Research on non-dimensional characteristics of centrifugal compressor under altitude environment

A vehicular diesel turbocharger working in altitude environment is studied. Based on the theory analysis of non-dimensional characteristics of centrifugal compressor, the effects of plateau conditions and low Reynolds number on compressor characterisitics are investigated using numerical simulation method. The performance of compressor is analyzed with the use of non-dimensional flow rate and non-dimensional speed by changing compressor inlet parameters. The influences of the changes in inlet temperature and pressure on the equivalent characteristics of compressor are discussed, and the change rule of compressor non-dimensional characteristics under altitude environment was obtained. The results show that the reduction in compressor inlet pressure leads to low Reynolds number on plateau to make the change of compressor internal flow, which is the main reason to reduce the comprossor performance.