进气弯管对离心压气机特性影响及弯管结构优化

离心压气机进口常采用弯管导流进气，弯管中的二次流动会导致压气机进口气流出现畸变，影响压气机的气动性能。针对这一问题，通过数值仿真与台架试验相结合的方式，研究弯管对离心压气机特性的影响规律及产生机理。在此基础上提出在弯管内增加导流肋片的改进方法，并进行数值仿真与试验验证。研究结果表明：在压气机进口增加弯管后，压比和效率特性都发生了一定程度的恶化，在大流量工况时，性能的下降尤其显著；采用内部布置导流肋片的弯管结构，能够进一步规范弯管内部气流的流动特征，改善压气机进口流动状态，使流动变得相对均匀，从而使性能得到全方位的提升。

Effect of Inlet Bend Pipe on the Centrifugal Compressor Performance and Its Optimization Design

Bend pipe is often used for air guidance at centrifugal compressor inlet, in which the distortion of inlet flow may be caused by secondary flow. For this problem, the influence law and mechanism of bend pipe on centrifugal compressor performance were studied through numerical simulation and bench test. On that basis，an optimization design method of adding the guide fins into the bend pipe was put forward and verified through simulation and bench test. The simulated and test results show that the pressure ratio and efficiency are deteriorated to a certain extent by adding the guide fins into the inlet bend pipe, which is more obvious at the chock point of compressor. The new bend pipe with guide fins can regulate the characteristics of the inner flow in the pipe. The improved flow state makes the flow at the compressor inlet become relatively uniform, thus improving the performance of compressor.