Question

What should be the value of speed power coefficient if velocity of propeller is 12 unit and power is 100 unit? Given rps is 25.

(a) 1.372

(b) 2.35

(c) 8.97

(d) 9.79

The question was asked during an online interview.

Question is from Propulsion in portion Propulsion of Aircraft Design

Answer 1

Correct answer is (a) 1.372

Best explanation: Speed power coefficient = Velocity*(density / power*rps^2)^0.2 = 12*(1.225/100*25*25)^0.2 = 12*0.1144 = 1.372.