Question

Determine the propeller efficiency if propeller velocity is 300ft/s and thrust of 1320 lb. Given bhp is 800.

(a) 90%

(b) 0.03%

(c) 0.895%

(d) 0.09%

This question was posed to me in an online interview.

I'm obligated to ask this question of Propulsion in section Propulsion of Aircraft Design

Answer 1

Correct option is (a) 90%

Easy explanation: Propeller efficiency = (thrust*velocity) / (bhp*550) = 1320*300/ (550*800) = 0.9 = 0.9*100 % = 90%.