端壁造型与附面层抽吸耦合流动控制对压气机叶栅的性能影响

Effects of Profiled End Wall and Boundary Layer Suction Coupled Flow Control on Compressor Cascade Performance

关键词:  压气机叶栅  角区分离  端壁造型  附面层抽吸  优化造型

Key words:  Compressor cascade  Corner separation  Profiled end wall  Boundary layer suction  Optimazition profiling

摘要:

为改善轴流压气机性能，抑制角区分离，采用数值模拟方法探究端壁造型（PEW）与附面层抽吸（BLS）两种流动控制措施在不同工况下对高负荷压气机叶栅的气动性能影响。使用神经网络作为代理模型，采用多目标遗传算法进行全局寻优，选取得到的5种最优端壁造型结构，与3种不同弦长位置的抽吸缝进行组合。结果表明：兼顾设计工况及近失速工况叶栅气动性能，采用吸力面70%弦长位置抽吸与通道前中部下凹、近压力面上凸的造型组合最优。设计工况下，附面层抽吸抑制了弦长中部转捩泡的生成，有效降低了尾迹损失，此时最优组合减小了12.7%的总压损失。近失速工况下，端壁造型通过控制端区横向二次流，缓解堵塞，抑制了角区分离进而降低尾迹损失，此时最优组合减小了15.5%的总压损失。

Abstract:

To improve the performance of axial flow compressors and suppress the corner separation， profiled end wall（PEW）and boundary layer suction（BLS）are combined to explore the influence of two control methods on the aerodynamic performance of high-load compressor cascades at different conditions by using numerical simulation. Neural network is used as surrogate models and multi-objective genetic algorithm is used for global optimization. Five optimum end wall cases are combined with three kinds of suction slots in different chord length positions. The results show that taking into account the aerodynamic performance of the cascade in design condition and near-stall condition， the combination of suction slot at the 70% chord length of the suction side and the concave front and middle part of the passage， and the convex shape near the pressure surface are optimal. At the design condition， the boundary layer suction suppressed the generation of transition bubbles in the middle of the chord length， and effectively reduced the wake loss. At this time， the optimal combination reduces the total pressure loss by 12.7%. At the near stall condition， the profiled end wall method can effectively control the end wall secondary flow， improve the passage blockage， suppress the corner separation and reduce the wake loss. At this time， the optimal combination reduces the total pressure loss by 15.5%.