Question

Which of the following is a power-producing powerplant?

(a) Turbojet

(b) Turbofan

(c) Rocket

(d) Piston engine

I got this question in homework.

My query is from Power Producing Power Plant in section Aircraft Force Systems and the Equations of Motion of Aircraft Performance

Answer 1

The correct choice is (d) Piston engine

For explanation I would say: The two forms of powerplant used in aircraft propulsion are thrust-producing and power producing. A thrust-producing powerplant is the one whose propulsive force is obtained by increasing momentum of the airflow through the engine. A power-producing powerplant is the one whose propulsive force is obtained from shaft power by propeller. Examples of thrust-producing powerplant are turbojet, turbofan and rocket. Examples of power-producing powerplant are gas turbine and piston engine.