PDA

View Full Version : Prop speed Fysics question

general_kalle
02-28-2008, 01:13 PM
how does it workout?

when the propeller is spinning the tip spins quicker than the center of blade, yet its run by the same engine and its one thing?

same thing with a Vinyl record.

pogobbler
02-28-2008, 01:39 PM
The prop tips and the prop roots only travel at different speeds if you consider their linear velocities, which aren't really the most relevant when dealing with rotating bodies. The more relevant measurement is the rotational velocity, the RPMs, basically, and all parts of the prop are traveling at the same rotational velocity. Yes, the prop tip's linear speed is important from a standpoint of the strength of the material it's made from and such, but it's not violating any laws by all parts not traveling at the same linear velocity.

general_kalle
02-28-2008, 01:51 PM
i think i got your point. but that was alot of difficult words http://forums.ubi.com/images/smilies/53.gif

M_Gunz
02-28-2008, 01:53 PM
Originally posted by general_kalle:
when the propeller is spinning the tip spins quicker than the center of blade, yet its run by the same engine and its one thing?

Interesting form of bait. You are indeed fishing in a very Raaaid-like dust puddle.

Urufu_Shinjiro
02-28-2008, 02:02 PM
The "fysics" was a nice touch, I loled. http://forums.ubi.com/groupee_common/emoticons/icon_wink.gif

Taylortony
02-28-2008, 05:17 PM
Think of it as the root only has to go round a small circle but the tip has to travel round a bigger circle, so in effect the tip has to move further than the root of the blade to keep up......... this is why you need the twist in the blade, because if you did not have it the tip would produce more lift as its moving faster due to having to cover a greater distance and the blade would bend and snap, so you put a twist in the blade to reduce the amount of lift generated towards the tip so you have an even lift over the length of the blade http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif

Does that help.............

Ok now to totally screw with your mind ,) a helicopter travelling fwd at a 100 KPH will have the fwd blade travelling at 100KPH plus rotor speed say 50KPH for arguments sake making a total of 150KPH, but the retreating blade will be travelling aft against the fwd speed so will be moving at 50KPH so it will roll over...http://forums.ubi.com/groupee_common/emoticons/icon_wink.gif as the lift is all on one side http://forums.ubi.com/images/smilies/winky.gif

AKA_TAGERT
02-28-2008, 10:36 PM
Originally posted by general_kalle:
how does it workout?
It's all relative http://forums.ubi.com/images/smilies/16x16_smiley-wink.gif

K_Freddie
02-29-2008, 01:11 AM
- English lesson in 'physics'.. always helps.
- Angular velocity is the same for both points.
- Linear velocity is different, as pointed out, due to the sector length difference of the angular distance travelled.
- Radius effects Sector length effects Linear velocity.

http://forums.ubi.com/groupee_common/emoticons/icon_biggrin.gif

Patriot_Act
02-29-2008, 01:31 AM
Letz uss takl a littel about da fysics of da prop.
We can tink of da prop as a disk.
The hole ting spinnz at da same rate.
RMPS are da same.
Butt, da relitave speed itz faster at da tips.
Dat'z oll.

Spellink aint my stronk point eether.

I also speak Jive and Eubonics. http://forums.ubi.com/groupee_common/emoticons/icon_razz.gif

LMAO!

P.A.

tjaika1910
03-01-2008, 09:39 AM
Dont pick on misspelled words in a foreign language. I dont care anyway and dont bother to find the ' on the keyboard either. Remember, a lot of nationalities are on this board, I wouldnt be surpriced if a majority do not have english as first language.

And besides:

Aoccdrnig to a rscheearch at Cmabrigde Uinervtisy, it deosn't mttaer in waht oredr the ltteers in a wrod are, the olny iprmoetnt tihng is taht the frist and lsat ltteer be at the rghit pclae. The rset can be a total mses and you can sitll raed it wouthit a porbelm. Tihs is bcuseae the huamn mnid deos not raed ervey lteter by istlef, but the wrod as a wlohe. Amzanig huh?

Patriot_Act
03-02-2008, 01:51 AM
Originally posted by tjaika1910:
Dont pick on misspelled words in a foreign language. I dont care anyway and dont bother to find the ' on the keyboard either. Remember, a lot of nationalities are on this board, I wouldnt be surpriced if a majority do not have english as first language.

And besides:

Aoccdrnig to a rscheearch at Cmabrigde Uinervtisy, it deosn't mttaer in waht oredr the ltteers in a wrod are, the olny iprmoetnt tihng is taht the frist and lsat ltteer be at the rghit pclae. The rset can be a total mses and you can sitll raed it wouthit a porbelm. Tihs is bcuseae the huamn mnid deos not raed ervey lteter by istlef, but the wrod as a wlohe. Amzanig huh?

Well Spoaken. Me coudda not sed it betta.

P.A.