不同攻角下端壁射流旋涡控制扩压叶栅分离流动研究

Effects of End-Wall Vortex Generator Jet on Flow Separation Control in Compressor Cascade under Different Angles of Attack

关键词:  扩压叶栅  端壁射流式旋涡发生器  流动分离  攻角

Key words:  Compressor cascade  End-wall vortex generator jet  Flow separation  Angle of attack

摘要:

为了研究端壁射流旋涡对扩压叶栅分离流动及性能的影响，采用数值模拟的方法，对不同攻角下带有端壁射流的50°折转角扩压叶栅进行了研究。结果表明:具有最优射流结构的旋涡发生器有效减弱了叶栅角区分离，零攻角下出口总压损失降低了8.9%；随着攻角的上升，射流对扩压叶栅气动性能的改善越显著；射流产生的旋涡可阻挡端壁低能流体向吸力面的迁移，并将主流流体卷入角区，角区流体动量增加、流动分离减弱，但旋涡与端壁二次流的掺混使得10%叶高以下的损失略微增大；射流参数决定了射流旋涡与吸力面的相对位置以及旋涡强度，对射流控制栅内流动分离效果有重大影响，需合理选择。

Abstract:

The application of end-wall vortex generator jet (VGJ) to a compressor cascade with a 50° camber angle for flow separation control was studied using numerical simulation. The results show that under zero-incidence， the optimum VGJ can weaken the flow separation of the corner region effectively and lead to 8.9% descent of the total pressure loss at outlet. With the angle of attack rising， the jet also improves the aerodynamic performance of compressor cascade obviously. The jet vortex entrains high energy fluid to the corner region， resulting in the increase of corner fluid momentum and the alleviation of flow separation. However， the loss in the region below 10% blade height increases slightly due to the mixing between jet vortex and secondary flow near the end-wall. The distance between jet vortex and suction surface and the intensity of jet vortex decided by the jet parameters are important for the effect of jet on flow separation control in the compressor cascade. It is suggested that the jet parameters be chosen reasonably.