"an unsteady climb profile" doesn't help me very much, sorry. I'm slow, I guess, but I don't understand what that might mean.

I did some digging via Google and came up with a couple of definitions. One is basically what I proposed: a climb rate that is higher than the sustained best rate of climb the aircraft can perform.

Another definition is a zoom climb is a climb where the pilot tries to convert his speed to altitude. That one is a little harder to grasp, for me. It might mean the same thing as what Kett was proposing above. I guess it means however fast you are going, you point your nose up high enough so that you gain altitude while decelerating (due to gravity). Power on or off, you decelerate as you trade current speed for alt. That definition is not the same as the first one, however.

Bottom line: I think you guys need to agree on what zoom climb means before you can hope to reach an agreement in this debate.

M_Gunz
06-09-2010, 08:23 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Kettenhunde:
A zoom climb is just an unsteady climb profile. </div></BLOCKQUOTE>

Unsteady as opposed to steady means unchanging or sustained?
Is a steady speed loss acceptable as an unsteady climb profile?

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">The airplanes path is not a straight line vector </div></BLOCKQUOTE>

Huh? Why not? Especially in a vertical or near-vertical zoom?

I'm at a loss on both counts btw.

Kettenhunde
06-09-2010, 08:28 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">"an unsteady climb profile" doesn't help me very much, sorry. I'm slow, I guess, but I don't understand what that might mean. </div></BLOCKQUOTE>


In steady state performance there is no acceleration on the body axis reference of the aircraft.

In general, that means the acceleration at the CG is zero.

arjisme
06-09-2010, 08:39 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Kettenhunde:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">"an unsteady climb profile" doesn't help me very much, sorry. I'm slow, I guess, but I don't understand what that might mean. </div></BLOCKQUOTE>


In steady state performance there is no acceleration on the body axis reference of the aircraft.

In general, that means the acceleration at the CG is zero. </div></BLOCKQUOTE>OK. I take that to mean the same thing as the 2nd definition I provided then. The CG is decelerating throughout a zoom climb. Although, your definition allows that it could be accelerating. I guess if I was flying level at just above stall speed with a low power setting, I could then max power and pull up to begin a shallow climb. That might result in me accelerating during the initial part of that climb, purely by the added power. That would count as a zoom climb too, then, right?

M_Gunz
06-09-2010, 09:28 PM
He stated that a zoom climb is an unsteady climb profile so there would have to be acceleration of the CG.

However that is not the same as saying that unsteady acceleration equals a zoom climb.
A violin has strings and so does a guitar but a violin is not a guitar.

JtD
06-09-2010, 10:29 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by ar****e:

Bottom line: I think you guys need to agree on what zoom climb means before you can hope to reach an agreement in this debate. </div></BLOCKQUOTE>

I don't think that the definitions are that different. Maybe in the words they use, but not in what they mean in terms of flying. At any rate, the differences in the details of the definition didn't matter so far.

JtD
06-09-2010, 10:41 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Kettenhunde:

You deliberately seem to misquote me. I said I would clean up the calculation and I did. </div></BLOCKQUOTE><BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Kettenhunde at 8:40 of June 6th:
Tonight I will clean it up and post the corrections. </div></BLOCKQUOTE>

So where is it?

OTOH, given the capacity for reflection you demonstrated with the sin(45) error, it's probably not worth it.

megalopsuche
06-10-2010, 12:13 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by JtD:
OTOH, given the capacity for reflection you demonstrated with the sin(45) error, it's probably not worth it. </div></BLOCKQUOTE>

Oh snap! http://forums.ubi.com/images/smilies/crackwhip.gif

This thread is definitely going platinum.

M_Gunz
06-10-2010, 12:59 AM
It might be good to define how a comparative zoom should be run rather than comparing different zooms.
It might be good to make clear what major factors besides energy affect any certain test.
Getting the speed each plane starts the actual post-transition zoom as known should go a long way towards
not reading how IL2 is wrong based on pre-transition speeds 2 or 3 times per page though clarity in the
test conditions is also needed there.

Could we perhaps find some kind of T-D or SEP data from detailed rise data in vertical zooms since we know
gravity and can(?) attribute difference in zoom from T=D profile to specific thrust minus specific parasitic
drag (if there are such things!) with change in speed, factoring in weight? IE, possibly get something else
useful (at least useful in IL2) out of tests besides end-height numbers and an uber-gold ribbon for the winner?

M_Gunz
06-10-2010, 01:02 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by megalopsuche:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by JtD:
OTOH, given the capacity for reflection you demonstrated with the sin(45) error, it's probably not worth it. </div></BLOCKQUOTE>

Oh snap! http://forums.ubi.com/images/smilies/crackwhip.gif

This thread is definitely going platinum. </div></BLOCKQUOTE>

It used to be "20+ pages, be sure". Now I can see going to 20+ PARTS!

RegRag1977
06-10-2010, 03:47 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by JtD:
No, it's about a Spitfire LF MkIX @ 18lb and a Fw 190A-8 @ 1.58 ata starting a zoomclimb each at top level speed at sea level and which one's going to end up higher. </div></BLOCKQUOTE>

Hi JtD,

"Fw190 vs Spitfire VB

The Fw190 was compared with a Spitfire VB from an operational squadron for speed and all-round manoeuvrability at heights up to 25,000 feet. The The Fw190 is superior in speed at all heights, and the approximate differences are as follows:

At 1,000 ft the Fw 190 is 25-30 mph faster than the Spitfire VB
At 3,000 ft the Fw 190 is 30-35 mph faster than the Spitfire VB
At 5,000 ft the Fw 190 is 25 mph faster than the Spitfire VB
At 9,000 ft the Fw 190 is 25-30 mph faster than the Spitfire VB
At 15,000 ft the Fw 190 is 20 mph faster than the Spitfire VB
At 18,000 ft the Fw 190 is 20 mph faster than the Spitfire VB
At 21,000 ft the Fw 190 is 25 mph faster than the Spitfire VB
At 25,000 ft the Fw 190 is 20-25 mph faster than the Spitfire VB

Climb.
The climb of the Fw 190 is superior to that of the Spitfire VB at all heights. The best speed for climbing are approximately the same, but the angle of the FW 190 is considerably steeper. Under maximum continuous climbing conditions the climb of the FW 190 is about 450 ft/min better up to 25,000 ft.

With both aircraft flying at high cruising speed and then pulling up into a climb, the superior climb of the Fw190 is even more marked. When both aircraft are pulled up into a climb from a dive, the Fw190 draws away very rapidely and the pilot of the Spitfire has no hope of catching it.

Dive.Comparative dives between the two aircraft have shown that the Fw190 can leave the Spitfire with ease, particularly during the initial stages.

Manoeuvrability. The manoeuvrability of the Fw 190 is better than that of the Spitfire VB except in turning cicles, when the Spitfire can quite easily out-turn it. The Fw190 has better accereation under all conditions of flight and this must obviously be the most useful during combat.
When the Fw190 was in a turn and was attacked by the Spitfire, the superior rate of roll enabled it to flick into a diving turn in the opposite direction. The pilot of the Spitfire found great difficulty in following this manoeuvre and even prepared for it was seldom able to allow the correct deflection. A dive from this manoeuvre enabled the Fw190 to draw away from the Spitfire which was forced to break off the attack.
Several flights were carried out to ascertain the best evasive manoeuvres to adopt if 'bounced'. It was found that if the Spitfire was cruising at low speed and was 'bounced' fy the Fw 190, it was easliy caught up even if the Fw190 was sighted when well out of range, and the Spitfire was then forced to take avoiding action by using its superiority in turning cicles. If on the other hand the Spitfire was flying at maximum continuous cruising and was 'bounced' under the same conditions, it had a reasonable chance of avoiding being caught by opening the throttle and going into a shallow dive, provided the Fw 190 was seen in time. This forced the Fw190 into a stern chase and although it eventually caught the Spitfire, it took some time and as a result was drawn a considerable distance away from its base. This is a particularly useful method of evasion for the Spitfire if it is 'bounced' when returning from a sweep. This manoeuvre has been carried out during recent operations and has been sucessful on several occasions.
If the Spitfire VB is 'bounced' it is thought unwise to evade by diving steeply, as the Fw 190 will have little difficulty in catching up owing to its superiority in the dive.
The above trials have shown that the Spitfire VB must cruise at high speed when in an area where enemy fighters can be expected. It will then, in addition to lessening the chances of being successfully 'bounced', have a better chance of catching the Fw190, particularly if it has the advantage of surprise.

Fw190 versus Spitfire IX

The Focke Wulf was compared with a fully operational Spitfire IX for speed and manoeuvrability at heights up to 25,000 ft. The Spitfire IX at most heights is slightly superior in speed to the Fw 190, and the approximate differences in speeds at various heights are as follows:

At 2,000 ft the Fw 190 is 7-8 mph faster than the Spitfire IX
At 5,000 ft the Fw 190 and the Spitfire IX are approximately the same
At 8,000 ft the Spitfire IX is 8 mph faster than the Fw 190
At 15,000 ft the Spitfire IX is 5 mph faster than the Fw 190
At 18,000 ft the Fw 190 is 3 mph faster than the Spitfire IX
At 21,000 ft the Fw 190 and the Spitfire IX are approximately the same
At 25,000 ft the Spitfire is 5-7 mph faster than the Fw 190

Climb. During comparative climbs at various heights up to 23,000 feet, with both aircraft flying under maximum climbing conditions, little difference was found between the two aircraft although on the whole the Spitfire IX was slightely better.
Above 22,000 feet the climb of the Fw 190 is falling off rapidly, whereas the climb of the Spitfire is increasing. When both aircraft were flying at high cruising speed and were pulled up into a climb from level flight, the Fw190 had a slight advantage in the initial stages of the climb due to its better acceleration. This superiority was slightly increased when both aircraft were pulled up into a climb from a dive.
It must be appreciated that the differences between the two aircraft are only slight and that in actual combat the advantage in climb will be with the aircraft that has the initiative.

Dive. The Fw 190 is faster than a Spitfire IX in a dive, particularly during the initial stage. This superiority is not as marked as with the Spitfire VB

Manoeuvrability. The Fw 190 is more manoeuvrable than the Spitfire IX except in turning cicles, when it is out-turned without difficulty.
The superior rate of roll of the Fw190 enabled it to avoid the Spitfire IX if attacked in a turn by flicking over into a diving turn in the opposite direction, and as with the Spitfire VB, the Spitfire IX had Great Difficulty in following this manoeuver. It would have been easier for the Spitfire IX to follow the Fw190 in a diving turn if its engine had been fitted with a negative 'g' carburattor, as this type of engine with the ordinary carburator cuts very easily.
The Spitfire IX's worst heights for fighting the Fw 190 were between 18,000 and 22,000 feet and below 3,000 feet. At these heights the Fw190 is a little faster.
Both aircraft 'bounced' one another in order to ascertain the best evasive tactics to adopt. The Spitfire IX could not be caught when 'bounced' if it was cruising at high speed and saw the Fw190 when well out of range. When the Spitfire IX was cruising at low speed its inferiority in acceration gave the Fw190 a reasonable chance of catching it up and the same applied if the position was reversed and the Fw 190 was'bounced' by the Spitfire IX, except that overtaking tok a little longer.
The initial acceleration of the Fw 190 is better than the Spitfire IX under all condition of flight, except in level flight at such altitudes where the Spitfire has a speed advantage and then , provided the Spitfire is cruising at high speed, there is little to choose between the acceleration of the two aircraft.
Te general impression gained by the pilots taking part in the trial is that the Spitfire IX compares favourably with the Fw190 and that provided the Spitfire has the initiative, it has undoubtedly a good chance of shooting the Fw190 down."

I found this in "World War II Fighter conflict, a comparative study on the evolution of aircraft and tactics, Great Britain, USA, Germany, USSR, Japan, France, Italy" by Alfred Price, printed in 1975, (p.106, p.107 and p.108). The trials were probably made between a captured Fw 190 A-3 vs and an early Merlin 61 powered Spitfire MkIX (? I'm not sure, i think Price confused things with carburattors: AFAIK the Spitfires did no longer suffer from Neg G with the Mk.IX?).

From what i understood of it, the general trend (with faster aircraft zooming higher) seems to be respected, and it seems accentuated when out of a dive. The next striking thing for me is how the two aircraft seems similar to the author and even to the Spit pilots that flew these trials.

Anyway, I hope this can help answering the question, even if it is not anything like a definitive answer.
Maybe a good way to shake the Spitfire off is to first dive to optimal speed, then zoom climb, and before the end of the zoom slightly turn, and if the spitfire follows, the flick on the opposite direction in a diving turn to a neutral position.

Just my two cents, because to me, having a Spit on my six in actual combat means drag and bag or if alone run away, not because of the relative performances of the two aircraft but rather because this is what even a Spitfire pilot would do according to the extract i posted!

TinyTim
06-10-2010, 04:47 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by RegRag1977:
The climb of the Fw 190 is superior to that of the Spitfire VB at all heights. The best speed for climbing are approximately the same, but the angle of the FW 190 is considerably steeper. </div></BLOCKQUOTE>

This is a part where IL-2 in my opinion doesn't reflect reality with the greatest fidelity, since the IL-2 1946 situation is completely different.

M_Gunz
06-10-2010, 06:41 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by TinyTim:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by RegRag1977:
The climb of the Fw 190 is superior to that of the Spitfire VB at all heights. The best speed for climbing are approximately the same, but the angle of the FW 190 is considerably steeper. </div></BLOCKQUOTE>

This is a part where IL-2 in my opinion doesn't reflect reality with the greatest fidelity, since the IL-2 1946 situation is completely different. </div></BLOCKQUOTE>

This is where you should wonder about some of the picture of reality you've been given.

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by TinyTim quoting RegRag1977 with added bold font segment for emphasis:
The climb of the Fw 190 is superior to that of the Spitfire VB at all heights. The best speed for climbing are approximately the same, but the angle of the FW 190 is considerably steeper. </div></BLOCKQUOTE>

What angle is told here? Angle of climb or angle of pitch of the aircraft? It does not exactly say. What is assumed?
It says the angle of the FW 190 and yet somehow most people who post that quote inject 'climb' before 'angle'.

Do you know what Spitfire VB was used in that test? Do you know what Spitfire VB is is modeled in IL2 labeled as 1941
Spitfire VB? Surprise! It was told years ago that our 1941 Spit VB was mislabeled and is really August 1942 Spit VB,
check the engine in the Aircraft Guide. Another surprise! The Spit VB used in that test was one of the first few made
and had been "wrung out" in hard tests, just back from a test-flying tour in the US.

Sure they used a Spit VB and therefore it must be equal to all other Spit VBs since the name is the same?

This is how it works when segments of reports are taken for whole truth. The distorted picture becomes the new reality.

Last question: do you know how many times and how far back that bit of context has been used as 'proof' of how all
FW 190A 3s should compare to all Spitfire VBs?

RegRag1977
06-10-2010, 07:34 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by M_Gunz:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by TinyTim:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by RegRag1977:
The climb of the Fw 190 is superior to that of the Spitfire VB at all heights. The best speed for climbing are approximately the same, but the angle of the FW 190 is considerably steeper. </div></BLOCKQUOTE>

This is a part where IL-2 in my opinion doesn't reflect reality with the greatest fidelity, since the IL-2 1946 situation is completely different. </div></BLOCKQUOTE>

This is where you should wonder about some of the picture of reality you've been given.

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by RegRag1977:
The climb of the Fw 190 is superior to that of the Spitfire VB at all heights. The best speed for climbing are approximately the same, but the angle of the FW 190 is considerably steeper. </div></BLOCKQUOTE>

What angle is told here? Angle of climb or angle of pitch of the aircraft? It does not exactly say. What is assumed?
It says the angle of the FW 190 and yet somehow most people who post that quote inject 'climb' before 'angle'.

Do you know what Spitfire VB was used in that test? Do you know what Spitfire VB is is modeled in IL2 labeled as 1941
Spitfire VB? Surprise! It was told years ago that our 1941 Spit VB was mislabeled and is really August 1942 Spit VB,
check the engine in the Aircraft Guide. Another surprise! The Spit VB used in that test was one of the first few made
and had been "wrung out" in hard tests, just back from a test-flying tour in the US.

Sure they used a Spit VB and therefore it must be equal to all other Spit VBs since the name is the same?

This is how it works when segments of reports are taken for whole truth. The distorted picture becomes the new reality.

Last question: do you know how many times and how far back that bit of context has been used as 'proof' of how all
FW 190A 3s should compare to all Spitfire VBs? </div></BLOCKQUOTE>

Hi M_Gunz,

Interesting what you say, i did not know about that Mk VB indeed. Could you precise the reference to this tests and do you have further information on both aircraft (on the Fw190A3, and also on the MkIX used? That would be nice of you!

(IMHO the word angle is not the misleading one, but it would rather be the expression: "The manoeuvrability of the Fw 190 is better than that of the Spitfire VB except in turning cicles, when the Spitfire can quite easily out-turn it.")

In fact the most interesting thing i thought i had found in the extract i posted (new to me) is of course the part dealing with the mk.IX Spitfire: i found it strange that the author considers it more or less similar to the Fw190A3 performances?

Quite frankly i don't care much about how the Fw190 and mkVB are modelled in game, and i don't really understand why this particular part seems so important to you?

BTW I assume that your second point is a quote from my post: http://forums.ubi.com/images/smilies/10.gif if so please change the part in bold characters please, since it is not in bold in my original post. Thanks http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif .

All this to say that to me it is of course the part on the MkIX that is important as it seems to confirm the trend that a faster aircraft zooms higher than a slower one, especially after a dive.

Of course i'm not at all trying to say that Alfred Price is right, i just don't have the knowledge to do such a thing. http://forums.ubi.com/groupee_common/emoticons/icon_confused.gif

M_Gunz
06-10-2010, 08:12 AM
i was replying to Tiny Tim who quoted you and bolded those words. He does seem concerned about the apparent
ubering of Spitfires in IL2 given the segments of the conclusion part of that one AFDU report.

Most if not all of the knowledge of the planes used and condition of them even during the test are in the
full text of the whole report which has been linked to here many times in the past. I don't have the full
report since losing a disk partition back in 2003, a year after the 'issue' was a hot button here before.
The really hard page to find that I've only seen posted here once ever is Page One where the modifications
to the FW to allow 1.42 ATA operation, I remember a restriction plate being removed but 'gots no docs'.

The difference between a first-run Spit VB and summer 1942 Spit VB engine is one of power. There are
members here with their own books on the subject and worth at least 5 pages of wrangling after which no
solid conclusion will have been reached unless you want to go with the last revis.. err, debater standing
method of truth-finding. When the difference amounts to less than 5% let alone 2-3 mph, I quit reading so
closely. Again, IL2 has no Spitfire VB representing any 1941-produced Spit VB regardless of labels, that
is official and statement of the error was posted here by Oleg Maddox and ignored periodically since.

JtD
06-10-2010, 09:11 AM
Hi RegRag1977, thanks for that quote and in particular for giving the source - I've recently been looking for that and just could not find it anymore.

I think some of the more important points have been brought to attention already. The RAF climb test has, in 2nd charger gear, produced the best climb rates that are around for any Fw 190A. In my opinion, there's a measurement/interpretation error. They are in fact getting a higher climb rate at altitude than at sea level, this simply is not within the possibilities of the design. You don't climb 5% faster at 15% less power.
Also, compared to a Spitfire Vb in a good condition, the climb rate of the Spitfire at max. climb setting is about as good as the emergency rating of the 190, so the report doesn't really reflect the truth.

Regarding the IX, the Merlin 61 and Merlin 63 models were still equipped with a float type carburettor, which would always have a few problems with negative g's. There were a couple of workarounds included, but the problem didn't disappear completely. The later Merlins, like the 66, did have an injection type carburettor, which did no longer cause any neg g troubles.

RegRag1977
06-10-2010, 12:57 PM
You're welcome JtD http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif

Kettenhunde
06-11-2010, 02:24 PM
The climbs were performed in that test on each engines maximum continuous rating.

Most of the Spitfire climb performance curves depict data at WEP.

You can look at the boost rating and see it is flown at the 5 min rating for the only climb depicted without a 30 gallon.

http://www.spitfireperformance.com/bf274.html

JtD
06-11-2010, 03:21 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Kettenhunde:
The climbs were performed in that test on each engines maximum continuous rating.

Most of the Spitfire climb performance curves depict data at WEP.

You can look at the boost rating and see it is flown at the 5 min rating for the only climb depicted without a 30 gallon.

http://www.spitfireperformance.com/bf274.html </div></BLOCKQUOTE>

Please check table I in the linked document.

Kettenhunde
06-11-2010, 06:19 PM
Do you understand that "most" does not mean the same as "all"?

The majority of climb data on the Merlin 61 Spitfire Mk IX is at a 5 minute limit WEP and not the climb rating.

As tested at the climb rating, their was little to choose. The math agrees with the RAE on the zoom climb performance with the Focke Wulf having the edge especially in the initial portion of the zoom climb.

Kettenhunde
06-11-2010, 06:24 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">The Spit has no reason look for a quick shot; it can just zoom up and make slight turn away from the Fw during zoom to keep it visible. And then just keep on climbing in shallow turn. Note that in the end of zoom, at 1600-1700m, it is allready couple hunred meters higher and above 2km it will be faster than Fw while distance is still well over 1000m despite what ever move the Fw tries. </div></BLOCKQUOTE>

http://forums.ubi.com/eve/foru...201021668#7201021668 (http://forums.ubi.com/eve/forums/a/tpc/f/23110283/m/8061010468?r=7201021668#7201021668)

This is not even close to correct. There is no way the Spitfire will end up a couple of hundred meters above the Focke Wulf in a zoom climb from Vmax to stall.

M_Gunz
06-11-2010, 08:59 PM
Above and behind when the FW zooms at a shallower angle and stalls first. Why so hard to realize that a rigged
test is supposed to come out with the desired results?

Wurkeri
06-11-2010, 11:09 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by M_Gunz:
Above and behind when the FW zooms at a shallower angle and stalls first. </div></BLOCKQUOTE>

The starting situation as originally discused was that the Fw allready had a 1500m lead. It was your argument that the Fw should use a zoom to get an altitude advantage despite the sustained climb adavantage of the Spit. What I pointed out to you is that zooming won't work in that situation because the Spit can zoom higher.

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by M_Gunz:
Why so hard to realize that a rigged test is supposed to come out with the desired results? </div></BLOCKQUOTE>

Where do you see a rigged test and what were the desired results?

Two years ago you got the Autopilot scripts, large part of the results on spreadsheets and much more information on these tests than ever posted on board. And now you talk about a rigged test for desired results http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif

Anyway, make your own tests if you are not happy with the rigging or the results. As said many times before; walk the walk instead talk the talk.

Note that this is not depending on plane type discused; I don't fly Spits nor Fw in this simulator. However, the Bf 109G-2 has pretty similar climb advantege over the La-5 as the LF.IX has over the A-8 so very similar tactics can be used in the similar situation despite the La and Fw are faster than their opponents at sealevel.

JtD
06-11-2010, 11:46 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Kettenhunde:
Do you understand that "most" does not mean the same as "all"? </div></BLOCKQUOTE>

Yes, I very well do. I also understand that "the only climb without a 30 gallon" tank "is flown at the 5 min rating" implies that there's no data for the 1 hour rating. But there is, you just missed it. I don't get why you have to turn even the most simple things into a discussion, really.

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">The majority of climb data on the Merlin 61 Spitfire Mk IX is at a 5 minute limit WEP and not the climb rating. </div></BLOCKQUOTE>

If you know more than that one climb test at 15 lb boost/3000rpm, please post a link or another way to attain it.

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">This is not even close to correct. There is no way the Spitfire will end up a couple of hundred meters above the Focke Wulf in a zoom climb from Vmax to stall. </div></BLOCKQUOTE>

You keep saying that. As I have pointed out already, you will need arguments. At the moment it's two simulations vs. nothing but your insistence. Just having the last word was something that counted in kindergarten.

M_Gunz
06-12-2010, 02:06 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Wurkeri:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by M_Gunz:
Why so hard to realize that a rigged test is supposed to come out with the desired results? </div></BLOCKQUOTE>

Where do you see a rigged test and what were the desired results? </div></BLOCKQUOTE>

From JtD's test where it became clear that the FW was running a shallower path from his graphs. He put the FW on that
path just to keep them both climbing at the same rate which was by his desire and viola he got the same 200m vertical
separation in the end!

I was very happy with all you sent but lost those files. I don't think much of comparing zoom tests with different time
lengths anyway as they are simply not directly comparable. Historic tests compared positions at time which are. In a
climb as shallow as 30 degrees you are getting factors besides energy becoming of major importance, slats planes and
those with lower wing loading benefit largely. It's not just zoom being tested there. Dive, transition, and zoom tests
combined just add more factors.
When I was looking at SEP by level acceleration I had to learn that I could not use a bumpy flight by simply working
out the PE change and adding to the KE change. Viper and Kett both made that clear, if you let both change then you
can't say what either is doing as the trade-offs are not linear nor immediate. A multitude of factors muddies the results,
the labels lose meaning as what you get is not what the labels say.

In combat you don't have one plane stop flying and hang in the air while the other flies on until it stalls. One will end
up higher, later, but the difference is no longer connected in any simple, direct way; certainly not as related energy
states. As unrelated energy states... sure thing there.

Every factor left out between test and results is meaning lost. The truth in differences in results is lost. The link
between start state and end state of each plane is broken when only the start and end states are considered. That is
why IRL flight tests are done under strict controls with only certain elements allowed to change, so you don't get one
change hiding in another else your results are no good. That is why I quit my attempts at finding SEP, my flight tests
were not good enough over the range I wanted to test. Hey, you were one of the people who let me know and you were right!

JtD
06-12-2010, 02:42 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">From JtD's test where it became clear that the FW was running a shallower path from his graphs. He put the FW on that path just to keep them both climbing at the same rate which was by his desire and viola he got the same 200m vertical separation in the end! </div></BLOCKQUOTE>

Ok, but how was that test rigged and how was the result desired?

But I would like to point out right away:
- Having the two planes climb at the same rate was the PREMISE of my (2nd) test, it did not "become clear" from the graphs.
- The objective of the test was to illustrate the change of energy height through a zoom climb at the same rate of climb, which is the same thing as speed retention. It makes a good direct comparison because the planes are at the same altitude all the time.
- Zooming at the same angle gives the same results, yet they are not as directly comparable, because the planes reach their altitude at different times.
- That the Spitfire ends up above the 190 is down to physics, not desire.

If you think there is a testing procedure that illustrates how the Spitfire can not match the 190's zoom climb in a full power climb from top speed, please either test it, or post it so I can do the test for you.

Wurkeri
06-12-2010, 03:17 AM
As far as my own test are concerned; I used the E_angle command with following tweakings in the autopilot.ini:

[E_Angle]
pGain=0.03
iGain=0.02
iLimits=1000
dGain=0.5
Spd000Mul=1
Spd100Mul=1
Spd200Mul=1
Spd300Mul=1
Spd400Mul=1
Spd500Mul=1
Spd600Mul=1
Spd700Mul=1
Spd800Mul=1
Spd900Mul=1
Spd1000Mul=1

I flew plane down to about 10m and accelerated to the given speeds before activating the AP; it's a bit faster this way and it takes some time to accelerate last few km/h. I tested 45deg angle and the script was:

W_RelTime&gt;2
A_Bank=0
R_Slip=0
C_WEP
T_Spd=2000
E_Angle=45

There is an undocumented command E_g for constant g pull but it appears to be difficult to adjust for short pullouts so I have not used it for testing.

M_Gunz
06-12-2010, 03:30 AM
- Having the two planes climb at the same rate was the PREMISE of my (2nd) test, it did not "become clear" from the graphs.

I missed that part somehow between the words zoom test and Spitfire zooms higher. I should have looked for the word fair.

It became clear to ME when second to second two planes are at the same height while at the same time one is much faster.
Before then it was not. Before was this silly idea that comparing zooms between planes they zoom on the same path angle.

But I was just being silly to think that end height was a matter of zoom and not when each will stall given that
height gain was carefully rigged to stay even -over time-. Of course with more -time- one will go higher!

That is why I was not surprised that distance covered, even to the stall points was not counted in the results as well.
The only thing that mattered was the ending height.

JtD
06-12-2010, 04:01 AM
What mattered to me is that the Spitfire started to gain in terms of energy height as soon as the zoom climb started, and kept on gaining throughout the maneuver. I am convinced that the 190 can zoom climb at any parameters it wants, the Spitfire will always be able to gain on it and, owing to the lower stall speed, eventually be able to end up above it. I cannot disprove my theory myself, because I wouldn't know a way. So, I'm asking you to set parameters for the 190 zoom climb, and I'll try to find parameters for the Spitfires zoom climb to counter it. If the Spitfire is the zoom climber I think it is, I always will.

Of course it is always possible to find a way where the Spitfire cannot match the performance required, for instance, one could dive it right into the ground. This way, the 190 will certainly end up above it.

M_Gunz
06-12-2010, 02:08 PM
The energy of moving the planes through the air besides raising the PE is still Work against Drag, yes?
You have constant energy input for both planes and what is the result you choose to label? I think that
is misleading whether intended or not and tried to show you the ways it is so.

A vertical zoom has no stall factor past any stall pulled in transition. The energy result is cleaner.
And surely to me the TE differences will get smaller as both planes slow down, P/W of the Spit being higher.
What will not be there is induced drag even at the very lowest speeds which can be run down to zero, will
the Spitfire still zoom longer though?

In a FW, one important maneuver is changing heading by rolling while going mostly or totally vertical.
You not only get the fastest change of heading but you get the largest change of height in the least time.
Of course you need to get out with enough speed to make use of the heading change, or in the case you are
heading down then out before you go too fast or too far. Either way is far less combat zone suicide than
letting the FW get slower than 320 kph let alone down to take-off speed.

If you are just trying to show that the IL2 Spit IX's are Ubered then what you have done so far goes a long
way. It's like a slice of Tagert's show to push claims against the 109K climb rates. It would be funny to
substitute the 109K-4 for that FW in your test even if you have to run the 109 a bit more shallow to match
the climb rates... I bet the 109 is still climbing after the Spitfire has stalled! Who is Uber then?

M_Gunz
06-12-2010, 02:09 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by JtD:
Of course it is always possible to find a way where the Spitfire cannot match the performance required, for instance, one could dive it right into the ground. This way, the 190 will certainly end up above it. </div></BLOCKQUOTE>

If they hit the same spot, the one that hits first will surly end up underneath? Just underneath.

M_Gunz
06-12-2010, 02:26 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Wurkeri:
As far as my own test are concerned; I used the E_angle command with following tweakings in the autopilot.ini:

[E_Angle]
pGain=0.03
iGain=0.02
iLimits=1000
dGain=0.5
Spd000Mul=1
Spd100Mul=1
Spd200Mul=1
Spd300Mul=1
Spd400Mul=1
Spd500Mul=1
Spd600Mul=1
Spd700Mul=1
Spd800Mul=1
Spd900Mul=1
Spd1000Mul=1

I flew plane down to about 10m and accelerated to the given speeds before activating the AP; it's a bit faster this way and it takes some time to accelerate last few km/h. I tested 45deg angle and the script was:

W_RelTime&gt;2
A_Bank=0
R_Slip=0
C_WEP
T_Spd=2000
E_Angle=45

There is an undocumented command E_g for constant g pull but it appears to be difficult to adjust for short pullouts so I have not used it for testing. </div></BLOCKQUOTE>

I think we can learn more from this including speed/height-change checks on flight path though IIRC Lesnihu uses
just that to determine E_Angle?

Still at 30 degree climb, IMO you are getting induced drag differences into the results.

Most problems I have are not so much with the tests as the labels and uses of the results, you understand?
Problem is that labels not only fail to convey much, they later get used as whole meanings to show unrelated
conclusions. This is true in business as well as engineering, perhaps even more true in business. I have
coded for both and believe me just about pulled hair over what errors get made.

Kettenhunde
06-12-2010, 02:59 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content"> At the moment it's two simulations vs. nothing but your insistence. </div></BLOCKQUOTE>


No, it is a game vs. the math used to determine the behavior of airplanes in the real world.

Like anything, there is a percentage variation in the math.

You remember your insistence using TAS to determine turn performance was the accurate and specific performance of an aircraft? It is not in fact.

Not without lots of measured data which you do not have.....

What will not change in these performance calculation methods within that percentage variation is the general performance trend.


For example, a Focke Wulf is just not capable of out performing the Spitfire at sustained level turns below the Focke Wulf best load factor speeds.

Just as the Spitfire is not capable of zooming 200 feet above the Focke Wulf from a Vmax zoom climb.

In the FW-190A8 vs Spitfire Mk IX Merlin 66 +18lbs from Vmax:

Characteristics of our Focke Wulf:

Zoom climb from 312KEAS mph to 94.4KEAS at a 45 degree angle:

312KEAS = 527.28fps
Zoom Angle 45 degrees
Vs = 94.4KEAS = 159.53 fps

Zoom height:

Sum the forces on the flight path -

*using excess thrust forces &lt;means thrust available has already been subtracted from thrust required&gt;

9418lbs * sin 45 = 6659.5bs
2362 lbs 6659.5lbs = -4297lbs

a = F/m

m = 9418lbs/32.2 = 292.5lb-s^2/ft
a= 4297lb/292.5lb-s^2/ft
a = 14.7 ft/s^2

s = (V1^2 V2^2 ) / 2a

s = (527.28^2 159.53^2)/(2 * 14.7 ft/s^2) = 8591 ft

8590 ft * sin 45 = 6074 ft


Characteristics of our Spitfire:

Zoom climb from 286.89 KEAS to 80KEAS at a 45 degree angle:

286.89KEAS = 485.1fps
Zoom Angle 45 degrees
Vs = 80 KEAS = 135.2fps

Zoom height:

Sum the forces on the flight path -

7450lbs * sin 45 = 5267lbs
2268lbs 5267lbs = 2998lbs

a = F/m

m = 7450lbs/32.2 = 231 lb-s^2/ft
a= 2998lb/231lb-s^2/ft
a = 12.97 ft/s^2

s = (V1^2 V2^2 ) / 2a

s = (485.1^2 135.2^2)/(2 * 12.97ft/s^2) = 8367 ft

8367 ft * sin 45 = 5916 ft

Using the 330 mph Spitfire data the RAE noted to be consistent and not optimistic, we find the Focke Wulf to be ~150 feet higher at the end of the zoom climb.

Within the realm of significant digits, the Focke Wulf outzooms the Spitfire.

If we use the Spitfire data the RAE noted as optimistic, we find the Spitfire ends up ~30 feet above the Focke Wulf.

30 feet is less than a wingspan. In the realm of significant digits, the airplanes are equal in zoom climb.

In a dogfight:


Characteristics of our Focke Wulf:

Zoom climb from 240KEAS mph to 94.4KEAS at a 45 degree angle:

240KEAS = 405.6fps
Zoom Angle 45 degrees
Vs = 94.4KEAS = 159.53 fps

Zoom height:

Sum the forces on the flight path -

9418lbs * sin 45 = 6659.5bs
2935.5 lbs 6659.5lbs = -3723lbs

a = F/m

m = 9418lbs/32.2 = 292.5lb-s^2/ft
a= 3723lb/292.5lb-s^2/ft
a = 12.7 ft/s^2

s = (V1^2 V2^2 ) / 2a

s = (405.6^2 159.53^2)/(2 * 12.7 ft/s^2) = 5475 ft

5475 ft * sin 45 = 3871 ft


Characteristics of our Spitfire:

Zoom climb from 149 KEAS to 80KEAS at a 45 degree angle:

149KEAS = 251.8 fps
Zoom Angle 45 degrees
Vs = 80 KEAS = 135.2fps

Zoom height:

Sum the forces on the flight path -

7450lbs * sin 45 = 5267lbs
3409.5lbs 5267lbs = 1857.5lbs

a = F/m

m = 7450lbs/32.2 = 231 lb-s^2/ft
a= 1857.5lb/231lb-s^2/ft
a = 8 ft/s^2

s = (V1^2 V2^2 ) / 2a

s = (251.8^2 135.2^2)/(2 * 8 ft/s^2) = 2820 ft

2820 ft * sin 45 = 1994 ft

In a zoom from the Spitfire best turn rate to stall speed, with the Focke Wulf at best load factor to stall speed, the FW-190 ends up 1877 feet above the Spitfire.

That is how the physical world works.

http://img16.imageshack.us/img16/709/fockewulfvsspitfire.jpg (http://img16.imageshack.us/i/fockewulfvsspitfire.jpg/)

http://img204.imageshack.us/img204/7937/fwvsspitfireloadfactor.jpg (http://img204.imageshack.us/i/fwvsspitfireloadfactor.jpg/)

JtD
06-12-2010, 03:17 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by M_Gunz:
The energy of moving the planes through the air besides raising the PE is still Work against Drag, yes?
You have constant energy input for both planes and what is the result you choose to label? I think that is misleading whether intended or not and tried to show you the ways it is so. </div></BLOCKQUOTE>

What? Didn't get that. What is which result who applied what label to and where's the problem?

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">A vertical zoom has no stall factor past any stall pulled in transition. The energy result is cleaner.
And surely to me the TE differences will get smaller as both planes slow down, P/W of the Spit being higher.
What will not be there is induced drag even at the very lowest speeds which can be run down to zero, will the Spitfire still zoom longer though? </div></BLOCKQUOTE>

Yes, because in the pullup into the vertical climb the Fw loses a lot more speed than the Spitfire.

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">If you are just trying to show that the IL2 Spit IX's are Ubered then what you have done so far goes a long way. It's like a slice of Tagert's show to push claims against the 109K climb rates. It would be funny to substitute the 109K-4 for that FW in your test even if you have to run the 109 a bit more shallow to match the climb rates... I bet the 109 is still climbing after the Spitfire has stalled! Who is Uber then? </div></BLOCKQUOTE>

Is that directed at me or someone else?

JtD
06-12-2010, 03:18 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Kettenhunde:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content"> At the moment it's two simulations vs. nothing but your insistence. </div></BLOCKQUOTE>


No, it is a game vs. the math used to determine the behavior of airplanes in the real world. </div></BLOCKQUOTE>

If you insist... http://forums.ubi.com/groupee_common/emoticons/icon_rolleyes.gif

Kettenhunde
06-12-2010, 03:55 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">And surely to me the TE differences will get smaller as both planes slow down, P/W of the Spit being higher. </div></BLOCKQUOTE>

Yes they do get smaller and the Spitfire moves to superiority.

If you use TE concepts the Spitfire has much more potential to maneuver at lower velocity.

The fantasy some want to believe is the excess power curve does not exist and that the laws of physics will change so that the Spitfire is superior at all altitudes and all speeds.

M_Gunz
06-12-2010, 04:22 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Kettenhunde:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">And surely to me the TE differences will get smaller as both planes slow down, P/W of the Spit being higher. </div></BLOCKQUOTE>

Yes they do get smaller and the Spitfire moves to superiority.

If you use TE concepts the Spitfire has much more potential to maneuver at lower velocity.

The fantasy some want to believe is the excess power curve does not exist and that the laws of physics will change so that the Spitfire is superior at all altitudes and all speeds. </div></BLOCKQUOTE>

That's the thing about labels and results and forgetting or never knowing how the results were obtained when applying them.

BTW in your calculations above, how did you come up with the average T-D values? I can see how thrust would increase even as
drag decreases all the way up but I haven't done that kind of calculus in over 20 years now. Would a stepwise method done in
code be close enough, perhaps taking very short interval averages and summing results. All in TAS of course!

M_Gunz
06-12-2010, 04:29 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by JtD:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">If you are just trying to show that the IL2 Spit IX's are Ubered then what you have done so far goes a long way. It's like a slice of Tagert's show to push claims against the 109K climb rates. It would be funny to substitute the 109K-4 for that FW in your test even if you have to run the 109 a bit more shallow to match the climb rates... I bet the 109 is still climbing after the Spitfire has stalled! Who is Uber then? </div></BLOCKQUOTE>

Is that directed at me or someone else? </div></BLOCKQUOTE>

IIRC in this thread we have more than once, maybe more than twice seen the zoom test conclusions as basis for
how clear it is the Spits are overmodeled. I forget if it was you who stated the Spits are probably not, that
the 190A-8 looks undermodeled, but one person did.

The tests are cool. Data to the people! It's the conclusions and uses of I keep feeling unhappy with. With you
and your test runs I think I made it clear that I believe that looking at end heights alone while calling it a
zoom test is misleading.

Kettenhunde
06-12-2010, 06:47 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">BTW in your calculations above, how did you come up with the average T-D values? </div></BLOCKQUOTE>


I sent you a PM.

M_Gunz
06-12-2010, 07:02 PM
Sorry, I forgot about that.

Wurkeri
06-12-2010, 11:02 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by M_Gunz:
I think we can learn more from this including speed/height-change checks on flight path though IIRC Lesnihu uses just that to determine E_Angle?

Still at 30 degree climb, IMO you are getting induced drag differences into the results. </div></BLOCKQUOTE>

The only reason I talk about testing here is your claim that people are making rigged tests for the desired results; with these autopilot settings you can duplicate my test and modify the test if in doubt (higher angle of the zoom or what ever).

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by M_Gunz:
Most problems I have are not so much with the tests as the labels and uses of the results, you understand? Problem is that labels not only fail to convey much, they later get used as whole meanings to show unrelated conclusions. This is true in business as well as engineering, perhaps even more true in business. I havecoded for both and believe me just about pulled hair over what errors get made. </div></BLOCKQUOTE>

Given the original problem (1500m separation etc.) I see my testing relevant and conclusions valid.

However, I don't know where is this discussion heading. Originally I saw only that people were making stupid suggestions to fight against a better climbing (sustained and zoom) aircraft. The types discused do not really matter; if I fly La-5, I don't enter to the game of the Bf 109G-2 which can do any climbing maneuver better than the La-5 just like the LF.IX has a similar advantage over the A-8.

JtD
06-12-2010, 11:30 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by M_Gunz:
...With you and your test runs I think I made it clear that I believe that looking at end heights alone while calling it a zoom test is misleading. </div></BLOCKQUOTE>

This is why I provided 6 charts with different quantities shown as a function of time. It gives you a lot more info than just end height. But the bottom line of that zoom climb test is that the Spitfire outzooms the 190. So far, no one has come up with an in game test showing otherwise.

And no, it wasn't me who think the Spitfire is modeled to generously, I keep saying that if anything it is lacking in climb.

M_Gunz
06-12-2010, 11:36 PM
I don't think that a slower moving Spitfire will out-zoom a faster moving 190A-8, especially in the short term and
especially in a vertical zoom. The FW however must be flown with finesse to keep the most speed in the nosing up
process. I've noted since 2002 that many players are simply unable to do that whether in transition or turn. They
do not establish the turn or pitching moment and then follow it along, they just yank the stick and whine about
speed bleed. I noted that because I did not have the same experience at all. Spitfire can take more abrupt stick
use with less bleed than FW but they and any other plane also benefit from better, smoother, handling.

JtD
06-13-2010, 01:04 AM
I'd say it's obvious that the faster plane in a vertical climb has a better rate of climb. So, yes, if you want to pick a small fraction of a maneuver and base your evaluation on that, it is possible that the 190 outzooms the Spitfire. Personally, I consider temporary gains of that magnitude irrelevant in that situation.

And for what it's worth, in game in a (near) vertical climb both of them end up at about equal altitude, with the 190 maintaining a small advantage down to very a low speed. Maximum advantage gained was ~100m. I don't see how the 190 could exit that zoom climb while maintaining the advantage, though. Also, in terms of Eh, the advantage has gotten smaller when compared to the initial sea level figures.

JtD
06-13-2010, 01:06 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Kettenhunde:

The fantasy some want to believe is the excess power curve does not exist and that the laws of physics will change so that the Spitfire is superior at all altitudes and all speeds. </div></BLOCKQUOTE>

http://forums.ubi.com/images/smilies/partyhat.gif
Your statement was that the faster plane will always zoom higher. No one stated that the Spitfire zooms higher at all altitudes and all speeds. Stop posting nonsense.

Where's your updated calculation?

FatCat_99
06-13-2010, 02:53 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Kettenhunde:
No, it is a game vs. the math used to determine the behavior of airplanes in the real world.
</div></BLOCKQUOTE>
Just out of the curiosity, how do you imagine simulations work? How is position of the plane determined and rendered on the screen?
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">
That is how the physical world works.
</div></BLOCKQUOTE>
You said the same last time you made this calculation and than couple of posts later you said that there is a big error in the calculation. Is it correct to conclude that there is an error in physics world?

PS How can somebody with college education use EAS for flight path calculation? E.G. your plane fly vertically with constant speed of 100 m/s EAS , after 10 seconds it is at X m. Initial alt was 0 m.
What is the value of X,
a)1000m
b)less than 1000m
c)more than 1000m

BTW rectilinear equations are elementary school 8th grade material.

FC

Kettenhunde
06-13-2010, 05:59 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">PS How can somebody with college education use EAS for flight path calculation? </div></BLOCKQUOTE>

Ask David F Rogers....

http://img35.imageshack.us/img35/5828/easinturn.jpg (http://img35.imageshack.us/i/easinturn.jpg/)


http://www.nar-associates.com/...nalt_wide_screen.pdf (http://www.nar-associates.com/technical-flying/turning/turnalt_wide_screen.pdf)


Another firm using EAS for climb performance....

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content"> Climb at EAS </div></BLOCKQUOTE>

http://www.darcorp.com/Software/app/

EAS is commonly used in climb performance determination:

http://img709.imageshack.us/img709/8834/easinaclimb.jpg (http://img709.imageshack.us/i/easinaclimb.jpg/)

http://img641.imageshack.us/img641/2439/easinaclimbagain.jpg (http://img641.imageshack.us/i/easinaclimbagain.jpg/)


The question is how can anyone understand aircraft performance who has such trouble with the concepts as well as uses of relative performance, parametric study, or the uses of different airspeed?

I also do not understand how someone can claim to have performed higher order calculations cannot recognize the methods used to solve the vectors.

Maybe another hour in the library?

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content"> Is it correct to conclude that there is an error in physics world? </div></BLOCKQUOTE>

Yes it is....

It is relative performance we are concerned with.

In terms of relative performance, the Spitfire should not be 200 feet &lt;a very large margin&gt; above the Focke Wulf from a Vmax zoom climb to stall in the physical world.

I could care less what it does in a game. That is your realm. If you are happy with it then enjoy it, Fatcat.

Kettenhunde
06-13-2010, 06:21 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content"> Q When are results shown in equivalent airspeed (EAS) and when in true airspeed (TAS)?

A Horizontal speed (V) and vertical speed (W) can be both shown either as EAS or as TAS by setting the V equivalent and W equivalent parameters on the main sheet to Yes for EAS or No for TAS. </div></BLOCKQUOTE>

http://www.trimill.com/CuSoft/index.htm

That EAS is evil and does not return valid results!

Baloney...

You guys have never been exposed to it is all.

JtD
06-13-2010, 06:46 AM
Please don't just parrot things, try to apply them. The problem were flight path calculations, not bank angles, thrust, drag or climb performance.

Also, you failed to answer the question. Is it a), b) or c)?

And where's the updated calculation?

It's also interesting to see that you're right and the real world is wrong! Talk about self-confidence!

Kettenhunde
06-13-2010, 07:10 AM
The relative performance is not going to change with the application of an environmental effect equally applied to both aircraft at all speeds.

We went through pages of this and you still did not get it.

Maybe it would help your understanding if you thought of EAS as IAS. That is an accepted assumption in aircraft performance calculations.

badatflyski
06-13-2010, 07:16 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Kettenhunde:

It is absolute fantasy for your games Spitfire to end up 200 feet above the Focke Wulf as per Wurkeri's original claim.

That is not how the physical world works.
</div></BLOCKQUOTE>

That's because , in this game, the spit has a better energy retention coeffiecient (Kmax)than the 190 and also, because the spits in the game have a better Cx ( http://forums.ubi.com/images/smilies/88.gif ) and a less agressive Cx curve than the 190.( re- http://forums.ubi.com/images/smilies/88.gif )

Now, add tho that that the FM's have been altered by some spit maniac, you end with a 190 not beeing able to fly without cooling flaps open (normal proceudre in climb pressure) (adding more drag in the game calculations)and overheating after30sec in notleistung.

The game is so wrong with all the planes, it would take ages to modify each plane model and submodels to their real life caracteristics.

Have fun: Bada http://forums.ubi.com/images/smilies/16x16_smiley-very-happy.gif

Kettenhunde
06-13-2010, 07:42 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">spit has a better energy retention coeffiecient </div></BLOCKQUOTE>


What is an energy retention coefficienct??

You can't be serious on this, right? Does IL2 have this??

At cruise condition, the cooling gills are closed in a FW-190A8 unless conditions are hotter than standard.

Here is what the POH says about the cooling gill operation:

http://img163.imageshack.us/img163/9894/coolinggills.jpg (http://img163.imageshack.us/i/coolinggills.jpg/)

Why would your simulation have anything different?

JtD
06-13-2010, 07:54 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Kettenhunde:
The relative performance is not going to change with the application of an environmental effect equally applied to both aircraft at all speeds. </div></BLOCKQUOTE>

When calculating the real physics, and that is TAS, a plane going 200m/s at any altitude has the same energy altitude as one going at 50m/s 1910m above it. It's relative. And it doesn't work in EAS. And it's what you did when you were starting and ending your zoom climb estimates in EAS.

Oh, speaking of it, where's the updated calculation?

Holtzauge
06-13-2010, 08:41 AM
Previously posted Il2 data from JtD:

"Zoom altitude for A-8 from 580 km/h on the deck in a 30 zoom climb: 1500m. End speed: 200 km/h.
Zoom altitude for SpitIX from 540 km/h on the deck in a 30 zoom climb: 1700m. End speed: 160 km/h."

C++ simulations with same conditions:

http://img.photobucket.com/albums/v210/Holtzauge/CpropandjetPA31Spitfiremk9andFw190A.jpg

Also, I did some complementary tests and if the climb angle is changed then at 35 degree climb the Spit reaches 1.64 Km and the Fw190 1.4 Km.

If the 1.42 ata power data for the Fw190 is multiplied by 1.15 (i.e giving 2070 hp at SL) to simulate 1.65 ata then it tops out at 1.59 Km for the 30 degree climb case.

So overall a quite good correlation between the C++ simulations and Il2 and a totally different outcome than from Kettenhunde's deranged calculations showing a reversed result.

This thing of assuming constant acceleration for dynamic conditions is probably something Kettenhunde learned as a part of his "advanced degree" MSc aeronautical education. http://forums.ubi.com/images/smilies/88.gif

Finally, judging by results, it seems that the inrectumlinear equations that Kettenhunde uses are better suited for calculating bowel movements, not flight paths.

Kettenhunde
06-13-2010, 09:51 AM
The equation, the assumption, accuracy, and the answer is hardly unfamiliar to anyone who took this in college.

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content"> Question 2
The aircraft performs a quasi-rectilinear, symmetric climbing flight in Standard Atmosphere, with constant equivalent airspeed. </div></BLOCKQUOTE>

http://130.161.164.185/oude_te...070329%20%5BE%5D.pdf (http://130.161.164.185/oude_tentamens/2e%20jaar/AE2-202-1%20Performance%202/AE2-202-1%20070329%20%5BE%5D.pdf)

The fact it is so alien to some is telling.

Holtzauge
06-13-2010, 10:10 AM
No, what is telling is that you refer to a question that has no bearing whatsoever on what is going on. Question 2 refers to EAS being constant in a climb. The speed in the zooms we are discussing here are as far from constant EAS as they can be.

Also note that you are supposed to use quasi-rectilinear equations to solve question 2, not the quasi-inrectumlinear equations you are so fond of using http://forums.ubi.com/groupee_common/emoticons/icon_wink.gif

I guess you missed that as well.

M_Gunz
06-13-2010, 10:20 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by JtD:
I'd say it's obvious that the faster plane in a vertical climb has a better rate of climb. So, yes, if you want to pick a small fraction of a maneuver and base your evaluation on that, </div></BLOCKQUOTE>

Small fraction? And try looking at positions rather than rates. Even with FW flying a lower zoom angle you own graph showing
Eh has the Spitfire not matching until near the end.

Holtzauge
06-13-2010, 10:22 AM
BTW, Kettenhunde, as you see I have removed you from my ignore list. In the end, after much deliberation, I came to the conclusion that the entertainment value of your posts is so high that it outweighs the grief of seeing aeronautics and flight mechanics so brutally raped. http://forums.ubi.com/images/smilies/16x16_smiley-wink.gif

Holtzauge
06-13-2010, 11:29 AM
Another thing Kettenhunde: Since you have a clear picture about how the zoom performance should be what is your take on a BnZ like this one:

Fw190 A8 and Spitfire Mk9 dive and zoom poll (http://forums.ubi.com/eve/forums/a/tpc/f/23110283/m/5141034768)

Seeing your level of confidence concerning zoom performance above I would assume it would be a cinc to describe what would happen in this BnZ scenario?

Or maybe you just don't have a clue?

Kettenhunde
06-13-2010, 03:56 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Eh has the Spitfire not matching until near the end. </div></BLOCKQUOTE>


Which is also backed up by aircraft performance calculations.

That is two systems used to determine relative performance of real airplanes that give good agreement.

In the FW-190A8 vs Spitfire Mk IX Merlin 66 +18lbs from Vmax:

Characteristics of our Focke Wulf:

Zoom climb from 312KEAS mph to 94.4KEAS at a 45 degree angle:

312KEAS = 527.28fps
Zoom Angle 45 degrees
Vs = 94.4KEAS = 159.53 fps

Zoom height:

Sum the forces on the flight path -

*using excess thrust forces &lt;means thrust available has already been subtracted from thrust required&gt;

9418lbs * sin 45 = 6659.5bs
2362 lbs 6659.5lbs = -4297lbs

a = F/m

m = 9418lbs/32.2 = 292.5lb-s^2/ft
a= 4297lb/292.5lb-s^2/ft
a = 14.7 ft/s^2

s = (V1^2 V2^2 ) / 2a

s = (527.28^2 159.53^2)/(2 * 14.7 ft/s^2) = 8591 ft

8590 ft * sin 45 = 6074 ft


Characteristics of our Spitfire:

Zoom climb from 286.89 KEAS to 80KEAS at a 45 degree angle:

286.89KEAS = 485.1fps
Zoom Angle 45 degrees
Vs = 80 KEAS = 135.2fps

Zoom height:

Sum the forces on the flight path -

7450lbs * sin 45 = 5267lbs
2268lbs 5267lbs = 2998lbs

a = F/m

m = 7450lbs/32.2 = 231 lb-s^2/ft
a= 2998lb/231lb-s^2/ft
a = 12.97 ft/s^2

s = (V1^2 V2^2 ) / 2a

s = (485.1^2 135.2^2)/(2 * 12.97ft/s^2) = 8367 ft

8367 ft * sin 45 = 5916 ft

Using the 330 mph Spitfire data the RAE noted to be consistent and not optimistic, we find the Focke Wulf to be ~150 feet higher at the end of the zoom climb.

Within the realm of significant digits, the Focke Wulf outzooms the Spitfire.

If we use the Spitfire data the RAE noted as optimistic, we find the Spitfire ends up ~30 feet above the Focke Wulf.

30 feet is less than a wingspan. In the realm of significant digits, the airplanes are equal in zoom climb.

In a dogfight:


Characteristics of our Focke Wulf:

Zoom climb from 240KEAS mph to 94.4KEAS at a 45 degree angle:

240KEAS = 405.6fps
Zoom Angle 45 degrees
Vs = 94.4KEAS = 159.53 fps

Zoom height:

Sum the forces on the flight path -

9418lbs * sin 45 = 6659.5bs
2935.5 lbs 6659.5lbs = -3723lbs

a = F/m

m = 9418lbs/32.2 = 292.5lb-s^2/ft
a= 3723lb/292.5lb-s^2/ft
a = 12.7 ft/s^2

s = (V1^2 V2^2 ) / 2a

s = (405.6^2 159.53^2)/(2 * 12.7 ft/s^2) = 5475 ft

5475 ft * sin 45 = 3871 ft


Characteristics of our Spitfire:

Zoom climb from 149 KEAS to 80KEAS at a 45 degree angle:

149KEAS = 251.8 fps
Zoom Angle 45 degrees
Vs = 80 KEAS = 135.2fps

Zoom height:

Sum the forces on the flight path -

7450lbs * sin 45 = 5267lbs
3409.5lbs 5267lbs = 1857.5lbs

a = F/m

m = 7450lbs/32.2 = 231 lb-s^2/ft
a= 1857.5lb/231lb-s^2/ft
a = 8 ft/s^2

s = (V1^2 V2^2 ) / 2a

s = (251.8^2 135.2^2)/(2 * 8 ft/s^2) = 2820 ft

2820 ft * sin 45 = 1994 ft

In a zoom from the Spitfire best turn rate to stall speed, with the Focke Wulf at best load factor to stall speed, the FW-190 ends up 1877 feet above the Spitfire.

That is how the physical world works.

http://img163.imageshack.us/img163/7937/fwvsspitfireloadfactor.jpg (http://img163.imageshack.us/i/fwvsspitfireloadfactor.jpg/)

http://img693.imageshack.us/img693/4290/mustangvsfwrateofturn.jpg (http://img693.imageshack.us/i/mustangvsfwrateofturn.jpg/)

trashcanUK
06-13-2010, 05:04 PM
More sloppy mathematics Kettenhunde http://forums.ubi.com/groupee_common/emoticons/icon_frown.gif

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">7450lbs * sin 45 = 5267lbs </div></BLOCKQUOTE>
No = 5267.9455 = 5268 to 0 decimal places http://forums.ubi.com/groupee_common/emoticons/icon_wink.gif

But you are getting closer with the your Sin calculations and that is good http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif
Mixing 0,1 and 2 decimal places in your calculations may lead to compounded errors btw.
However you are showing signs of improvement.
Understand?

Kettenhunde
06-13-2010, 06:30 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">More sloppy mathematics Kettenhunde </div></BLOCKQUOTE>


http://forums.ubi.com/images/smilies/16x16_smiley-very-happy.gif

Kettenhunde
06-13-2010, 07:05 PM
I ran a C++++++++ simulation. You know the results agree with the game and other "simulations".

I think the issue is resolved.

http://img820.imageshack.us/img820/6504/csimulation.jpg (http://img820.imageshack.us/i/csimulation.jpg/)


Much more convincing evidence than the raw math laid out for everyone to see and terms most people can easily understand from two accepted methods of determining aircraft performance.

Case closed...

M_Gunz
06-13-2010, 08:50 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by trashcanUK:
Mixing 0,1 and 2 decimal places in your calculations may lead to compounded errors btw. </div></BLOCKQUOTE>

I see how you got trashcan. But in the UK shouldn't that be trashbin?

Science Math clue for you: count the significant digits.

irR4tiOn4L
06-13-2010, 09:40 PM
If i were you Kettenhunde, i would delete that last post because it is clearly in frustration and it detracts from your other ones.

I would focus on that energy retention coefficient Bada posted - and why he thinks IL2's flight models are off. A very important but unanswered question was how IL2 calculates these results.

I would resolve the zoom situation as rapidly as possible, for better or worse - it seems to me that some misunderstandings are taking place

You seem to be calculating a vertical zoom with no thrust or drag (thrust reduced to match drag) without stall speed being a factor, to reach maximum height. However, even with that approach your figures have been shown, depending on assumptions about fuel load and maximum speed, to vary between either aircraft zooming higher. Even if your figures are right, it is clear zooming is very sensitive to assumptions changing (as might happen, for example, in the pull up into a zoom)

What some are arguing against you, is that your calculation is not a realistic zoom scenario, and in a real zoom the greater climb rate and constant max power being applied in both aircraft, combined with the lower stall speed of the spit and the higher energy loss the FW suffers in the pull up - mean that in a REAL zoom, the spit can actually outzoom the FW due to the latter's inability to translate its higher speed into a higher zoom as efficiently.

That is a fairly reasonable argument and if i were you, id take a look at it and wind that argument up, moving on to what 'kmax' is in IL2. Because as far as i can see, both your calculation and the C++ models used are correct of themselves, but it is their relevance to actual zoom climbs that is significant

JtD
06-13-2010, 10:40 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">That is how the physical world works. </div></BLOCKQUOTE>

14.7 s sustained turn time for the Spitfire. How reassuring!

JtD
06-14-2010, 12:16 AM
Thanks for posting the updated calculation, sadly there's only little improvement. That's why several comments had to be repeated.

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Kettenhunde: <span class="ev_code_RED">Comments by JtD</span>

In the FW-190A8 vs Spitfire Mk IX Merlin 66 +18lbs from Vmax:

Characteristics of our Focke Wulf:

Zoom climb from 312KEAS mph to 94.4KEAS at a 45 degree angle: <span class="ev_code_RED">calculation needs to be done in TAS, remove mph, clarify stall speed, stall speed in relation to Spitfire wrong</span>

312KEAS = 527.28fps
Zoom Angle 45 degrees
Vs = 94.4KEAS = 159.53 fps

Zoom height:

Sum the forces on the flight path -

*using excess thrust forces &lt;means thrust available has already been subtracted from thrust required&gt; <span class="ev_code_RED">Thrust calculation needs to be shown for assessment of correctness, see below.</span>

9418lbs * sin 45 = 6659.5bs
2362 lbs 6659.5lbs = -4297lbs

a = F/m

m = 9418lbs/32.2 = 292.5lb-s^2/ft
a= 4297lb/292.5lb-s^2/ft
a = 14.7 ft/s^2 <span class="ev_code_RED">linear approach wrong</span>

s = (V1^2 V2^2 ) / 2a

s = (527.28^2 159.53^2)/(2 * 14.7 ft/s^2) = 8591 ft <span class="ev_code_RED">linear approach wrong</span>

8590 ft * sin 45 = 6074 ft


Characteristics of our Spitfire:

Zoom climb from 286.89 KEAS to 80KEAS at a 45 degree angle: <span class="ev_code_RED">use TAS, clarify stall speed, stall speed in relation to Fw wrong</span>

286.89KEAS = 485.1fps
Zoom Angle 45 degrees
Vs = 80 KEAS = 135.2fps

Zoom height:

Sum the forces on the flight path -

7450lbs * sin 45 = 5267lbs
2268lbs 5267lbs = 2998lbs

a = F/m

m = 7450lbs/32.2 = 231 lb-s^2/ft
a= 2998lb/231lb-s^2/ft
a = 12.97 ft/s^2 <span class="ev_code_RED">linear approach wrong</span>

s = (V1^2 V2^2 ) / 2a

s = (485.1^2 135.2^2)/(2 * 12.97ft/s^2) = 8367 ft <span class="ev_code_RED">linear approach wrong</span>

8367 ft * sin 45 = 5916 ft

Using the 330 mph Spitfire data the RAE noted to be consistent and not optimistic, we find the Focke Wulf to be ~150 feet higher at the end of the zoom climb. <span class="ev_code_RED">wrong assessment of historical fact, missing discussion on Fw data</span>

Within the realm of significant digits, the Focke Wulf outzooms the Spitfire.

If we use the Spitfire data the RAE noted as optimistic, we find the Spitfire ends up ~30 feet above the Focke Wulf. <span class="ev_code_RED">wrong assessment of historical fact, missing discussion on Fw data</span>

30 feet is less than a wingspan. In the realm of significant digits, the airplanes are equal in zoom climb.

In a dogfight: <span class="ev_code_RED">should read: In a situation chosen by the author</span>


Characteristics of our Focke Wulf:

Zoom climb from 240KEAS mph to 94.4KEAS at a 45 degree angle: <span class="ev_code_RED">use TAS, remove mph, clarify stall speed, stall speed in relation to Spitfire wrong</span>

240KEAS = 405.6fps
Zoom Angle 45 degrees
Vs = 94.4KEAS = 159.53 fps

Zoom height:

Sum the forces on the flight path -

9418lbs * sin 45 = 6659.5bs
2935.5 lbs 6659.5lbs = -3723lbs

a = F/m

m = 9418lbs/32.2 = 292.5lb-s^2/ft
a= 3723lb/292.5lb-s^2/ft
a = 12.7 ft/s^2 <span class="ev_code_RED">linear approach wrong</span>

s = (V1^2 V2^2 ) / 2a

s = (405.6^2 159.53^2)/(2 * 12.7 ft/s^2) = 5475 ft <span class="ev_code_RED">linear approach wrong</span>

5475 ft * sin 45 = 3871 ft


Characteristics of our Spitfire:

Zoom climb from 149 KEAS to 80KEAS at a 45 degree angle: <span class="ev_code_RED">use TAS, clarify stall speed, stall speed in relation to Fw wrong</span>

149KEAS = 251.8 fps
Zoom Angle 45 degrees
Vs = 80 KEAS = 135.2fps

Zoom height:

Sum the forces on the flight path -

7450lbs * sin 45 = 5267lbs
3409.5lbs 5267lbs = 1857.5lbs <span class="ev_code_RED">Excess thrust wrong, Spitfire cannot maintain a 27 climb at the speeds in question as the calculation suggests.</span>

a = F/m

m = 7450lbs/32.2 = 231 lb-s^2/ft
a= 1857.5lb/231lb-s^2/ft
a = 8 ft/s^2 <span class="ev_code_RED">linear approach wrong</span>

s = (V1^2 V2^2 ) / 2a

s = (251.8^2 135.2^2)/(2 * 8 ft/s^2) = 2820 ft <span class="ev_code_RED">linear approach wrong</span>

2820 ft * sin 45 = 1994 ft

In a zoom from the Spitfire best turn rate to stall speed, with the Focke Wulf at best load factor to stall speed, the FW-190 ends up 1877 feet above the Spitfire. <span class="ev_code_RED">Takes the Fw 5 seconds longer.</span>

That is how the physical world works. <span class="ev_code_RED">The physical world does not work in linear approximations.</span> </div></BLOCKQUOTE>

FatCat_99
06-14-2010, 02:35 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Kettenhunde:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">PS How can somebody with college education use EAS for flight path calculation? </div></BLOCKQUOTE>
Ask David F Rogers....
</div></BLOCKQUOTE>

I could but why, he is not the one who is using EAS to calculate distance.

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">
Another firm using EAS for climb performance....
</div></BLOCKQUOTE>
And your point is what exactly? Nobody said that EAS don't have its place in aerodynamics problem is that you don't know where and why to use it.
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">
The question is how can anyone understand aircraft performance who has such trouble with the concepts as well as uses of relative performance, parametric study, or the uses of different airspeed? </div></BLOCKQUOTE>
That's exactly what I would like to know.
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">
I also do not understand how someone can claim to have performed higher order calculations cannot recognize the methods used to solve the vectors.

Maybe another hour in the library?
</div></BLOCKQUOTE>
Unlike you I had physics in elementary,high school and in college. Rectilinear equations of motions are taught in 8th grade of elementary school and I do know why you can't use EAS to calculate distance.

Another "trick" question regarding EAS, which plane is faster, plane X with max. speed 500kmh EAS or plane Y with max. speed 500 kmh EAS?

And if both planes fly from A to B at their max. speeds which one will come to B faster. http://forums.ubi.com/groupee_common/emoticons/icon_cool.gif

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">
I could care less what it does in a game. That is your realm. If you are happy with it then enjoy it, Fatcat. </div></BLOCKQUOTE>
I certainly enjoy it and as any other PC flight sim it is simplified here and there but even with its simplifications it is way more complex and precise than your calculations.

M_Gunz
06-14-2010, 02:36 AM
Converting KEAS to fps and using that is not TAS? TAS must be SI?
Of course the bottom of the zoom at SL you can convert EAS to TAS but what about the top at some yet-to-be-determined height?

How do you calculate stall speed for a constant angle zoom? Would that be 1G stall x cosine of zoom angle?

tmp190
06-14-2010, 06:35 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by JtD:
<span class="ev_code_RED">linear approach wrong</span>
</div></BLOCKQUOTE>

By this you mean the same I was thinking ?:
Excess thrust varies with speed (and altitude, even the power is not strictly constant), therefore the closed form calculation is inaccurate.

One should use step by step calculation with small time increments, calculating T-D in each step separately, and finally summing the total distance/height.

tmp190
06-14-2010, 06:53 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by M_Gunz:
How do you calculate stall speed for a constant angle zoom? Would that be 1G stall x cosine of zoom angle? </div></BLOCKQUOTE>

As lift is proportional to speed^2, stall speed is proportional to square root of (1 G stall speed x cosine (angle))

M_Gunz
06-14-2010, 08:11 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by tmp190:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by JtD:
<span class="ev_code_RED">linear approach wrong</span>
</div></BLOCKQUOTE>

By this you mean the same I was thinking ?:
Excess thrust varies with speed (and altitude, even the power is not strictly constant), therefore the closed form calculation is inaccurate.

One should use step by step calculation with small time increments, calculating T-D in each step separately, and finally summing the total distance/height. </div></BLOCKQUOTE>

Perhaps you should ask him how he arrived at the figure he did. I did and even got an answer.
How correct it is, I dunno, but I could probably use the same method in increments to see if it changes in any trend.
Last time I did anything like that and presented it here though, I got zero replies so why waste my time?

M_Gunz
06-14-2010, 08:15 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by tmp190:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by M_Gunz:
How do you calculate stall speed for a constant angle zoom? Would that be 1G stall x cosine of zoom angle? </div></BLOCKQUOTE>

As lift is proportional to speed^2, stall speed is proportional to square root of (1 G stall speed x cosine (angle)) </div></BLOCKQUOTE>

Interesting. I've been writing for years now about gravity assist in going into the vertical without really
checking into that part of the math. I knew the need for lift would be less, but it is less that I thought!

Thank You!

JtD
06-14-2010, 08:55 AM
M_Gunz, converting KEAS to fps is not converting it to TAS, no. You're right that at sea level they are one and the same and that you'd have to do the conversion as you go up to eventually the yet-to-be-determined altitude. In this particular case the error in stall speeds is rather small, in particular considering the other oddities involved, and in the region of &lt;10%. You'd have to do some kind of iteration to address the effects. Eventually it is a matter of principle that proper calculations of this kind have to be done in TAS, energy, or energy height, doesn't come in equivalent air speed quantities. EAS Joule do not exist.

tmp190, yes, the linear approximation over the entire maneuver is very inaccurate. It could be used very accurately in a step by step approximation as you describe, given the time increments are small enough. At some point one has to account for the variable deceleration, owing to the varying excess thrust, as you said.

Kettenhunde
06-14-2010, 10:13 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">How do you calculate stall speed for a constant angle zoom? </div></BLOCKQUOTE>

That path of the airplane is not rectilinear.

We treat the vector the airplane travels as rectilinear motion. That vector becomes our rigid frame of reference for which our omega or moving frame of reference &lt;airplane&gt; changes specific position.

We are solving for the distance traveled along the principle axis, X, and Z.

http://www.youtube.com/watch#!...VqQI&feature=related (http://www.youtube.com/watch#!v=UpSMNYTVqQI&feature=related)

http://www.youtube.com/watch#!...w6J0&feature=related (http://www.youtube.com/watch#!v=4zSY07bw6J0&feature=related)

What is being done is the forces along the vector are resolved and then we can calculate the distance traveled along that vector or rigid frame of reference.


If we want the actual flight path of the aircraft can then be calculated out using the equations of motion.

That does not change the distance traveled along the principle axis however. That distance is what is used to resolve the position of the moving frame of reference.

Kettenhunde
06-14-2010, 10:23 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">the linear approximation over the entire maneuver is very inaccurate. </div></BLOCKQUOTE>

It is very accurate within the realm of relative performance.

There is no magical "other process" that is going to change the relative distance along the fixed axis.

Factoring in density effects will give you more specific numbers but will not change the relative outcome.

As in the turning performance discussion, we seem to have a few individuals who do not grasp density is an environmental effect that effects all aircraft equally. It does nothing to change relative performance.

Constant EAS climbs are the standard method used to determine climb performance.

In fact, it is a valid assumption to use EAS results as a good approximation of the speeds the pilot will read on his airspeed indicator while flying the airplane.

If the airplane out climbs another design in EAS, it will out climb it when we convert to TAS as well.

That this is such an issue with a few "knowledgeable" people is telling.

I believe FC statement about "learning aerodynamics in an hour at the library" was a very honest revelation.

JtD
06-14-2010, 11:38 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Kettenhunde:

It is very accurate within the realm of relative performance. </div></BLOCKQUOTE>

Then why are you getting wrong results?

Just for illustrative purposes, take your "zoom climb in a dog fight" situation, and change the climb angle to 30. You'll end up with the Spitfire outzooming the 190 by 2500 feet! Do you think that that is in any way resembling real world physics? In my opnion it's not, it's a result of your faulty method.

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Factoring in density effects will give you more specific numbers but will not change the relative outcome.

As in the turning performance discussion, we seem to have a few individuals who do not grasp density is an environmental effect that effects all aircraft equally. It does nothing to change relative performance. </div></BLOCKQUOTE>

Sorry, but the plane going 300 EAS at 0 alt is considerably slower than a plane going 300 EAS at 10000 alt. So it does a lot to change relative performance.

Holtzauge
06-14-2010, 12:19 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by JtD:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">
Originally posted by Kettenhunde:

That is how the physical world works. </div></BLOCKQUOTE>

14.7 s sustained turn time for the Spitfire. How reassuring! </div></BLOCKQUOTE>

Right, so when you are in a tight spot flying at TAS speed and limited to a measly IRL turn time of 17 s you can flip a switch on your speed indicator to "EAS" and instantly reduce your turntime to 14.7 s.

That's physics for ya!

Kettenhunde
06-14-2010, 03:32 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">So it does a lot to change relative performance. </div></BLOCKQUOTE>

No it does not. The specific performance is different but not the relative performance everything else being equal.

That means the Spitfire should not be ~200 feet above the Focke Wulf.

You guys keep attacking a method that is considered acceptable and is standard in determining aircraft relative performance.

In fact your whole inability to understand the difference between what is relative and what is specific is rather amusing.

What do I mean by that?

A Spitfire using EAS calculation takes 14.7s to complete a 360 at sea level in TAS. Most airplanes are not flown at sea level. They tend to run into the ground which is also generally in the vicinity of that altitude on a standard day.

A Focke Wulf using EAS calculations turns at 18.6 seconds to complete a 360 degree turn at sea level.

However lets take it to 10,000 feet...

The Spitfire then takes ~17.1 seconds to make a 360 degree turn.

At the same altitude our Focke Wulf takes ~21.6 seconds to complete a 360 degree turn.

Wow! The specific performance has changed BUT the relative performance is exactly the same. The Focke Wulf still cannot sustain a better level turn at its best rate of turn speed.

So if we want to know which airplane can out perform another, approximately how large the advantage, and approximately what speed performance will occur in Indicated Airspeed.......an EAS calculation works very well!

That is exactly what it is used for in the real world!

Amazing stuff, huh? http://forums.ubi.com/groupee_common/emoticons/icon_wink.gif

I would think it would be useful for folks to know what speed they should read on their games airspeed indicator than what the TAS specific performance is going to be?

You can even go crazy with it and use Calibrated airspeed, btw! Digest that concept slowly so we don't blow any brain cells.

How in world do you guys think the Indicated airspeed a Airbus 300 pilot needs to land or climb at in Denver Colorado for example is determined?

How can you get through school and not understand the concept of relative performance or airspeed is baffling.

Learning off the internet or by an hour in library, it is expected that you do not understand such concepts.

All the math I did shows is there is definitely a problem somewhere. It does not identify the problem.

It does not mean your games method of determining unsteady climb performance is wrong.

Using the limited experience I have in IL2 and my actual experience in the cockpit of many different airplanes, I would look to the issue of take off performance as a clue to the other performance effects.

Cobb the power on any high performance taildragger, even the Texan, you are going for a ride yet your simulation is well, not much of a simulation of a high performance taildragger when it comes to the Focke Wulf which has ~1.5 to ~3 times the power to weight ratio of most of today's GA high performance aerobatic aircraft.

If the thrust production is impeded at low velocity then it will significantly reduce the zoom performance observed in your game.

I don't know if that is the issue and I am just trying to offer helpful suggestions that make more sense besides the myopic thinking that says "two acceptable methods of determining aircraft performance are incorrect".

Just an observation....

Kettenhunde
06-14-2010, 04:22 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Right, so when you are in a tight spot flying at TAS speed and limited to a measly IRL turn time of 17 s you can flip a switch on your speed indicator to "EAS" and instantly reduce your turntime to 14.7 s.

That's physics for ya! </div></BLOCKQUOTE>

Here is a perfect example of what I am talking about!


You think this poster understands or has ever had it explained outside some internet buddies?

LMAO.....

Kettenhunde
06-14-2010, 10:02 PM
http://www.nar-associates.com/...art2_wide_screen.pdf (http://www.nar-associates.com/technical-flying/altitude/part2/altitude_part2_wide_screen.pdf)

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content"> From Naval Air Warfare Center - Weapons Division (NAWCWPNS), China Lake, CA

EAS Equivalent Airspeed (approximates Indicated Airspeed) (generic) </div></BLOCKQUOTE>

http://www.chinalakealumni.org/Glossary.htm


<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content"> Aircraft designers utilise the concept of equivalent airspeed [EAS] which assumes that the ASI is part of a 'perfect' system; i.e. there are no instrument or position errors or compressibility corrections, in which case EAS equals TAS at International Standard Atmosphere sea level conditions. </div></BLOCKQUOTE>

http://www.auf.asn.au/groundschool/CAS_EAS.html

JtD
06-14-2010, 10:41 PM
Okay, since you can't do it yourself, here are the limits of your linear approach:

190A-8 vs. Spitfire LF IX zoom climbs - your calculation:
-----
Zoom climb from 240KEAS mph to 94.4KEAS at a 45 degree angle:
240KEAS = 405.6fps
Zoom Angle 45 degrees
Vs = 94.4KEAS = 159.53 fps

Zoom height:
Sum the forces on the flight path -
9418lbs * sin 45 = 6659.5bs
2935.5 lbs 6659.5lbs = -3723lbs

a = F/m
m = 9418lbs/32.2 = 292.5lb-s^2/ft
a= 3723lb/292.5lb-s^2/ft
a = 12.7 ft/s^2

s = (V1^2 V2^2 ) / 2a
s = (405.6^2 159.53^2)/(2 * 12.7 ft/s^2) = 5475 ft
5475 ft * sin 45 = 3871 ft

Zoom climb from 149 KEAS to 80KEAS at a 45 degree angle:
149KEAS = 251.8 fps
Zoom Angle 45 degrees
Vs = 80 KEAS = 135.2fps

Zoom height:

Sum the forces on the flight path -
7450lbs * sin 45 = 5267lbs
3409.5lbs 5267lbs = 1857.5lbs

a = F/m
m = 7450lbs/32.2 = 231 lb-s^2/ft
a= 1857.5lb/231lb-s^2/ft
a = 8 ft/s^2

s = (V1^2 V2^2 ) / 2a
s = (251.8^2 135.2^2)/(2 * 8 ft/s^2) = 2820 ft
2820 ft * sin 45 = 1994 ft

Your conclusion: the FW-190 ends up 1877 feet above the Spitfire
-----

Now, I'm reducing the zoom climb angle to 30. Nothing else.

Zoom climb from 240KEAS mph to 94.4KEAS at a 30 degree angle:
240KEAS = 405.6fps
Zoom Angle 30 degrees
Vs = 94.4KEAS = 159.53 fps

Zoom height:
Sum the forces on the flight path -
9418lbs * sin 30 = 4709lbs
2935.5 lbs 4709lbs = -1774lbs

a = F/m
m = 9418lbs/32.2 = 292.5lb-s^2/ft
a= 1774lb/292.5lb-s^2/ft
a = 6.1 ft/s^2

s = (V1^2 V2^2 ) / 2a
s = (405.6^2 159.53^2)/(2 * 6.1 ft/s^2) = 11400 ft
11400 ft * sin 30 = 5700 ft

Zoom climb from 149 KEAS to 80KEAS at a 30 degree angle:
149KEAS = 251.8 fps
Zoom Angle 30 degrees
Vs = 80 KEAS = 135.2fps

Zoom height:

Sum the forces on the flight path -
7450lbs * sin 30 = 3725lbs
3409.5lbs 3725lbs = 317lbs

a = F/m
m = 7450lbs/32.2 = 231 lb-s^2/ft
a= 317lb/231lb-s^2/ft
a = 1.4 ft/s^2

s = (V1^2 V2^2 ) / 2a
s = (251.8^2 135.2^2)/(2 * 1.4 ft/s^2) = 16100 ft
16100 ft * sin 30 = 8050 ft

Conclusion: the FW-190 ends up 2350 feet below the Spitfire

This does not reflect the workings of the real world. The method is insufficient, both in terms of absolute and relative performance.

I'm not even saying that it always is, but it is in this case.

Edit: Am I just arguing with Kettenhunde or is the silent public getting anything useful out of it?

Kettenhunde
06-15-2010, 04:42 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">This does not reflect the workings of the real world. </div></BLOCKQUOTE>

Sure it does.

It reflects the Spitfire is very close to sustained performance under those conditions and not so much a zoom climb.

We can tell by that your "testing" has been silly as your results at too low an angle that skirts the Spitfire sustained performance.

The result is a hat trick that does not illustrate the correct principle of zoom climb performance.

Now try in your game to test a zoom at a higher angle so we are testing zoom and not sustained performance differences.

Kettenhunde
06-15-2010, 05:55 AM
BTW,

If you have any doubts that the majority of that climb profile is sustained performance for the Spitfire, just work out the timeline.

The Focke Wulf reaches max altitude in 61 seconds.

The Spitfire requires 152 seconds...

20 second zoom the Focke Wulf moves 1200 feet along the vector while the Spitfire moves only 280 feet.....


Who outzooms who???

Holtzauge
06-15-2010, 10:55 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Kettenhunde:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Right, so when you are in a tight spot flying at TAS speed and limited to a measly IRL turn time of 17 s you can flip a switch on your speed indicator to "EAS" and instantly reduce your turntime to 14.7 s.

That's physics for ya! </div></BLOCKQUOTE>

Here is a perfect example of what I am talking about!


You think this poster understands or has ever had it explained outside some internet buddies?

LMAO..... </div></BLOCKQUOTE>

Boy, that one certainly flew over you head.....

Tip for the dimwitted: Google "humor" and "irony"

JtD
06-15-2010, 11:57 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Kettenhunde:
It reflects the Spitfire is very close to sustained performance under those conditions and not so much a zoom climb. </div></BLOCKQUOTE>

A sustained climb of 27 m/s. Hm.

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">The Focke Wulf reaches max altitude in 61 seconds. </div></BLOCKQUOTE>

40 seconds according to your math.

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">The Spitfire requires 152 seconds... </div></BLOCKQUOTE>

83 seconds according to your math.

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">20 second zoom the Focke Wulf moves 1200 feet along the vector </div></BLOCKQUOTE>
http://forums.ubi.com/groupee_common/emoticons/icon_rolleyes.gif
...therefore with an average speed of 60 fps, which is a ridiculously low speed.

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content"> while the Spitfire moves only 280 feet..... </div></BLOCKQUOTE>
http://forums.ubi.com/groupee_common/emoticons/icon_rolleyes.gif
...therefore with an average speed of 14fps, which is an even more ridiculously low speed.

Thanks for demonstrating your abilities this way, if anyone still had doubts about the accuracy of your other statements, this will certainly have helped pointing them in the right direction.

Anyway, since no one of the silent public seems to be getting anything useful out of it and I've got better things to do then to repeatedly show the limits of a simplification to someone who refuses to even consider arguments, I'll be leaving that at that.

Have a nice day!

Holtzauge
06-15-2010, 01:37 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by JtD:
Anyway, since no one of the silent public seems to be getting anything useful out of it and I've got better things to do then to repeatedly show the limits of a simplification to someone who refuses to even consider arguments, I'll be leaving that at that.

Have a nice day! </div></BLOCKQUOTE>

Well I for one think you have done a splendid job of exposing the creationist flight mechanics preached by Reverand Kettenhunde. http://forums.ubi.com/images/smilies/25.gif

Hopefully you have won over a few souls to evolutionary flight mechanics as well!

M_Gunz
06-16-2010, 07:10 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by trashcanUK:
Thanks, I always thought that 1.94 = 1 http://forums.ubi.com/groupee_common/emoticons/icon_rolleyes.gif </div></BLOCKQUOTE>

Nerf joke! Try again. Significant digits is not about rounding.

2500 is 2 significant digits, '2500.' is 4 significant digits.
1.94 is 3 significant digits unless someone just copied everything out of the calculator when answer should have been 2.

Rounding off reduces significant digits yet sometimes you round to keep the precision of the answer in the same ballpark
as that of the input data. 1.23 x 4.56 = 5.61 is valid even when the calculator says 5.6088. The input is to 3 digits.
You can end up with extra digits but that doesn't increase the precision of the answer beyond that of the input, except of
course in the minds of those who don't know better!

The placement of the decimal point is MOOT. You know powers of 10? I don't need to write 24 digits to use Avogadro's number.

Most of Ketts stuff, I see adherence to that. He keeps it straight enough for the input precision.
Sin 45 can be 70% or 71% or .7 or .71 or .7071 depending on what you're doing with it, though he got the value wrong a while ago.

But nobody gets everything perfect all the time and then some twonk not only pounces but pounces on the wrong error!
Go ahead, joke away. If you knew that all along then why you made that post?

Kettenhunde
06-18-2010, 03:40 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content"> This does not reflect the workings of the real world. The method is insufficient, both in terms of absolute and relative performance.
</div></BLOCKQUOTE>

Actually it very much reflects the physical world and how airplanes perform.

If you went to school, you would recognize it as the axis estabilishment for Small Change Theory.

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content"> therefore with an average speed of 60 fps, which is a ridiculously low speed.
</div></BLOCKQUOTE>

Yes I used aceleration which is negative and could not edit or log back on to fix it when I realized the error.

Using the correct formulation at the conditions JtD set of a 30 degree climb angle for both aircraft, lets examine the rate of climb.

For our Focke Wulf, which must do everything faster, including climb speeds:

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content"> 40 seconds according to your math.
</div></BLOCKQUOTE>

Time = Distance / Average Velocity

Time = 11400ft / 282.5fps

Time = 40.34 s

For our Spitfire:

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content"> 83 seconds according to your math.
</div></BLOCKQUOTE>

Time = 16100 ft / 193.5fps

Time = 83.2 s

Zoom height of the Spitfire when the Focke Wulf reaches 11400 ft:

Distance = Average Velocity x Time

Distance = 193.5 * 40.35 s

Distance = 7808 ft

The Spitfire is 3592 ft or ~1.5 Km behind the Focke Wulf on the same vector when the Focke Wulf reaches hammerhead position.

It takes the Spitfire:

Time = Distance / Average Velocity

Time = 3592 ft / 193.5 fps

Time = 18.5 seconds to reach the 11400 ft

That is 18.5 seconds the Focke Wulf has to manuver or complete its hammerhad after gaining 1796 ft &lt;3592*sin 30&gt; in altitude because of the fact the Focke Wulf is traveling at a faster velocity.

I think the term in these games is "rope a dope"?

Now this climb profile JtD selected is very close to sustainable performance for the Spitfire. That is why it is traveling so slow and gaining so much altitude.

At a higher zoom angle, not only will the Focke Wulf traveling faster to altitude, it will also gain more altitude.

The relative performance will remain intact no matter what formulation you use.

If we went with Total Energy concepts for the same conditions JtD set:

Focke Wulf Energy height at sea level at a Velocity of 405.6fps:

Energy Height = 2554.5 ft
Specific Excess Power = 49.5 fps

Spitfire Eh at sea level at a velocity of 251.8 fps:

Energy Height = 984 ft

Specific Excess Power = 77.17 fps

The Spitfire Energy Height or its ability to reach a zero airspeed zoom straight up is some 1570 ft lower than the Focke Wulfs.

Lets look at the Energy height and specific excess power at 40.35 seconds into the zoom.

Focke Wulf Energy Height = 11795 ft

Focke Wulf Specific Excess Power = 80 fps

Spitfire Energy Height = 8384 ft

Spitfire Specific Excess power = 82.29 fps

So that is two acceptable means of comparing aircraft performance that agree.

Seeing this performance depends on how the aircraft is flown. It is important to control the load on the Focke Wulf in the begining of the zoom. The Focke Wulf is just above corner velocity and can generate ~6.48G's in an abrupt pull up. That's is akin to throwing an anchor out right at the begining of the zoom.

The Spitfire is well below its corner speed and can only generate ~3.4 G's.

Kettenhunde
06-18-2010, 06:03 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">He keeps it straight enough for the input precision. </div></BLOCKQUOTE>

At this level that is all you can do. There just is not enough measured data for anything else.

Anyone who tries to tell you they have specific performance and have any kind of specific accuracy beyond a performance trend is full of it.

Might as well be selling swamp land in Florida.

trashcanUK
06-18-2010, 06:41 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by M_Gunz:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by trashcanUK:
Thanks, I always thought that 1.94 = 1 http://forums.ubi.com/groupee_common/emoticons/icon_rolleyes.gif </div></BLOCKQUOTE>

Nerf joke! Try again. Significant digits is not about rounding.

2500 is 2 significant digits, '2500.' is 4 significant digits.
1.94 is 3 significant digits unless someone just copied everything out of the calculator when answer should have been 2.

Rounding off reduces significant digits yet sometimes you round to keep the precision of the answer in the same ballpark
as that of the input data. 1.23 x 4.56 = 5.61 is valid even when the calculator says 5.6088. The input is to 3 digits.
You can end up with extra digits but that doesn't increase the precision of the answer beyond that of the input, except of
course in the minds of those who don't know better!

The placement of the decimal point is MOOT. You know powers of 10? I don't need to write 24 digits to use Avogadro's number.

Most of Ketts stuff, I see adherence to that. He keeps it straight enough for the input precision.
Sin 45 can be 70% or 71% or .7 or .71 or .7071 depending on what you're doing with it, though he got the value wrong a while ago.

But nobody gets everything perfect all the time and then some twonk not only pounces but pounces on the wrong error!
Go ahead, joke away. If you knew that all along then why you made that post? </div></BLOCKQUOTE>

My apologies, I'm guessing sarcasm doesn't play well on a forum such as this http://forums.ubi.com/groupee_common/emoticons/icon_frown.gif
I was using the Kettenhunde technique of focussing on a small detail of another persons contribution, selective quotations and then belittling them on a broader scale whilst refusing to accept that any other of their opinions have any validity.
I realise now that my attempts were amateurish and not befitting of such luminaries as your good self.
Please accept my whole hearted apologies http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif

Gaston444
06-18-2010, 07:44 PM
Quote, Kettenhunde: "You guys keep attacking a method that is considered acceptable and is standard in determining aircraft relative performance."

-This is simply not the way aircrafts are designed: No aircraft designer would make a "relative" (meaning how one design performs vs another SIMILAR INTENT design) performance claim...

No engineer will ever tell you that one fighter type will out-turn, out-maneuver or out-zoom another fighter type without clear test flight data: At best he will make a cautious prediction if there are gross differences in design... And by gross I mean gross... And even gross design differences are not always enough, being completely counter-intuitive in result, as the FW-190 turn-fighting vs Spitfire issue demonstrates...

Think about it: If such things as relative performance were within the reach of such a low-cost method as simply scribling vectors and formulas on a sheet of paper, ALL fighter designs with similar specification requirements would look the same within a fraction of an inch...

To compound the obvious need for flight testing before even one airframe is ordered (Even the desperate crash programme of the He-162 faced stubborn Luftwaffe insistence on operational testing, this even beyond actual flight testing), we are here faced with POST-WAR formulas that might be vaguely useful for a very "rough" prediction on propulsion aircraft, but these calculations are so pathetically crude they do not consider traction from the front, from a flat disc that tends to increase its thrust at low speed, and in a way that counter-acts directional input, a difference compared to propulsion from the rear from a rounded-end CONE or valve-shaped purchase area, that loses thrust as it slows down...

This discussion over decimals is like people argueing over milimeters of progression, when you don't even know on which side of the planet you are...

So the pathetic "doghouse" charts (which for WWII types, are little more than perfectly intuitive mental masturbation) are still seen as authoritative for WWII types, and the issue of the 6 G "Corner Speed" being tested in 1989 at a minimum of 380-400 MPH is not even addressed...

Those 1989 professional test pilots probably just imagined that the MINIMUM speed they could pull 6 Gs was close to 380-400 MPH on a P-51D...

But if the "doghouse" chart says around 240-280 MPH, then the "doghouse" supercedes actual tests!?!

Let me put it this way: Can you, with your calculated deductions, explain to me why a medium bomber like the Ki-67 "Peggy" could perform loops or out-turn most single-engine fighter types of its day?

What specific area of its design allowed this?

Gaston

AndyJWest
06-18-2010, 07:59 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Can you, with your calculated deductions, explain to me why a medium bomber like the Ki-67 "Peggy" could perform loops or out-turn most single-engine fighter types of its day? </div></BLOCKQUOTE>
Can you provide evidence, from a verifiable primary source, that it could? Under what circumstances? Also, clarify whether you mean 'out turn' is an instantaneous turn, or as a sustained turn, and whether you are talking about rate of turn, or turn radius.

And when you've done that, can you explain why your endless crap about 'flat discs' and 'cones' has any relevance to aerodynamics, using calculations which concur with known physical laws?

WTE_Galway
06-18-2010, 08:19 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by AndyJWest:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Can you, with your calculated deductions, explain to me why a medium bomber like the Ki-67 "Peggy" could perform loops or out-turn most single-engine fighter types of its day? </div></BLOCKQUOTE>
Can you provide evidence, from a verifiable primary source, that it could? Under what circumstances? Also, clarify whether you mean 'out turn' is an instantaneous turn, or as a sustained turn, and whether you are talking about rate of turn, or turn radius.
</div></BLOCKQUOTE>

It certainly is claimed to have been capable of looping .. obviously with no bomb load.

Remember that the ki67 eventually evolved into the ki109 heavy fighter http://forums.ubi.com/groupee_common/emoticons/icon_biggrin.gif


http://upload.wikimedia.org/wikipedia/commons/d/d5/Mitsubishi_Ki-109.jpg

AndyJWest
06-18-2010, 08:48 PM
I've heard of all sorts of aircraft being looped, from a Walrus to a DC-10 (allegedly). I've never seen any real evidence that looping was considered a sensible fighter tactic though. I'm much more interested in Gaston's claims about the turn characteristics of the Ki-67 - don't give him an excuse to avoid answering...

M_Gunz
06-18-2010, 10:24 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by trashcanUK:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by M_Gunz:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by trashcanUK:
Thanks, I always thought that 1.94 = 1 http://forums.ubi.com/groupee_common/emoticons/icon_rolleyes.gif </div></BLOCKQUOTE>

Nerf joke! Try again. Significant digits is not about rounding.

2500 is 2 significant digits, '2500.' is 4 significant digits.
1.94 is 3 significant digits unless someone just copied everything out of the calculator when answer should have been 2.

Rounding off reduces significant digits yet sometimes you round to keep the precision of the answer in the same ballpark
as that of the input data. 1.23 x 4.56 = 5.61 is valid even when the calculator says 5.6088. The input is to 3 digits.
You can end up with extra digits but that doesn't increase the precision of the answer beyond that of the input, except of
course in the minds of those who don't know better!

The placement of the decimal point is MOOT. You know powers of 10? I don't need to write 24 digits to use Avogadro's number.

Most of Ketts stuff, I see adherence to that. He keeps it straight enough for the input precision.
Sin 45 can be 70% or 71% or .7 or .71 or .7071 depending on what you're doing with it, though he got the value wrong a while ago.

But nobody gets everything perfect all the time and then some twonk not only pounces but pounces on the wrong error!
Go ahead, joke away. If you knew that all along then why you made that post? </div></BLOCKQUOTE>

My apologies, I'm guessing sarcasm doesn't play well on a forum such as this http://forums.ubi.com/groupee_common/emoticons/icon_frown.gif
I was using the Kettenhunde technique of focussing on a small detail of another persons contribution, selective quotations and then belittling them on a broader scale whilst refusing to accept that any other of their opinions have any validity.
I realise now that my attempts were amateurish and not befitting of such luminaries as your good self.
Please accept my whole hearted apologies http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif </div></BLOCKQUOTE>

And I was replying to your troll in a manner roughly equal to the grace you were using. Sorry you missed that.
I really thought you could have done better than play math-tard, perhaps I was right?
You -were- just going for a cheap shot then, right?

M_Gunz
06-18-2010, 10:53 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by AndyJWest:
I've heard of all sorts of aircraft being looped, from a Walrus to a DC-10 (allegedly). I've never seen any real evidence that looping was considered a sensible fighter tactic though. I'm much more interested in Gaston's claims about the turn characteristics of the Ki-67 - don't give him an excuse to avoid answering... </div></BLOCKQUOTE>

With enough lift, power and structure to carry a heavy payload and no payload.. why shouldn't those planes be able to perform
a maneuver that some WWI fighters could do successively?

The really smack-part is in taking the reported ability to do that and implying a full bomb-load's worth of manure from it.

The RAEE did perform flight tests to build their doghouse charts from. They -tested- their work as opposed to coming up with
theories in the Aristotelian manner backed with buzzwords copped from non-applicable engineering terms. Note how "stress risers"
and "differential disk loading" apply to the Spitfire but not to the Focke-Wulf? That's because when you have the attention
span of a spoiled six year old on a Christmas morning sugar-rush nothing in one paragraph let alone post applies to the next.

What can be derived from a few simple tests does enable the aero engineers to chart the performance in between to a decent
level of accuracy. You won't find some magic bubble region where the plane performs twice as well suddenly though you may
find bumps of a few percent from predicted in places which funny enough show up on the war-time RAEE charts that were posted
here more than a few times ***because they did run a lot of flight tests and found those places shown***.

But we are to believe that the FW-190's were really great low-speed turning fighters completely on the basis of misinterpreted
quotes and snips from quotes while of course to quote the same person who does that:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">No engineer will ever tell you that one fighter type will out-turn, out-maneuver or out-zoom another fighter type without clear test flight data: </div></BLOCKQUOTE>
But it's okay since G is no engineer unless you count "engineering" BS to get seriously craved attention.

JtD
06-19-2010, 01:36 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">This is simply not the way aircrafts are designed: No aircraft designer would make a "relative" (meaning how one design performs vs another SIMILAR INTENT design) performance claim... </div></BLOCKQUOTE>

Exactly. Aircraft designers are idiots who just design a plane, and after it's finished find out what it can do. The F-22 was intended as a cargo helicopter, but when they found out it was capable of super cruising, they made it an air superiority fighter instead.
It's been this way since the Wright brothers built a bicycle that accidentally lifted off at higher speeds.

Kettenhunde
06-19-2010, 06:38 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">No engineer will ever tell you that one fighter type will out-turn, out-maneuver or out-zoom another fighter type without clear test flight data: </div></BLOCKQUOTE>


Wow, this is not correct. How in the world are you going to sell a product to a customer when you cannot tell the customer what the vehicle is going to be capable of doing? Simply put you can't unless the customer is just an idiot who can't wait to give his money away.

Engineering teams will most certainly make accurate specific performance predictions.

Amateurs without access to the same data will not be able to make specific performance predictions.

What amateurs without access to the same data though can do is make accurate predictions of the performance trends.

Kettenhunde
06-19-2010, 06:55 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Can you, with your calculated deductions, explain to me why a medium bomber like the Ki-67 "Peggy" could perform loops or out-turn most single-engine fighter types of its day? </div></BLOCKQUOTE>

Any airplane can be looped Gaston. Not all pilots can loop any airplane.

http://www.youtube.com/watch?v=pUYfKFMXJYE

tmp190
06-19-2010, 06:57 AM
Kettenhunde seems to have attitude with the "game". In reality the physics calculations in the best sims go way beyond a few lines of simplistic calculation.
Don't insult our simu.. err game http://forums.ubi.com/groupee_common/emoticons/icon_wink.gif

Kettenhunde
06-19-2010, 07:09 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Kettenhunde seems to have attitude with the "game". </div></BLOCKQUOTE>


LOL, I have stated many times what my feeling are towards IL2 and other games.

I am glad they are around as they spark interest in both aviation and historical aircraft.

That is good thing!

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content"> In reality the physics calculations in the best sims go way beyond a few lines of simplistic calculation. </div></BLOCKQUOTE>

I helped build a few FM for games in the past. We all the time have people wanting us to help with their game.

Making the calculation more complicated is not going to change the performance trends at all. Things are not suddenly going to fall up instead of down.

The calculation is intentionally kept simple so that readers can follow it and understand the principles as to why things occur in aircraft peformance. For example, the relationship of velocity to turn radius or zoom climb.

If a airplane has a useful advantage, then it will remain useful no matter what system is used.

The calculations are done in EAS so that you can transfer them to your games Indicated Airspeed without conversion.

You do have to watch your airspeed indicator when maneuvering in your game in order to insure you are at the maximum performance point, right?

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content"> Crumpp says:
So that is two acceptable means of comparing aircraft performance that agree.

Seeing this performance depends on how the aircraft is flown. It is important to control the load on the Focke Wulf in the begining of the zoom. The Focke Wulf is just above corner velocity and can generate ~6.48G's in an abrupt pull up. That's is akin to throwing an anchor out right at the begining of the zoom.

The Spitfire is well below its corner speed and can only generate ~3.4 G's.

</div></BLOCKQUOTE>

M_Gunz
06-19-2010, 10:02 AM
IMO with different planes engines comparing very differently at different altitudes there are historic matches
that compared differently as to turning at different altitudes. 109E vs Hurricane in the BoB reversed as to
turning circles between much above and much below 8000 ft. Russian single-stage boosted fighters vs most German
fighters much above or below certain altitudes also had reversed performance trends.
This IL2 FW 190A-8 vs Spit IX, both at limited boost (IL2 100%) are not so far apart at seal level and the top
speeds do reverse not too far up.

This is why I don't like to use EAS alone to say relative performance at all altitudes. It does not cover differences
in power with altitude and the results of that. It does not tell me excess power which I believe is an important
factor in all but instantaneous performance at speed.

Kettenhunde
06-19-2010, 10:18 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">his is why I don't like to use EAS alone to say relative performance at all altitudes. It does not cover differences in power with altitude </div></BLOCKQUOTE>

It is extremely easy to adjust the power to any altitude, M_Gunz.

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content"> It does not tell me excess power </div></BLOCKQUOTE>

You are mistaken on this. It most certainly does tell you excess power.

M_Gunz
06-19-2010, 12:24 PM
I can tell SEP just from EAS and data at one altitude? No.
Relative performance is the same at all altitudes? No.

EAS or TAS, there's gotta be adjustments. I won't say which is easier because I can't but I know enough to know
there's gotta be adjustments for power at altitude. And I think that hasn't been addressed completely by everyone
in these discussions and it lies near the base of so many mis-arguments (20 pages, easy) it's not funny.

Kettenhunde
06-19-2010, 06:46 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">I can tell SEP just from EAS and data at one altitude? No. </div></BLOCKQUOTE>


You get a very good ballpark M_Gunz.

You are talking about a ~100lb change in relative forces.

Things are not suddenly going to fall up....


<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content"> Relative performance is the same at all altitudes? No. </div></BLOCKQUOTE>

Of course not, but is much easier to adjust to find out the performance for EAS than TAS. Relative performance is not the same for all altitudes no matter what system you use. EAS not only returns a good approximation of the Indicated Airspeed, it works over large blocks of altitude until FTH is reached.

You only have to change the power.

You are correct in that in a TAS calculation, you also have to adjust the power for altitude AND you have account for the density changes.

Kettenhunde
06-19-2010, 06:53 PM
Why do you think you cannot change power with altitude when using EAS, M_Gunz?

M_Gunz
06-19-2010, 08:35 PM
Oh you can change them. It's just that the relation at one altitude is not always the relation at another.
As example, 4000 ft and under the BoB Hurricane would out-turn the BoB 109 in continuous turns but 12000 ft
and up the 109 turned continuously better and had a strong edge in the short term as well. At around 8000 ft
they were almost on par.
The Hurricane airframe had the better instantaneous turn for any EAS but when the engine was gasping that
did it little good beyond the first couple of angles after a dive onto target. Being in the right place and
height to make the bounce was one of Britain's trump cards that was played often, most British BoB victories
were made in Hurricanes but it didn't have the stamina at bomber altitudes for a sustained fight with a 109.

So I can't take an account of Hurricane vs 109 at 15000 ft and apply it to the same match at 3000 ft and IMO
some people see EAS relations and think they are supposed to be held regardless of altitude for some reasons,
which is not true. There seem to be a few key assumptions about use of EAS which don't fit behind a number of
'what you meant' style arguments here.
As far as I can tell, relative performance does not match at all altitudes except for relative instantaneous
or very short term performance given certain speeds without saying how they were arrived at and even then care
needs to be taken to avoid getting things wrong or making statements that will mislead some or most readers.

Of course in flight sim forums people seem to get mislead even without EAS being mentioned.

WTE_Galway
06-19-2010, 09:07 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by M_Gunz:
As far as I can tell, relative performance does not match at all altitudes except for relative instantaneous
or very short term performance given certain speeds without saying how they were arrived at and even then care
needs to be taken to avoid getting things wrong or making statements that will mislead some or most readers.

Of course in flight sim forums people seem to get mislead even without EAS being mentioned. </div></BLOCKQUOTE>

The "relative" bit usually gets ignored whether over different attitudes or between different airframes. The classic example is some peoples fascination with "best" corner speed when what really matters (if you absolutely must play fair ground carousel with your opponent) is the speed that gives you the greatest advantage or sometimes least-disadvantage versus your opponent. Depending on the match-up that may be the "worst" corner speed of the opposition rather than the "best" corner speed for your own bird though its more likely some point in between the two.

M_Gunz
06-19-2010, 09:32 PM
Hey, I can't count how many times I've been in the 'lesser' plane and either nosed down or up and cut right across
the arc of the others' path and shot him down. IMO the answer is to match his tactics with others of your own even
if he flies to the strengths of your plane. If all I do is follow then I am reacting, not initiating.

Wurkeri
06-19-2010, 10:01 PM
Gunz,
I suggest some testing instead buying nonsense. You can start duplicating my test at sealevel and then repeat the same test at 2000m (then try 7000m if you want some fun ). The given autopilot settings work ok up to about 70deg zoom angle, however, at high angles the planes are pretty much uncontrollable in the end of the zoom.

The basic question is always the same; do you want to know or do you want to believe.

AndyJWest
06-19-2010, 10:16 PM
This whole debate is based on an unrealistic premise. Regardless of the particular capabilities of the aircraft involved, external considerations are significant - and may matter more than the fine details of performance. Where is the dogfight occurring? Fighting over your own territory gives added security, and allows risks to be taken. What is the fuel state of the aircraft involved? How much ammunition do they have remaining? I'd suspect that in most real dogfights, factors like this were more significant than minor differences in performance (especially since neither combatant would know the capabilities of the other with any degree of confidence). Relying on mathematical 'certainties', rather than treating everything as a fluid and uncertain stream of events sounds like a sure-fire way to get shot down.

M_Gunz
06-20-2010, 04:17 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Wurkeri:
Gunz,
I suggest some testing instead buying nonsense. You can start duplicating my test at sealevel and then repeat the same test at 2000m (then try 7000m if you want some fun ). The given autopilot settings work ok up to about 70deg zoom angle, however, at high angles the planes are pretty much uncontrollable in the end of the zoom.

The basic question is always the same; do you want to know or do you want to believe. </div></BLOCKQUOTE>

Looking at your graphs and JtD's I see that using limited zooms ending at higher speeds benefit the faster plane.
If you're anywhere close at the start you can end up over the other with enough speed to do something about it
even if the sucker does decide to eventually rise higher while slowing down to easy target speed. And for added
bonus, I've been through that in IL2 before and my gunnery and AC stability (thanks to my speed) has been good
enough to cash the difference in for me. Prop-hangers flying at 240kph and less are not hard targets at long range.

I get choices in the nonsense for sale here. Which item do you mean? The FW vs Spit as laid out in the zoom tests
has a small total percent of speed margin at the start which in the long term at a low zoom angle is reversed.
580/540 is about 7.4%. However in the short term a 40 kph advantage is useful. The big blip though is restriction
from using WEP which for the IL2 FW 190A-8 is a bigger handicap than for the Spit IX's.

What one plane can achieve 33+% later than another has no place in my bag of combat tactics. My speed IAS does,
and my IAS relative to my enemy's speed IAS do have a big place in my situational evaluation and tactical choices.
Don't you worry, I don't let anything I can't put to use make to my "tactical shopping cart".

Be it an FW, a P-47, a P-51 or any other fast plane with a good to stellar roll rate, a steep zoom and roll is my
#1 choice of way to change direction and I never ever want to get caught wallowing along where my roll is slow and
I can't pull over 2G's regardless of who has the height advantage. I'd rather have speed than equivalent height.
As long as I have that I can fly my plane to its strengths and choose my tactics. Zoom to stall has no place for me.

M_Gunz
06-20-2010, 04:19 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Wurkeri:
Gunz,
I suggest some testing instead buying nonsense. </div></BLOCKQUOTE>

BTW, what nonsense do you see me buying? Perhaps one or -both- of us is misunderstanding the other?
That is easy to do! Easier than not! Please quote me if that would help.

Kettenhunde
06-20-2010, 05:42 AM
A suggestion would be to calculate several zoom climb profiles and then test them in your game.

What you should see is in shallow climb near sustained performance is the only area that the Spitfire can produce more height in a zoom.

Those conditions are a hat trick and do not illustrate the correct general principle of velocity.

Even under those conditions of a very shallow climb, the Focke Wulf will reach its zoom altitude before the Spitfire due to its faster velocity.

When you increase the zoom angle, the Focke Wulf will end up higher.

That is the trends you should see and how the physical world works.

Kettenhunde
06-20-2010, 06:20 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">some people see EAS relations and think they are supposed to be held regardless of altitude for some reasons, </div></BLOCKQUOTE>


Why would somebody think that? The only reason to think that is the fact they have never seen it before. It looks like snakeoil because they do not understand it. It is different from what they were taught to parrot from some Radio Control Model Club.

No one has ever said that and in fact you have asked multiple times about EAS and altitude.

There are multiple methods of converting EAS to TAS performance as well. I think I have posted at least two of them on these boards.

Facts are it is the most common speed you will use in formal classes because of the convenience of it.

I don't see how it is possible for anyone can get through a class and not understand it.

M_Gunz
06-20-2010, 06:56 AM
I'm going off the arguments about EAS.

Kettenhunde
06-20-2010, 07:36 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">I'm going off the arguments about EAS. </div></BLOCKQUOTE>

Whose arguments? Where is this nonsense coming from?

tmp190
06-20-2010, 01:36 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Kettenhunde:
I helped build a few FM for games in the past. We all the time have people wanting us to help with their game.
</div></BLOCKQUOTE>

Can you tell which games ?

M_Gunz
06-20-2010, 02:26 PM
Nonsense indeed. Every time the subject comes up here over the last few years it turns into feeding time
at the Zoo.

It's not just EAS being used in a discussion that does it. Bring up 50 cal effectiveness or any other
subject where beliefs and understandings vary almost completely here. We've even had one fine thread
about UFO's and aliens here on Earth.

The thing is that EAS is not necessary to use in these discussions, is it? Given the responses, why do it?

Kettenhunde
06-20-2010, 04:59 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">The thing is that EAS is not necessary to use in these discussions, is it? Given the responses, why do it? </div></BLOCKQUOTE>

I can't help ignorance that insists on being ignorant, M_Gunz.

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content"> To eliminate altitude effects aircraft performance calculations are often done at equivalent air speed EAS (see below). Published data may be quoted at other airspeed definitions. It may be necessary to convert between the various speeds so it is important to understand airspeed definitions. </div></BLOCKQUOTE>

http://www.elsevierdirect.com/...s/data-d/default.htm (http://www.elsevierdirect.com/companions/9780340741528/appendices/data-d/default.htm)

Right below equation 3.9:

http://books.google.com/books?...t%20airspeed&f=false (http://books.google.com/books?id=a_c2V0zAFwcC&lpg=PA79&ots=ZD9_5Quwti&dq=aircraft%20performance%20equivalent%20airspeed&pg=PA83#v=onepage&q=aircraft%20performance%20equivalent%20airspeed&f=false)

I use EAS because for your game it is more useful to speak in terms of EAS than TAS. EAS is a very good approximation of IAS. It will translate directly to what your game shows on the airspeed indicator.

It also means I can change my spreadsheet quickly and easily as I don't have to nest a atmospheric table in it. If I need specific performance, there are multiple ways to quickly get it from EAS as well. If you read Rogers report, it says EXACTLY how I told you to convert it for TAS performance.

V-speeds are not given in TAS for propeller aircraft. TAS has only one use to a pilot, deriving ground speed for flight planning.

Kettenhunde
06-20-2010, 05:33 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Can you tell which games ? </div></BLOCKQUOTE>

http://forum.totalsims.com/vie...ostorder=asc&start=0 (http://forum.totalsims.com/viewtopic.php?t=5442&postdays=0&postorder=asc&start=0)

http://forum.totalsims.com/vie...spitfire+m03&start=0 (http://forum.totalsims.com/viewtopic.php?t=9722&postdays=0&postorder=asc&highlight=spitfire+m03&start=0)

http://forum.totalsims.com/vie...ghlight=spitfire+m03 (http://forum.totalsims.com/viewtopic.php?t=9491&highlight=spitfire+m03)

http://forum.totalsims.com/vie...ic.php?p=75783#75783 (http://forum.totalsims.com/viewtopic.php?p=75783#75783)

M_Gunz
06-21-2010, 02:06 AM
I know not to try holding certain bank of turn below some same IAS depending on the plane I fly. Or any other manuever,
all I keep IAS in mind and watch my speed always IAS.

But I also know that increased altitude my ability to reach and hold IAS drops and radius to turn opens up, even below
or at FTH.

Top speed at altitude charts would have the same relative positions with speed given as EAS rather than TAS but the
shapes would be very different than the zig-zags we see on TAS-scaled charts. Change in ability to maneuver at higher
altitudes should become more clear on an EAS-scaled chart.

If one person discusses relative performance staying the same but does not mention a host of conditions then others who
miss those implications will not be discussing the same thing due to mis-communication regardless of base causes.
In order to discuss/communicate effectively it is necessary for all parties to take responsibility for clarity and avoid
such gaps which work both ways.

Imagine two fencers dancing about a room poking different walls and bits of furniture saying 'touche' while only by
coincidence facing each other. Both look like fools, neither acting responsibly. With battles of words this not only
-can- happen, it seems to happen more often than not!
People who read loose anecdotes, aka stories, and mentally fill in missing details do a version of this that comes to
nothing less ridiculous how many times? LOADS of times! It's even worse with those who treat science as semantics to
try and manipulate how the reality works by manipulating only the words and their meanings, or to throw in terms with
similar words to semantically create concepts they then apply/misuse such as "stress risers" and "energy retention".
The terms have meanings but the terms get taken outside and beyond the meanings through ignorant semantics-magic.

JUST SO AS THAT, noticing a disconnect in a conversation and continuing along as if there is none is no better.
The difference between one side and the other proves nothing so much as bad communication although here it is
paraded on both sides as an obvious lack of credibility on the part of the other. If neither side is able to
recognize when the other is on a different topic as it were then perhaps the credibility of BOTH becomes suspect?
It's either that or the willingness to discuss the subject in a meaningful way has been lost by one or both sides.

But of course that doesn't happen here _always_. Just all too often.

Kettenhunde
06-21-2010, 09:43 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">I know not to try holding certain bank of turn below some same IAS depending on the plane I fly. Or any other manuever, all I keep IAS in mind and watch my speed always IAS. </div></BLOCKQUOTE>

Good, that is how real pilots fly and allows the calculations to be translated into performance.

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content"> Top speed at altitude charts would have the same relative positions with speed given as EAS rather than TAS </div></BLOCKQUOTE>

Yes, the relative performance is exactly the same.

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Change in ability to maneuver at higher
altitudes should become more clear on an EAS-scaled chart. </div></BLOCKQUOTE>

Correct and you have the approximate IAS you should see on your games airspeed indicator so that you can achieve the performance.

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">If one person discusses relative performance staying the same but does not mention a host of conditions then others who
miss those implications will not be discussing the same thing due to mis-communication regardless of base causes. </div></BLOCKQUOTE>

Correct. That stems from a lack of understanding what relative performance consist's of M_Gunz.

In school, it is a termed used almost daily. It is ignorant to point to any calculation at this level and claim an airplane can achieve a specific number for performance.

All you can say is that at some point, this trend will occur in the vicinity of this speed.

The relative performance is the trend.

There are so many little details that we just don't know, it is impossible to get specific performance.

How many times have you heard some folks complain about the fact I use .85 as a general propeller efficiency? Well, I use that efficiency because your typical propeller designer during WWII could easily achieve that and the way CSP work, efficiency is maximized throughout the system by design. That is one way besides vibrational harmonics propellers, engines, and aircraft are matched!

I will find some propeller plots to illustrate and post them.

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">In order to discuss/communicate effectively it is necessary for all parties to take responsibility for clarity and avoid
such gaps which work both ways. </div></BLOCKQUOTE>

Yes! However the goal has to be communication and a discussion. On Ubizoo, that seems to not be the case very often. Rather there is host of ego's who are more concerned with feeding that ego instead of learning the truth.

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content"> they then apply/misuse such as "stress risers" and "energy retention". </div></BLOCKQUOTE>

Yep....

I would love to an airplane that retained energy, LOL.

tmp190
06-21-2010, 10:36 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Kettenhunde:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Can you tell which games ? </div></BLOCKQUOTE>

http://forum.totalsims.com/vie...ostorder=asc&start=0 (http://forum.totalsims.com/viewtopic.php?t=5442&postdays=0&postorder=asc&start=0)

http://forum.totalsims.com/vie...spitfire+m03&start=0 (http://forum.totalsims.com/viewtopic.php?t=9722&postdays=0&postorder=asc&highlight=spitfire+m03&start=0)

http://forum.totalsims.com/vie...ghlight=spitfire+m03 (http://forum.totalsims.com/viewtopic.php?t=9491&highlight=spitfire+m03)

http://forum.totalsims.com/vie...ic.php?p=75783#75783 (http://forum.totalsims.com/viewtopic.php?p=75783#75783) </div></BLOCKQUOTE>

Ok thanks , many links, some of those seem not to be relevant.
But I take that the answer is Warbirds.
So, did you write the FM code for Warbirds ?

Kettenhunde
06-21-2010, 02:38 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">So, did you write the FM code for Warbirds </div></BLOCKQUOTE>


No I am not a computer programmer nor did I do it alone. I worked with their programmer, Target, who wrote the code and some dedicated players in a team effort. I deciphered the mathematical theory in the code, updated it to better account for power effects as well as stability and control to help improve the aircraft behaviors. I also interpreted and provided data on the aircraft as well and weapons.

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content"> some of those seem not to be relevant. </div></BLOCKQUOTE>

You mean the ones where they are the best FM's in the game four years after their introduction or the one pilots, as in guys who fly real airplanes including a couple of retired fighter pilots, reviewed them as being the most realistic aircraft behaviors in the game? Being an experienced pilot, aircraft owner, and degree'd in Aero-sciences, it was not like it was unfamiliar territory for me.

BTW, If you read the comments BOTH Spitfire fans AND 109 fans were pleased. They are still going strong with both fans in the game today.

Of course I am just an idiot and do not know a thing about airplanes but only when I am not screwing up the theory!

http://forums.ubi.com/images/smilies/partyhat.gif

julian265
06-21-2010, 05:31 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Kettenhunde:
Yes! However the goal has to be communication and a discussion. On Ubizoo, that seems to not be the case very often. Rather there is host of ego's who are more concerned with feeding that ego instead of learning the truth. </div></BLOCKQUOTE>

http://forums.ubi.com/images/smilies/88.gif The truth. Classic.

There's only one abnormally sized ego that I notice here, and it looks like I'm not alone with that.

Gunz, your fencing comment was an amusingly accurate analogy. I'd add one thing - again it's only one person who I notice reliably stabbing at points that were never made. There are typical text-only misunderstandings, and then there's Crumpp.

M_Gunz
06-21-2010, 07:03 PM
it's only one person who I notice reliably stabbing at points that were never made

Then you should read more posts here. Or remember them. Or stop filtering what you do read. Or stop playing politics.

arjisme
06-21-2010, 07:05 PM
^^^ agreed.

Gaston444
06-21-2010, 07:06 PM
Quote, M_Gunz: "The RAEE did perform flight tests to build their doghouse charts from. They -tested- their work as opposed to coming up with
theories in the Aristotelian manner backed with buzzwords copped from non-applicable engineering terms."


-If they did for the whole range of data points, instead of extrapolating the whole thing from a few data points, and engine output variations with speed, according to their own mathematical prejudices, can you explain to me why these charts were not repeated later in the war for the Spitfire Mark IX or Me-109G?

If these other WARTIME "doghouse" charts exist, I would REALLY be curious to see them...

Could it be the answer is that these charts weren't found to be relevant to the then increasing real-life combat experience?

Better yet, how come no other WWII flight tests came up with these magnificently useful "doghouse" charts?

Isn't the fact that only two such WWII-era "doghouse" charts exist, AFAIK, and only for two very early war variants, a clue as to their value to inform pilots in real-life combat, when it was found out the hard way what real-life combat was actually like?

And beyond all this, how do you explain that the 1989 tests by the "Society of Experimental Pilots" found the P-51D's 6G "Corner Speed" to be in the undoghouse-like minimum range of 380-400 MPH, similar with 3 other WWII fighter types? No comments on that?

As for Kettenhunde's assertion: "Any aircraft can be looped", first of all that is not true: The TBF/TBM "Avenger" comes to mind as a single-engine aircraft with all sorts of very severe flight manual restrictions on its flight envelope, as had many others...

Second, when have you heard that quote for the Ki-67, seen in many of William Green's books: "Empty, the Ki-67 could turn like a single-engined fighter and was looped regularly", applied to the very similar B-26, B-25 or even the A-20?

The closest I heard to this was the Tupolev Tu-2, which could also loop and out-turn some of the Russian single-engine fighters... (In those days "out-turn" is always sustained turning: When it is maximum-rate unsustained turns, it is easy to spot: They speak then of "radius", and this is far rarer to hear about because "radius" over a 180 turn is pretty meaningless when most turnfights in those days lasted from 900 to 9000... Remember, they kept USEFUL information in large amounts, hence hmmm... The rarity of WWII "doghouse" charts perhaps?!?)

So show us how the wing area and power-loading of a TU-2 makes it better-turning and looping than an A-20 or Pe-2... Can't wait to see the math "explain" that... But then of course the A-20 or Pe-2 were looped and out-turned fighters regularly I'm sure...

Gaston

M_Gunz
06-21-2010, 07:37 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Gaston444:
Quote, M_Gunz: "The RAEE did perform flight tests to build their doghouse charts from. They -tested- their work as opposed to coming up with
theories in the Aristotelian manner backed with buzzwords copped from non-applicable engineering terms."


-If they did for the whole range of data points, instead of extrapolating the whole thing from a few data points, and engine output variations with speed, according to their own mathematical prejudices, can you explain to me why these charts were not repeated later in the war for the Spitfire Mark IX or Me-109G? </div></BLOCKQUOTE>

Show your proof please. I don't give a ding-**** what you want to make of your own pre-suppositions.
Shize, lack of evidence is not evidence of lack.

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content"> Isn't the fact that only two such WWII-era "doghouse" charts exist, AFAIK, and only for two very early war variants, a clue as to their value to inform pilots in real-life combat, when it was found out the hard way what real-life combat was actually like? </div></BLOCKQUOTE>

Want to contend that those charts were the first and last of their kind during WWII?
Want to contend that those charts were useless in WWII when post-WWII they had still been made and used?
Want to contend that doghouse charts have never been considered useful?

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content"> And beyond all this, how do you explain that the 1989 tests by the "Society of Experimental Pilots" found the P-51D's 6G "Corner Speed" to be in the undoghouse-like minimum range of 380-400 MPH, similar with 3 other WWII fighter types? No comments on that? </div></BLOCKQUOTE>

As usual, you depend on isolated quotes mixed with your own brand of interpretation. Yet I have quoted you stating
that flight test data is required to know these things, but only in reference to someone else's quote.

HEY JULIAN! WHAT ABOUT THIS TROLL? YOU WANT TO +1 YOUR OFFICIAL COUNT?

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content"> As for Kettenhunde's assertion: "Any aircraft can be looped", first of all that is not true: The TBF/TBM "Avenger" comes to mind as a single-engine aircraft with all sorts of very severe flight manual restrictions on its flight envelope, as had many others... </div></BLOCKQUOTE>

Placards and restrictions are not physical limits.

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content"> Second, when have you heard that quote for the Ki-67, seen in many of William Green's books: "Empty, the Ki-67 could turn like a single-engined fighter and was looped regularly", </div></BLOCKQUOTE>

snip.

William Green must be stuck on it. many? HOW MANY of his books have that quote and to what end?

Do you have Alzheimer's that you can't recall the number of times your so-called points have been discredited?
Your BS ideas been shot down more times here than any German Ace had been IRL. Are you trying for more than
all of them in total? Or perhaps the whole LW? You keep flying the same old $#!+ past again and again as if
you had it right the first time. Even a 10 year old would be embarrassed yet you continue on blithely.

Kettenhunde
06-21-2010, 07:38 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">As for Kettenhunde's assertion: "Any aircraft can be looped", first of all that is not true: The TBF/TBM "Avenger" comes to mind as a single-engine aircraft with all sorts of very severe flight manual restrictions on its flight envelope, as had many others... </div></BLOCKQUOTE>


I guess the significance of the Aero-commander was completely lost on you?

An Aero-Commander cannot be looped either.....

Look at the skill Bob Hoover exhibits. He can loop this aircraft BECAUSE he is a good enough pilot to control the load factor.

http://www.youtube.com/watch?v=tOZEgKXJMCE

M_Gunz
06-21-2010, 07:51 PM
What an excellent clip!

Kettenhunde
06-21-2010, 08:02 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">how do you explain that the 1989 tests by the "Society of Experimental Pilots" found the P-51D's 6G "Corner Speed" </div></BLOCKQUOTE>



Gaston,

"corner speed" is based on the airframe limits. Warbirds are generally categorized as "Experimental Exhibition Class" with an aerobatic rating.

An aerobatic rating means 6G's is the limit.

You find "Corner speed" or Va by:

Va = 1G level stall speed * Square Root &lt;Airframe limit&gt;

In this case, airframe limit = 6G's....

Generally restored Warbirds are much lighter than the original as they do not have the Military load installed. If you lower the weight on an aircraft, you lower the stall speed. If you lower the 1G level stall speed, you will lower Va or "corner speed". The lighter the airplane, the quicker it can load the airframe.

Kettenhunde
06-21-2010, 08:05 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">What an excellent clip! </div></BLOCKQUOTE>


Bob Hoover is an amazing pilot.

My 1G rolls are rarely at 1G....