A Compressor Wheel Design for Noise Reduction Due to Pressure Gradient in an Automotive Turbocharger

Abstract In the most industries that manufacture compressors, it is very common to encounter noise issues on the compressor wheel while its operation. This noise is likely due to a pressure gradient along the compressor blades with inlet air flowing through them. This paper presents experimental and numerical investigations of noise reduction for the compressor wheel of an automotive turbocharger by modifying its geometry such as inlet area, inlet and outlet beta angles. The numerical model includes a one-dimensional aerodynamic analysis of the inlet and outlet operating conditions and describes meridional design of the compressor wheel. The design parameters include compressor inlet diameter, trim ratio, throat area, inlet and outlet beta angles, etc. Structural analysis on modal and centrifugal stress verifies the model reliability. CFD analysis of compressor models calculates total and static pressures at inlet and outlet domains, mass flow rate, and aerodynamic efficiency. The experimental data agree well with the numerical predictions while evidences noise reduction from the design method used in this paper. The newly designed compressor wheel meets the desired goals such as maximum efficiency at specific flow rates and rotational speeds and successfully reduces noise due to fluid instability.