高负荷对转压气机尾迹涡对叶顶泄漏流的影响

The Impact of Wake Vortices on the Tip Clearance Flow in a High-load Counter-rotating Compressor

采用三维非定常数值模拟方法,针对高负荷对转压气机低压转子尾迹脱落涡对高压转子叶顶泄漏流的影响开展研究。研究发现:低压转子尾迹涡以“对涡”的形式在高压转子通道中输运,顺时针与逆时针旋向尾迹涡间隔分布,对叶顶泄漏流与主流交界面法向动量产生不同影响,进而使叶顶泄漏流与主流交界面形状呈现波浪形。设计工况下,尾迹涡会使叶顶泄漏流与主流交界面的位置偏向吸力面以及后移结尾激波位置进而后移二次泄漏流产生的位置,减小压力面与吸力面结尾激波入射点之间弦长区域叶顶泄漏流与轴向的夹角,提高相应弦长区域叶顶泄漏流的轴向速度,减小高压转子叶尖区的堵塞,降低二次泄漏流产生的损失,进而提升高压转子叶尖区的等熵效率。

A three-dimensional unsteady numerical simulation method was used to investigate the effect of wake shedding vortices of the up-stream rotor on tip leakage flow of the down-stream rotor in a high-load counter-rotating compressor.The results show that the wake vortices of the up-stream rotors transport in the passage of the down-stream rotor with the form of"counter vortices".The interval distribution of the clockwise and counterclockwise wake vortices has different effects on the normal momentum of the interface of the tip leakage flow and the mainstream,thus making it present wave shape.Under design condition,the position of the interface of the tip leakage flow and the mainstream will be shifted to the suction surface and the position of the passage shock wave moves backwards,then the position of the secondary leakage flow will be shifted backward by wake vortices.The angle between tip leakage flow and axial direction will be reduced in the chord-length region where is between the incident point of the passage shock wave on the pressure surface and the suction surface respectively,while the axial velocity of tip leakage flow in this chord-length region will be increased,and the blockage of the high-pressure rotor in tip region will be reduced.Moreover,the loss caused by secondary leakage flow will be reduced,and then the isentropic efficiency of the high-pressure rotor will be improved in the tip region.