Question

The net propulsive thrust is given by _________

(a) FN=FG-Dm

(b) FN=FG+Dm

(c) FN=FG*Dm

(d) FN=FG/Dm

The question was asked during a job interview.

I'm obligated to ask this question of Thrust Producing Power Plant topic in division Aircraft Force Systems and the Equations of Motion of Aircraft Performance

Answer 1

Correct option is (a) FN=FG-Dm

For explanation: The net propulsive thrust is given by FN=FG-Dm where FN is net propulsive force, FG is gross thrust and Dm is momentum drag. The net propulsive force is the difference between the stream force entering and leaving the engine. Flow due to intake flow is known as momentum drag. The gross thrust is the thrust produced at the exit of the nozzle.