I posted the same question before but the answer was wrong. Answers are written at the bottom of the question. Please ch
Posted: Fri Jul 01, 2022 6:40 am
Question 3 A single stage centrifugal compressor which has an impeller with an overall diameter of 60cm is used in an Auxiliary Power Unit (APU) of an aircraft. The compressor rotates at 12,000 rpm and compresses 29 kg/s of air. The eye inner radius is 64mm and the outer radius of the eye is 150mm. If the air inlet temperature and pressure are 280 K and 335 kPa respectively, and there is no pre-swirl or losses in the inlet duct, calculate: (a) the blade inlet angle at root and tip of the eye; (b) the eye tip Mach number; Assuming the slip factor to be 0.9, an isentropic efficiency of 0.85 and the work done factor to be 1.03, calculate: (c) the pressure ratio obtainable; (d) the power required by a turbine to drive the compressor. (Approximate answers: droot = 58.2°, atip = 34.52°, Meye tip = 0.692, Pressure Ratio = 3.23, Power input-3.82MW)