Blade Meridional Profile Optimization for Novel High-Pressure Ratio Centrifugal Compressor Design Using Numerical Simulations

In this research, a comprehensive numerical investigation of high-pressure ratio turbocharger centrifugal compressor impeller has been carried out. The objective is to study the influence of varying blade meridional contour on the total pressure ratio and isentropic efficiency from stall to choke using (3D) numerical simulations. The transonic SRV2 compressor developed by DLR (German Aerospace Center) has been used as the test case. Numerical simulations have been executed using Reynolds Averaged Navier Stokes (RANS) based k-ɛ model to predict turbulence. Y plus is kept 35 for the structured mesh near the boundaries. In first part, calculations were carried out for design conditions; speed of 50,000 1/min and mass flow rate of 2.546 kg/s to compare the results of ANSYS CFX with experimental data in the design procedure. Numerical simulations overpredicts the experimental data by 9 percent. In second part, blade meridional contour and blade thickness have been changed to see its effect on performance parameters of centrifugal compressor at high rotational speed. Being the important parameter, appropriate blade meridional design can improve pressure ratio and efficiency of centrifugal compressor. The novel design improved the stall margin by 1.1 percent while operating range from stall to choke has been upgraded by 1 percent.