Study on the diffuser structure for broadening flow width and numerical analysis in turbocharger centrifugal compressor

The diffuser jets water vapor structure was proposed to deal with the narrow flow range in vehicle turbocharger centrifugal compressor. In this article, the structured grids were meshed by ICEM, a high quality numerical model was established and the improved structure was investigated through multiphase phase numerical simulation with the help of fluent. Comparative analysis was conducted on the performance parameters of compressors under the original and improved structures, as well as the impact of diffuser jets water vapor structure on the flow performance of impeller and volute. The reasons for the improvement of compressor performance due to diffuser jets water vapor structure were analyzed. The result show that, the structure can restrain the expansion of eddy current in the volute, reduce the relative average speed in the impeller outlet, and improve the flow properties of the diffuser. The diffuser jets water vapor structure can increase the flow width and decrease the surge limit traffic, but with the flow range expansion the pressure ratio will decline.