Performance of a Jet Pump used to Test the Heat Exchanger of TEJAS Aircraft

The atmospheric air ingested into gas turbine unit is not absolutely pure.It always contains Solid or liquid aerosols,moisture in liquid or vapour form, and some times harmful gaseous substance such as hydrogen sulphide,sulphur dioxide,nitrogen and chlorine compound etc.Their sources are soil dust,river,sea and atmospheric moisture,pollen and seeds,waste products generated by traffic and industrial enterprises.These impurities of atmospheric air adhere to the compressor blading and annulus area of the gas turbine, affecting the engine performance.The axial flow compressor fouling greatly influences the gas turbine unit performance.The fouled axial compressor has deteriorated aerodynamic quantities,which causes the decrease in the air mass flow through the engine and decrease in surge margin and compressor efficiency.Simultaneously there is drop in compressor pressure ratio due to reduced gas mass flow through the gas turbine.The net effect leads to decrease in the gas turbine unit output and to increase in the specific fuel consumption.This report describes the method to evaluate the performance deterioration of axial compressor stage due to fouling