Formula for Aircraft Propeller Thrust

tilopa

I'm trying to understand thrust for a real world application. I found this formula:

T= pi / 4 x D(squared) x (v+V1/2) x p x V1

Where:

T thrust [N]
D propeller diameter [m]
v velocity of incoming flow [m/s]
V1 additional velocity, acceleration by propeller [m/s]
P density of fluid [kg/m³]
(air: = 1.225 kg/m³, water: = 1000 kg/m³)

I understand how increasing the propeller diameter would increase the "amount" of air and therefor increase thrust. But the equation does not account for the increased pitch angle of the propeller blades. Intuitively (and by Newton's Third Law of Motion) if you increase the angle of the blade against the air you will be pushing more air (greater "amount" of air), correct? So, does anyone have an equation for thrust that includes the propeller angle. Or an equation that I can use that includes pitch angle to replace the D2 value in this equation?

Thanks.

CWatters

I think it does. Changing pitch would change the V1 term.

I think if you find one that has pitch in it explicitly it will also have unknown constants that relate to the blade design. For example the torque won't be zero at zero pitch. It might not be a maximium at max pitch either.

CWatters

Looks like a good read...
http://www.free-online-private-pilot...odynamics.html

http://www-mdp.eng.cam.ac.uk/web/lib...ler/prop1.html

tilopa

Thanks, I'll check out those links.