叶尖单侧倒圆对扩压叶栅叶顶间隙流动的影响

A method of compressor cascade blade tip leakage flow control was presented. By using a small-scale fillet structure in the pressure side of the blade tip region, the flow condition in the tip clearance of the diffuser cascade was improved. The effects of blade tip fillet on the aerodynamic performance of compressor cascade were investigated by numerical method. Through analysis of the control effects of three different tip fillet structures (3%, 4%, 6% of the maximum blade thickness), the simulation showed that the blade tip fillet structure can weaken the tip separation vortex with the decrease of total pressure loss coefficient of tip clearance passage and affect the vortex system structure in the region of tip clearance. The method showed a good ability to improve the flow conditions in the blade tip region and undermined the effect of blockage in blade tip passage. However, an increase in the leakage mass flow rate with a loss for the efficiency was observed because of the mixing of leakage flow and main flow. The conclusion shows that the appropriate blade tip fillet structure could improve the aerodynamic performance and the fillet radius of 3% of the maximum blade thickness has a good effect compared with other radiuses.