b$)$ Airbus A$230$ engines are based on the gas turbine principle which operates with

$75\%$ regenerator effectiveness and $80\%$ compressor and turbine efficiency. Air

enters the compressor at $100k\frac{N}{m^2}$ and $27C.$ The pressure ratio is $5$ and the

turbine inlet temperature is $984C.$ Considering all of processes to be ideal and

neglecting the mass of the fuel added to the air,

i$)$ Determine the cycle thermal efficiency, and

$[8$ marks$]$

ii$)$ Sketch the process on a temperature entropy diagram.

$[5$ marks$]$