基于端壁涡流发生器的压气机叶栅角区分离控制研究

Investigation of Corner Separation Control for CompressorCascade Based on Endwall Vortex Generator

关键词:  压气机叶栅  涡流发生器  横向二次流  角区分离  流向涡

Key words:  Compressor cascade  Vortex generator  Crosswise secondary flow  Corner separation  Streamwise vortex

摘要:

为研究被动式涡流发生器抑制压气机叶栅横向二次流以控制角区分离的作用，设计了在叶栅内部端壁处加装涡流发生器的控制方案，采用数值模拟的方法，详细分析了叶栅流场特性。结果表明：涡流发生器可以有效地抑制叶栅内部横向二次流，改善角区流动，在最佳控制方案中，总压损失系数下降8.1%；放置于叶栅内部的涡流发生器能阻挡气流的横向流动，其尾部产生的流向涡与横向迁移的端壁附面层相互作用，抑制了通道涡向吸力面的发展，并将主流高能流体卷入角区，增加角区流体动量；涡流发生器的长度和高度都会影响流向涡的强度，流向涡的涡核高度与涡流发生器高度一致，最终的控制效果由涡流发生器的长度和高度共同决定，只有当它们被合理选择，控制方案才能获得最佳控制效果。

Abstract:

In order to study the passive vortex generator to suppress the crosswise secondary flow of the compressor cascade to control the separation of the corner zone, a control scheme for installing the vortex generator at the inner end wall of the cascade is designed. With the method of numerical simulation, the cascade flow field characteristics are analyzed in detail. The results show that VG can suppress the crosswise secondary flow effectively, which results in the improvement of corner region flow. In the optimum control scheme, the total pressure loss coefficient decreases by 8.1%. The VG placed inside of cascade can resist the crosswise flow and the streamwise vortex generated by VG can interact with the boundary layer in near end wall region, resulting in limiting the development of passage vortex from pressure to suction side. Meanwhile stream-wise vortex entrains high energy fluid to suction side corner region to increase momentum of corner fluid. Furthermore, the intensity of streamwise vortex are influenced by both length and height of VG, and the height of streamwise vortex core is same as the height of VG. Thus, the final control effect is decided by both length and height of VG. Only when they are chosen reasonably, the optimal effect can be achieved.