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Spartan_GR
03-18-2005, 11:55 AM
I often wonder if airplanes of ww2 that could reach speeds close to 1000km/h ( me163 etc ), would be able to reach supersonic speed if they had more powerfull engines. Would that be possible?

MEGILE
03-18-2005, 12:00 PM
Its not a question of, did they have the engine power to achieve mach 1 speeds at altitude. Certainly in a dive, planes would be able to reach the speed.. however I don't believe any WW2 era planes could take the stress of mach 1. The shockwaves would tear the plane apart..
It takes a very advanced design to allow a plane to fly super-sonic, and I don't believe the Me-163 or other jets at the time could do it.

NorrisMcWhirter
03-18-2005, 12:05 PM
^ That's what I understood of it, too. I've seen the stories of Spits that undertook high speed dives and had to be written off afterwards due to the stresses involved.

Cheers,
Norris

Spartan_GR
03-18-2005, 12:05 PM
im do not know much about airplane design ( so excuse me if my question seemed a bit stupid http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif ). Those shockwaves are the reason that when you reach high speeds the airpane starts shaking?

darkhorizon11
03-18-2005, 12:08 PM
Generally No, at least not without crashing or breaking up.

A German pilot once claimed he did in an Me 262 while diving, but its pretty much generally believed that this is untrue.

If you look at modern fighter jets their wings are very thin and smooth. Most WW2 fighters have thicker wings which gives more controllability at low speeds but at high speeds it causes compressabliity of the air in front of the wing. In laymens terms once the aircraft approaches high speed the controls freeze up and the plane becomes unflyable.

Also, the airframes at the time were not as strong as today. As an airframe breaks the barrier it goes under heavy stress and sometimes buffeting. WW2 airframes were not designed to deal with this sort of stress and many unhappy pilots would lose their wings or empenagge when approaching these speeds.

Now is it possible to get per say a Spit fire over the speed of sound if you gave it a laminar wing gave it a rocket booster on the back, or made some other extreme modifications? Possibly, but continous operations above 1.0 generally didn't come till the late 40s early 50s.

Even Yeager only broke the barrier for a few seconds and that was after many tries by a few pilots in the same aircraft.

MEGILE
03-18-2005, 12:08 PM
No, in game the shaking is down to flying at excessive airspeeds, and not down to compression or nearing mach1.

Which leads to a good point... I don't think the effects of approaching mach 1 are in-game, but I'm not 100% sure.
Gonna take a Jug upto 40,000FT and see what happens http://forums.ubi.com/groupee_common/emoticons/icon_biggrin.gif

Zyzbot
03-18-2005, 12:56 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by Spartan_GR:
I often wonder if airplanes of ww2 that could reach speeds close to 1000km/h ( me163 etc ), would be able to reach supersonic speed if they had more powerfull engines. Would that be possible? <HR></BLOCKQUOTE>

The Me-163 was not capable of supersonic speed. Info from the chief test pilot of the Me-163:

"When flying above the critical Mach number but below the speed of sound, the airplane is in the €œtransonic€ flight regime. The airspeed is less than Mach 1, but there are local bubbles of supersonic flow embedded in the overall airflow. The critical Mach number depends on the configuration of the airplane. The thicker the wing, the more the air accelerates when passing over it. Some of the early WW II fighters, notably the P-38 Lightning, began to run into some transonic aerodynamic effects at Mach numbers as low as 0.68 or 68 percent of the speed of sound. The Me-163 Komet had a critical Mach number of about 0.84.


When supersonic flow begins to appear on a wing or tail surface, the aerodynamic center moves aft, causing a nose-down pitching moment. As the Mach number increases, a shock wave forms at the aft boundary of the supersonic-flow bubble. When the shock gets strong enough it will cause the airflow to separate aft of the shock, leading to a loss of lift. This condition is called €œshock stall.€

On the Me 163, the combination of the aft shift in aerodynamic center and shock stall led to a dangerous condition known as €œMach tuck.€ If the Mach number exceeded approximately 0.85, the airplane would begin to nose down on its own. The pilot would naturally react by pulling on the stick and deflecting the elevons upward. This would cause a shock wave to form on the underside of the wing at the elevon hinge line. The elevons would shock stall and be unable to bring the nose up, causing the airplane to pitch over into an ever-steepening dive. The only hope for recovery was to wait until the airplane had dived to a lower altitude where the speed of sound is higher, thus reducing Mach number, and the elevons would regain effectiveness."

darkhorizon11
03-18-2005, 06:00 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by Megile:
No, in game the shaking is down to flying at excessive airspeeds, and not down to compression or nearing mach1.

Which leads to a good point... I don't think the effects of approaching mach 1 are in-game, but I'm not 100% sure.
Gonna take a Jug upto 40,000FT and see what happens http://forums.ubi.com/groupee_common/emoticons/icon_biggrin.gif <HR></BLOCKQUOTE>

I'm not talking about in-game at all I'm talking about RL. Who cares about in game? Structural limits are not realistically modeled in IL2 anyway, so the game isn't really a place to test this and say it holds water in RL.

MEGILE
03-18-2005, 06:18 PM
http://forums.ubi.com/images/smilies/16x16_smiley-very-happy.gif
Where did that come from DarkHorizon?
I was answering the question

<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Those shockwaves are the reason that when you reach high speeds the airpane starts shaking? <HR></BLOCKQUOTE>

The in game answer is

<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>No, in game the shaking is down to flying at excessive airspeeds, and not down to compression or nearing mach1. <HR></BLOCKQUOTE>

Who cares about how compression is modelled in game? well pretty much about everyone who wants transsonic flight modelled correctly. http://forums.ubi.com/groupee_common/emoticons/icon_biggrin.gif

Korbelz
03-18-2005, 07:27 PM
yes