关键词: 压气机叶栅;组合抽吸;流动分离;壁面摩擦系数

Abstract: To explore the effectiveness and mechanisms of different forms of boundary layer suction (BLS) in controlling the separations in compressors, a linear compressor cascade, with separated flows on the whole span and three-dimensional separations over end wall corner, was researched based on the numerical simulation method. A total of eight suction schemes were set up. And the results show as follows: The effectiveness and mechanisms for flow separation control are different for different suction schemes, the control effectiveness is also different for the implement of suction at different development stages of separation. The separation at the suction surface and corner are reduced simultaneously under the control of suction scheme SS3 on suction surface near end wall, and the ‘C’ shape span-wise distribution of static pressure at the trailing edge near the suction surface prompts the transport of the low-energy fluid near the end wall to the mid-span which leads to the deterioration of the flow field near the mid-span. However, the span-wise distribution of static pressure is more uniform under the control of end wall suction and full span combined suction schemes resulting in the reduction of the transport of the low-energy fluid near the end wall to the mid-span. Based on these results, it can be seen clearly that combined BLS can more effectively control the flow separation inside the cascade, reduce the cascade loss and improve the flow capacity.

Key words: Compressor cascade;Combined boundary layer suction;Flow separation;Skin friction coefficient