K-1

An airplane supercharger consists of a turbine and a rotary compressor. It is receiving exhaust from the engine at 15 psia and 1000 F, and compressing air from 5 to 15 psia, the initial temperature being 60 F. What is the lowest efficiency it can have and still do the job?

K-2

1. Sketch the aircraft turbojet cycle on TS coordinates indicating the effect of inefficiencies in all apparatus except the diffuser.

2. The diffuser (ram) of a turbojet engine has an efficiency of 100 per cent. Estimate the temperature and pressure of air leaving the ram when it is flying at sea level at a speed of 500 mph.

3. What is the relationship between turbine work and compressor work in a turbojet engine?

4. What air flow is required to produce a thrust of 3,000 lb at an air speed of 500 mph and a jet exit velocity of 1,600 fps?

K-3

At a certain section of an air stream the stream the Mach number is 2.5, the stagnation temperature is 560 R, and the static pressure is 0.5 atm. Assuming that the flow is steady, isentropic, and follows one-dimensional theory, calculate (all at the point where the Mach number is 2.5) ( a) temperature, ( b) stagnation pressure, ( c) velocity, ( d) specific volume, and ( e) mass velocity.

K-4

A jet plane flies at an altitude of 5,000 ft where atmospheric temperature is 40 F. An observer on the ground notes that he...