2 Calculate the mass flow and the annulus area at the rotor outlet for an axial compressor stage The flow enters the rotor without swirl at a Mach number of 0 4 at a stagnation pressure of 200 kPa and a stagnation temperature of 370 K in an annulus of area 0 17 m The axial velocity is constant across the rotor but the flow leaves at 30 6 degrees to the axial direction The stagnation pressure at the rotor outlet is 230 kPa and the stagnation to stagnation polytropic efficiency to this point is 0 94 Use properties of air as k 1 4and Cp 1008 9 J Kg K