Cary/Bax,
I am in the same boat with Cary, in that I have a good physics/engineering background but the aerodynamics stuff is new to me.
I tend to agree with Bax that when you are accelerating (the take off run or pulling a vertical) the swirling air from the prop is the main effect. And this is what is being corrected for in the right thrust. The trimming charts I have seen adjust the right thrust to pull a straight vertical.
ORIGINAL: jcmccorm
I don't quite understand the torque effect with respect to rolling the airplane left and causing it to turn left. It seems like the axial torque would definitely change with throttle setting and want to roll the plane but it would take a lift vector component in the "left" direction for the plane to want to turn left (ie banked left) and I imagine we always subconscously correct for this.
Cary
The torque effect (I think -- Bax, please correct me if I'm going astray) is seen more as changes in trim at cruise speed. At cruise the prop should not be swirling the air behind it so much as it corkscrews through the air near pitch-speed (pitch*rpm). If you trim the plane to do a straight level hands-off pass at half throttle, then make a hands-off pass at full throttle the plane will veer left. I've been told this is due to the torque effect. My guess is the roll rate from the change in torque is only a few degrees per second, so in a 3-6 second pass it looks like a gently banked turn to the left. After 600 yards or so the pilot has to turn the plane around.
Computer radios let you mix some rudder into the throttle. Is this usually used for correcting cruise trim or for making take-offs easier? Seems that if you used it for take-off (acceleration effects) it would mess-up the cruise trim when changing throttle settings.
Carl