Question

The propeller efficiency depends on the advance ratio and power coefficient.

(a) True

(b) False

The question was posed to me in class test.

My question is from Power Producing Power Plant topic in chapter Aircraft Force Systems and the Equations of Motion of Aircraft Performance

Answer 1

Right choice is (a) True

The best explanation: The propeller efficiency depends on the propeller advance ratio and power coefficient. Propeller advance ratio is given by J=\(\frac{V}{nD}\) where J is propeller advance ratio, V is true airspeed, n is rotational speed and D is propeller diameter. Also the pressure coefficient is given by CP=\(\frac{P}{\frac{\rho n^3D^5}{2}}\) where CP is pressure coefficient, ρ is density, P is shaft power, n is rotational speed and D is propeller diameter.