Torque and Rotary Engines

A question for you all. There have been many comments about the torque produced by rotary engines and it it well and truly modelled in Red Baron 3D. The question is why couldn't it be cancelled out in the rigging of the wings? If the wings were rigged with a slight flex to oppose the torque then surely you wouldn't have to fly with the joystick held to left all the time. I realize this would not change the torque effect on turns but it would have made the aeroplanes less tiresome to fly!

Yuor thoughts please.

Cheers

Dave

If you were to make a torque counter it would have to be movable because at different speeds the effects of the torque counter would be more or less apparent. So it would make sense to have a flap on one of the wings that you could trim at different speeds.

Some pilots took advantage of the torquing characteristics of their planes to do manuevers that other planes without these characteristics couldn't perform. I bet many of the experienced camel pilots, after months of adjusting to the characteristics, if a solution was offered to the torquing question, would choose rather to stick with the anomole.

To all,
Iv'e heard alot of talk about torque in WW1 a/c.
But what I have not heard anyone mention is the effect of "P-factor".
This is the force of thrust generated by the prop against the vertical stabilizer or rudder. This effect, combined with torque is what makes an a/c swing to the left or right on takeoff.
I'm sure that most all of these old planes, with their eight foot props, suffered from this effect more so than modern light planes.

Just a little FWI.
C.Grube

C.Grube,

The force you describe as causing yaw on take-off is accurate, but is not P-Factor. P-Factor is the difference in thrust between the upward moving and downward moving propellor blades at varying angles of attack (of the aircraft) and engine speed.

Note: Angle of Attack is the relative angle of the wind stream in relation to the camber line of an airfoil. So it can relate to the angle of the wings to the movement of the aircraft (angle of attack of the aircraft) or the angle of the relative wind to the propellor blades (which are cambered like a wing).

The angle of attack of the individual prop blades is a combination of the velocity and direction of the aircraft through the air (the angle of attack of the aircraft itself) and the velocity of the propellor as it rotates. Because the upward and downward moving prop blades are moving in opposite directions (obviously), at an AIRCRAFT angles of attack greater than zero (unless an aircraft is pushing the nose over, it generally flies at a positive angle of attack), if you draw out the vectors and add them, you find that the downward moving prop blade has a greater angle of attack than the upward moving prop blade, causing a difference in thrust, and thus a yawing moment. Most modern prop airplanes have clockwise rotating props when viewed from the rear, which means that p-factor creates a left yaw, requiring right rudder to compensate.

This force change whenever you change the airspeed of the aircraft, the pitch of the aircraft, the speed of the engine/prop, or the pitch of the prop (in variable pitch propellors), requiring varying amounts of rudder to counteract it.

Does anyone know if WWI aircraft engines were mostly clockwise rotating also?

Hans,
I stand corrected!

C.Grube

Several aircraft were in fact designed with torque reduction in mind, primarily by making the span of the wings or controls different port and starboard. In addition, the rigger could dramatically affect the amount of torque felt by varying the rigging of the aeroplane, altering dihedral and angle of incidence.

Not all engines, including rotaries, turned the same way. Then, of course, you have the Siemens-Halske contra-rotary, where the propeller turned one way and the motor the other. This was primarily to reduce the torque effect of the powerplant.

Hi,guys.We had a fairly detailed discussion on this subject a couple of months ago re the swinging and torquing of Camels.The four factors that come into play in making an aeroplane swing and torque are the Slipstream Effect,the Asymmetric Blade Effect(or P Factor),the Gyroscopic Effect and,finally,Torque.Of these,the effect of the Slipstream Effect is reduced on bi/triplanes because of the venetian blind effect of the wings.Where we had a major question mark the last time was how,with all the foregoing factors,the Camel would turn/spin viciously to the RIGHT when the engine/prop swung right,which would have made the airframe swing LEFT.No logical,scientific answers were given which makes me wonder if the Camel was RIGGED to swing right.This is not too far-fetched,considering the fact that although most of its weight was in the first four or five feet from the nose,it was rigged tail-heavy.

My understanding is that most rotaries turned to clockwise (when viewed from behind), while stationary engines like the Hisso and Wolseley Viper turned their props counter-clockwise.

My previous reply was incomplete. If I recall correctly, the Fokker Dr.1 had a larger port than starboard aileron in order to compensate for the gyro effect of the rotary engine.

I'm also under the impression that it was the gyroscopic force that was the primary motivator in swinging rotary-powered machines to the right and down. Of course, it could be just that the writers I've read have been using "gyroscopic" imprecisely to describe a combination of forces.

Hello, Mike,

Hate to burst your bubble on the DR1 triplane, but both ailerons are identical. That information was probably based on an old photograph of Dr1, 144/17
which was captured in Jan. 1918. This a/c had an early type aileron on the starboard side, and an enlarged aileron of the later pattern on the port. (Profile publications #55).

C.Grube