Question

An axial-flow compressor rotor at the pitchline has a radius of rm = 0.3 m. The shaft rotational speed is ? =4500 rpm. The inlet flow to the rotor has zero preswirl and the axial velocity is Cz1 = Cz2 = Cz3 = 180 m∕s. The rotor has a 50% degree of reaction at the pitchline. The stage adiabatic efficiency is nearly equal to the polytropic efficiency ?s ≅ ec = 0.90. Assuming the inlet total temperature is Tt1 = 288 K and Cp = 1.004 kJ∕kg ⋅ K, calculate

a) rotor specific work at rm

b) stage loading ? at rm

c) flow coefficient at rm

d) rotor relative Mach number at the pitchline, M1r,m

e) stage total pressure ratio at the pitchline

Answer 1