A gas turbine used to drive a water pump. The gas turbine has two shafts. The turbine axial compressor is driven by high pressure turbine through the first shaft. The low pressure turbine is direct coupled to the water pump. The speed of the high pressure turbine is higher than the speed of the low pressure turbine. The water pump discharge 287 m3 /hr at 170 bar. The pump suction pressure is 5 bar. The pump efficiency is 65%. The compressor pressure ratio is 12:1. The fuel used in the turbine is propane has a calorific value of 44.5 MJ/kg, with air to fuel ratio 60:1. Neglect the pressure drop in the turbine combustion chamber. The combustion products specific heat at constant pressure is 1.15 KJ/Kg K while for air is 1 KJ/Kg K. The isentropic efficiencies of high, low pressure turbines and compressor are 85%, 82.5% and 80.7% respectively. The ambient pressure and temperature are 1 bar and 27oC respectively,

calculate: 

 1- The pressure and temperature of the exhaust gases at the outlet of the high pressure turbine

2- The air flow rate through the axial compressor

3- The gas turbine thermal efficiency