Aerodynamic performance and noise investigation of lean design in turbocharger centrifugal compressor blade

As marine centrifugal compressors evolve toward higher pressure ratios, larger mass flow rates, and lower noise emissions, optimizing impeller design has become a key focus of research. Among various design parameters, lean characteristics play a critical role in aerodynamic design. However, their influence on compressor aerodynamic performance and noise generation remains inadequately understood. This study presents a systematic investigation into this issue. First, the aerodynamic performance and noise of a marine centrifugal compressor were predicted using numerical simulations and subsequently validated through experiments. Various lean configurations were then developed to assess their impact on overall compressor performance and internal flow structures. Finally, the Power Spectral Density (PSD) analysis of fluctuating pressure was conducted to explore the mechanisms by which blade lean affects noise characteristics. The results indicate that blade lean significantly affects both aerodynamic performance and noise, with tip lean exhibiting a more pronounced effect than root lean. A positive tip lean at the leading edge enhances aerodynamic performance but increases noise levels, whereas a negative tip lean at the trailing edge effectively reduces noise with a slight performance gain. Specifically, a leading-edge positive tip lean angle of 3° improves compressor efficiency but raises noise by 1.5 dB, while a trailing-edge negative tip lean angle of 12° reduces noise by 3 dB with a slight performance improvement. Based on these findings, a blade configuration that combines a positive tip lean at the leading edge and a negative tip lean at the trailing edge is proposed, achieving a 1% improvement in aerodynamic efficiency and a 2.8 dB(A) reduction in noise—offering a promising solution for high-efficiency, low-noise compressor blade design.