In a jet engine rotor the high pressure axial compressor rotates at a speed of 14750 rpm. the overall stagnation pressure ratio due to compression is 9.1. it was recorded that the air flows at a rate of 15.7 kg/s. the stagnation properties at the inlet are 205 kpa and 450k. the poly-tropic efficiency of the compressor is 92%. assume the mean radius of the compressor is constant and equal to 0.25m. calculate the total-to-total isentropic efficiency of the compressor. estimate the number of stages required, if the stage loading to be less than 0.4. why was the values of the area used to calculate t2?