the high pressure compressor of an aircraft engine has an inlet stagnation temperature of 372 k and stagnation pressure of 220 kpa. the overall pressure ratio is 10 and the air mass flow rate is 56 kg/s. the polytropic efficiency of the compressor is 0.90 and the stagnation temperature rise per stage must not exceed 30 k. calculate the number of stages required if dto is the same for all stages.