高原环境下离心式压气机通用特性研究

针对高原环境下工作的车用柴油机涡轮增压器，对离心压气机的通用特性进行了理论分析，采用数值模拟方法研究了高原进口条件及低雷诺数对于压气机特性的影响。通过改变不同条件下压气机的进口参数，采用折合流量和折合转速的方法对压气机的性能进行对比分析；讨论了高原环境下进口温度和进口压力的变化对压气机折合特性的影响，研究了低雷诺数对压气机内部流场的影响，得到了高原条件下压气机通用特性的变化规律。结果表明，高原条件下压气机进口压力减小导致雷诺数降低，引起压气机内部流动发生变化，是压气机性能下降的主要原因。

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.