压气机叶栅中不同安装角肋式涡流发生器的数值研究

Numerical Study of Rib Type Vortex Generator with Different Stagger Angles in a Compressor Cascade

为了研究肋式涡流发生器对压气机叶栅角区分离流动的控制效果,本文采用数值方法,对不同安装角度的涡流发生器方案进行了详细的研究。研究结果表明:肋式涡流发生器根部与顶部会产生两个流向涡,安装角不同时顶部流向涡会明显变换旋向,从而导致其与角区分离流的相互作用过程出现较大的不同。负安装角的涡流发生器对角区流动的作用优于正安装角方案,能较为明显地减小角区低能流体的堆积,但研究结果也表明,需合理选择负安装角,当涡流发生器与来流夹角较小时,涡流发生器产生的流向涡强度较低,无法与吸力面/端壁处的低能流体进行有效掺混,而当角度过大时流向涡强度迅速增强,与分离涡的作用方式发生较大变化,下端壁处损失剧增。

To research the control effect of rib-type vortex generator on corner separation flow in a compressor cascade, vortex generators with different stagger angles were studied through numerical simulation in this paper. The results show that there are two streamwise vortexes produced at the top and bottom position of rib-type vortex generator. The rotating direction of streamwise vortexes will change when the stagger angle changes and the interaction process between the streamwise vortex and corner separation flow will show a different feature. The vortex generators with negative stagger angle work better than the positive ones, which can obstruct the accumulation of corner flow better. The results also show the negative stagger angle value should be carefully chosen. When the angle value is too small, streamwise vortexes are too wake to be mixed with the suction side/end wall low-energy fluid effectively. When the angle value is too large, the streamwise vortexes are too strong and the interaction with the separation vortexes changes significantly, which introduce extra losses.