An aircraft engine is fitted with a single-sided centrifugal compressor. The aircraft flies with a speed of 230 m/s at an altitude where the pressure, pa = 0.23 bar and the temperature, Ta = 217 K (note these are static values). The intake duct of the impeller eye contains fixed vanes which give the air prewhirl of 250 at all radii. The inner and outer diameters of the eye are 18 and 33 cm respectively, the diameter of the impeller periphery is 54 cm and the rotational speed is 270 rev/s. Estimate the stagnation pressure at the compressor outlet when the massflow is 3.60 kg/s.
Neglect losses in the inlet duct and fixed vanes, and assume that the isentropic efficiency of the compressor,ηcs= 0.80. Take the slip factor, σ= 0.9 and the power input factor,φ = 1.04.