A diesel engine is fitted with a turbocharger that comprises a radial flow compressor driven by a radial flow exhaust gas turbine. The gravimetric air-fuel ratio is 20:1; the air is drawn into the compressor at a pressure of 1 bar and at a temperature of 15 degrees C. The compressor delivery pressure is 2.0 bar. The exhaust gases from the engine enter the turbine at a temperature of 510 degrees C; the gases leave the turbine at a pressure of 1.05 bar. The isentropic efficiencies of the compressor and turbine are 65% and 75% respectively.
Treating the exhaust gases as perfect gas with the same properties as air and assuming a mechanical efficiency of 100%, calculate the following:
a) The temperature of the gases leaving the compressor
b) The pressure ratio across the turbine