The flow mechanism of the shock structure and secondary flow control in transonic centrifugal compressors with leading edge sweep

Abstract

Limitations still exist in the research on the effects of leading edge sweep on transonic centrifugal compressors. The lack of understanding of this mechanism also leads to confusion regarding the magnitudes of the performance changes that occur due to the use of leading edge sweep. According to a detailed numerical simulation verified by experiments on two different compressors, the effect and flow mechanism of leading edge sweep on transonic centrifugal compressors were investigated in detail to alleviate the confusion as clearly as possible. The conclusions show that leading edge sweep has different impacts on shock waves at different positions; a forward sweep leading edge can weaken the strength of the shock wave in front of the leading edge, while a backward sweep leading edge can weaken the strength of the passage shock wave that is swallowed in the blade passage. The improved compressor performance attributed to leading edge sweep is due to the weakening of the shock waves and the interaction between the shock waves and the secondary flow of the inducer tip. Furthermore, the intensity of the inducer tip secondary flow influences the potential for improved performance induced by using sweep leading edges in transonic centrifugal compressors. This study provides a valuable reference for applying leading edge sweep to existing transonic centrifugal compressors or future advanced centrifugal compressor designs.