Numerical investigation of aerodynamic load on the impellers of centrifugal compressor with leakage flow

Abstract

Based on computational fluid dynamics (CFD) simulation, this study investigates the effect of leakage flow on the performance of centrifugal compressor, which helps to showcase the flow phenomenon considering the leakage flow and the aerodynamic load on the impellers. We consider four types of compressor models including the normal stage with hub and shroud leakages (SWT), the normal stage with hub leakage (SWH), the normal stage with shroud leakage (SWS), and the normal stage without leakages (SOT)). The results indicate that the leakage flow obviously affects the compressor performance, especially the flow field around the leading/trailing edge of the impeller. The aerodynamic load at the leading/trailing edge of the impeller was obtained for the models through unsteady simulation. The dominant frequency and the pulse amplitude obtained by Fast Fourier transforms revealed that the main frequencies of the aerodynamic load present different distributions under different leakage flows.