Question 5

A turbojet engine is designed to operate at Mach 1.75 at an altitude of 35000 feet, where the ambient temperature and pressure are 219 K and 238 kPa, respectively. The engine has an overall compressor pressure ratio of 16 and its combustor exit temperature (Tt4) is 1750 K. Assume ideal conditions without losses and values of γ = 1.4 and R =287 J/(kg.K) for air.

Question 5a
For the turbojet engine, analyse the following values:

Question 5a(i)
Compressor exit total temperature Tt3.

Question 5a(ii)
Burner total temperature ratio τb.

Question 5a(iii)
Turbine total pressure ratio πt.

Question 5a(iv)
Exhaust Mach number M9.

Question 5b
Beginning from station 0 through station 9, illustrated by means of an H–K diagram, the dimensionless energy levels of the air as it passes through the above engine. Indicate the key values on the diagram.