Effects analysis on aerodynamic noise reduction of centrifugal compressor used for gasoline engine

Abstract Miniaturization of gasoline engines equipped with turbochargers is an effective way to alleviate energy shortages and reduce emissions, whereas its compressor noise has become an issue. In order to research the effects of particular blade tip clearance and blade number on noise reduction of high-speed (100,500 rpm) centrifugal compressor used for gasoline engine under actual working conditions, the aerodynamic noise of a turbocharger compressor mounted on a passenger car engine is analyzed by using turbulence numerical simulation, aero-acoustic simulation and acoustic boundary element method (BEM). On the basis of the transient large eddy simulation calculation of the compressor flow field, the aero-acoustic analogy noise model and the acoustic boundary element method are used to calculate the aerodynamic noise of the compressor. The frequency spectrum of compressor BPF noise is analyzed, and the influence of different blade tip clearances and blade numbers on the broadband noise and BPF noise of the compressor at high speed is studied. The research of compressor related structural parameters on aerodynamic noise plays an important role in reducing compressor noise and improving compressor acoustic quality.