Analysis of the Effects of Circumferential Groove Casing Treatment on a Transonic Axial Flow Compressor

A circumferential groove casing treatment was designed,the effects of circumferential casing treatment on the performance and flow field of a transonic axial flow compressor rotor was numerically investigated by performing a 3-D steady-state Navier-Stokes analysis.The results show that,the calculation agrees well with the experiment.The circumferential groove casing treatment is able to extend the stall margin of the compressor rotor effectively with slight penalty on the adiabatic efficiency.The stall mass flow and the peak adiabatic efficiency are degreased by 11.5 percent and 0.82 percent respectively.The analysis of the internal flow field indicates that,the key mechanism of circumferential groove to extend the stall margin is the suppression of blockage zone resulted from the interactions between the tip leakage flow and passage shock,another key mechanism to extend the stall margin is the remove of blockage zone resulted from boundary layer radial vortex.