槽道射流及端壁抽吸对角区分离的组合控制研究

Combined Control Effect of Slot Jet and End Wall Suction on Corner Separation

关键词:  压气机  叶片  叶栅  流动控制  角区分离  总压损失  端壁抽吸

Key words:  Compressor  Blade  Cascade  Flow control  Corner separation  Total pressure loss  End wall suction

摘要:

为优化叶片吸力面流动分离结构，探究对于角区分离更好的流动控制方法，以一大弯角扩压静子叶栅为研究对象，对叶片进行全叶高槽道结构处理，并在其基础上于槽道出口前进行端壁抽吸槽结构处理。在来流马赫数为0.7，来流攻角为-8°～6°工况下，对原型叶栅、全叶高开槽叶栅及组合流动控制叶栅进行性能计算及对比。结果表明：全叶高开槽方案能有效消除叶片吸力面叶中附面层分离，抑制角区分离，减小原型叶栅的总压损失，提高扩压能力。对比全叶高开槽方案，组合流动控制方案能更有效地抑制端壁二次流于槽道出口前在吸力面上的发展，进一步消除角区分离，优化近端壁区流场。因此，端壁抽吸加全叶高槽道射流的组合流动控制方案对于宽来流攻角范围具有更强的适应性，从而更有效地减小原型叶栅的总压损失，拓宽其可用攻角范围，提高叶栅的扩压能力。

Abstract:

In order to optimize the flow separation structure on the suction surface of the blade and explore a better flow control method for corner separation， a diffusion stator cascade with large camber angle is selected as the research object. Afterwards， the original blade is treated with a full-span slot structure， and on the basis of which the end wall suction slot structure is set up before the slot outlet. At last， the performance computations and comparisons of the original cascade， full-span slotted cascade and combined flow control cascade are carried out at the constant Mach number of 0.7， when the incidence angle range is -8°～6°. The results show that the full-span slotted scheme can effectively eliminate the midspan boundary layer separation on the suction surface of the blade and suppress the corner separation， reducing the total pressure loss and enhancing the pressure diffusing capability for the original cascade. However， compared with the full-span slotted scheme， the combined flow control scheme can better suppress the development of the end wall secondary flow on the suction surface before the slot outlet， hence further eliminating the corner separation and optimizing the flow field near end wall. Therefore， the combined flow control scheme of end wall suction and full-span slot jet has stronger adaptability to wide incidence range， it can more effectively reduce the total pressure loss for the original cascade， broadening its available incidence angle range and improving its pressure diffusing capability.