PDA

View Full Version : torque effect again



XyZspineZyX
09-30-2003, 01:47 AM
i think im ******ed... it's about 2 o'clock in the morning down here in italy and i simply can't stop thinking about this damn thing...

german planes:
prop turning clockwise as seen by the pilot, aircraft tends to yaw to the left, can't understand why my fw then tends to bank to the right when airborne though

okie, now let's go through it with basic physics, let's use the dread right hand rule... prop turning to the "right", hence my plane is subject to a torque that would make it spin in such a way my right shoulder would rise above the other one, momentum vector using the right hand rule is easily determined, it's pointing towards me, but slightly pointing down to the ground because of the rear wheel still being on the ground (the engine axis is pointing slightly upright)... that's the vector component that's supposed to make your plane yaw to the left... thumb down... and then I sadly look at my fingers showing the way it should turn to, to the RIGHT goddddammmmm!!! but nay it moves to the left, and i must say that's reasonable after all,the prop is "pushing" the blade to the right hence it gets pushed to left... still i cant understand why my physical argument wont hold water anybody out there willing to lend me a hand to understand where my fault lies? thanks in advance

i almost forgot, with russian planes it works the other way round /i/smilies/16x16_smiley-happy.gif

XyZspineZyX
09-30-2003, 01:47 AM
i think im ******ed... it's about 2 o'clock in the morning down here in italy and i simply can't stop thinking about this damn thing...

german planes:
prop turning clockwise as seen by the pilot, aircraft tends to yaw to the left, can't understand why my fw then tends to bank to the right when airborne though

okie, now let's go through it with basic physics, let's use the dread right hand rule... prop turning to the "right", hence my plane is subject to a torque that would make it spin in such a way my right shoulder would rise above the other one, momentum vector using the right hand rule is easily determined, it's pointing towards me, but slightly pointing down to the ground because of the rear wheel still being on the ground (the engine axis is pointing slightly upright)... that's the vector component that's supposed to make your plane yaw to the left... thumb down... and then I sadly look at my fingers showing the way it should turn to, to the RIGHT goddddammmmm!!! but nay it moves to the left, and i must say that's reasonable after all,the prop is "pushing" the blade to the right hence it gets pushed to left... still i cant understand why my physical argument wont hold water anybody out there willing to lend me a hand to understand where my fault lies? thanks in advance

i almost forgot, with russian planes it works the other way round /i/smilies/16x16_smiley-happy.gif

XyZspineZyX
09-30-2003, 03:57 AM
sera. I know what your talking about. I have a physics degree. Its newton's third law. Action reaction. The torque effect is due to the mounting of the engine. Right hand rule does not apply to the prop turning,it applies to the direction of the engine mounting. The aircraft will rotate in the opposite direction of the prop turning. Use newton's third law.

Ciao amico.

http://www.cbrnp.com/profiles/insignia/italy/incocca-tende-scaglia.jpg
Saluti!
<center>http://www.bloggerheads.com/mash_quiz/images/mash_henry_blake.jpg (http://www.bloggerheads.com/mash_quiz/)</center>

XyZspineZyX
09-30-2003, 05:07 AM
its not JUST torque effect to be considered especially on takeoff.

think about

- spiral prop wash hitting the tail plane
- gyroscopic effects when sudden changes occur .. for example when the tail lifts on take-off
- the effect when rolling of one wheel digging into the ground harder than the other

<center> http://groups.msn.com/_Secure/0SQDLAtUWiWZ3BKw19!aryp7v3C1h1DuNwpHOOuqhlraGSyMAY KiPEOZAA1OBgsLu*Sa0UQ2my0PiFyvNkJ5K7Clsoy7yNtEvOXY nHDuPNiotpZACY2oJxw/aircraftround.jpg </center>