Abstract: 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.

Key words: transoniccentrifugalcompressor, inletbendpipe, guidefin, numericalsimulation