Numerical and experimental investigations of centrifugal compressor BPF noise

Centrifugal compressor noise has become an issue in marine diesel engine turbochargers in recent years. Compressor noise is difficult to predict due to the complexity of the internal flow and has thus been the focus of numerous studies. Compressor blade passing frequency (BPF) noise in relation to impeller rotation is considered one of the dominating noise sources in centrifugal compressor noise, it can govern the overall compressor noise level. This study developed a numerical method combining the computational fluid dynamics (CFD) and acoustic boundary element method (BEM) to predict compressor BPF noise. The compressor unsteady flow characteristics were first calculated using the RNG k-epsilon turbulence model to obtain the fluctuation pressure. Then, the fluctuation pressure was used to acquire the aeroacoustic sources, and the compressor BPF noise was subsequently calculated with the BEM. The compressor BPF noise at three different compressor rotating speeds were calculated, and the simulation results were validated using the experimental data, the results indicated that the numerical method is sufficiently accurate to predict compressor noise. (C) 2019 Elsevier Ltd. All rights reserved.