Numerical Simulation And Experimental Study On Aerodynamic Noise Of Exhaust-Gas Turbocharger Compressor

In order to increase efficiently the power of diesel engines with lower fuel consumption,compressors with high pressure ratio and rotate speed are increasingly applied to the exhaustgas turbocharger of marine diesel engines, with the aim of promoting the superchargeefficiency. However, with the increase of the rotate speed of compressors, its noise producedduring the process of working has been becoming obvious gradually. The study concerningthe mechanism of production and characteristics of the noise is the foundation of reducing it.Therefore, in this article, a numerical simulation prediction about and an experimental studyon the characteristics of the aerodynamic noise inside a certain type of radial compressors,which used in marine diesel engine exhaust-gas turbocharger, under rated working conditionwere made.First, in this article, I established a precise three-dimensional geometric model ofcompressor, and divided successfully its calculation domain grid with complicated flowpassages, and analysed its inner steady flow field under the rated working condition, usingthe CFD software FLUENT as the terrace of emulation. Secondly, based on the simulationresult of the steady flow field of compressors under rated working condition, a numericalsimulation prediction about the characteristics of the space division of the broadband noiseinside compressors and the frequency spectrum of the discrete noise produced at thejunction of the flow passages of the compressors rotor and the diffuser was maderespectively.Finally, experimental study on the noise at the entrance of compressor underrated working condition was conducted. To obtain the noise spectrum without muffler bymaking respectively the experimental study on the characteristics of the noise at theentrance of the exhaust gas turbocharger compressor under the rated working condition andthe acoustical transmission loss of muffler.The findings indicated that this article enabled us to have an overall understanding ofthe aerodynamic noise inside compressors by means of the combination of numericalsimulation prediction and experimental study, which provided a good reference for us tomake a further optimal design of the structure of compressors and reduction of its noisewhile working.