Question

If manufacturer’s thrust loss requirement is 3% and engine has mass flow of 20 unit then, determine how much bleed mass flow can be used?

(a) 0.3 unit

(b) 0.4 unit

(c) 0.8 unit

(d) 0.9835 unit

The question was posed to me during a job interview.

Question is from Propulsion in division Propulsion of Aircraft Design

Answer 1

Correct option is (a) 0.3 unit

Explanation: Bleed correction factor C can be approximated as 2 when it is not mentioned in the question.

Bleed mass flow = Thrust loss*Engine mass flow / C = 0.03*20/2 = 0.3 unit.