Question

If an aircraft has maximum Mach number of 2 and bypass ratio of 0.71 then, what will be the weight of the engine? (Find the approximate value. Given thrust at takeoff is 10000 Unit.)

(a) 1058.5 unit

(b) 12000 unit

(c) 120

(d) 234.585 unit

This question was posed to me during an interview.

Asked question is from Propulsion topic in portion Propulsion and Fuel System Integration of Aircraft Design

Answer 1

The correct option is (a) 1058.5 unit

For explanation I would say: Given, Mach number M = 2, BPR = 0.71, Thrust T = 10000 unit

Now, Weight is given by, W = 0.063*T^1.1*M^0.25*e ^-0.81*BPR

W = 0.063*10000^1.1*2^0.25*e ^-0.81*0.71

W = 0.063*25118.86*1.189*0.5626 = 1058.5 u