Flow Characteristic of Transonic Centrifugal Compressor with Free-Form Sweep Impeller at Leading and Trailing Edges

The free-form sweep method was used to improve the leading and trailing edges of impeller blade on a transonic centrifugal compressor, and corresponding numerical simulation and bench test were also carried out. The results show that in full speed range, the front free-sweep at the leading edge of the blade makes the impeller more suitable for the transonic flow at the inlet, which effectively improves the shape of shock wave. Additionally, the front free-sweep at the leading edge also increases the chock flow rate, reduces the shock loss and improves the efficiency of the centrifugal compressor. On the other hand, the free-sweep at trailing edge can increase the work area of the blade outlet, which reduces the low-energy flow structure formed by the combination of trailing edge clearance flow and the mainstream flow separation and leads to an increase of the pressure ratio and a stability improvement of the compressor. In the end, the improved transonic centrifugal compressor with freeform sweep impeller at leading and trailing edges was manufactured and then tested on a compressor test bench. It is found that the numerical results agrees well to the test results. © 2021, Editorial Office of the Transaction of CSICE. All right reserved.