为改善压气机叶栅内的分离流动、优化气动性能，以仿生凹凸前缘叶栅为研究对象，基于数值方法分析吸力面特殊流动形成的原因，研究零攻角工况下凹凸前缘叶栅的流动特性，并基于涡系变化和附面层结构的分析，总结了凹凸前缘叶栅的流动控制机理。研究结果表明：由于前缘压力梯度作用使凹凸前缘叶栅形成了特殊的流向涡对，在下游向两侧发展形成特殊的三维分离结构，挤压局部流管收缩，提高了流动附着性并重组附面层结构，降低了角区分离范围且避免了大尺度集中脱落涡的形成，改善了下游流动。探索了凹凸前缘叶栅的典型旋涡模型，并基于对流动控制机理的理解，给出若干优化方案，得到叶栅气动性能提升，其中WFB-2-9叶栅相比原始叶栅总压损失系数降低了10.47%。

In order to improve the separated flow in compressor cascade and optimize the aerodynamic performance,taking the bionic concaveconvex leading edge cascade as the research object,the reason for the formation of special flow on the suction surface is analyzed based on numerical method,the flow characteristics of concaveconvex leading edge cascade at zero angle of attack are studied,and the flow control mechanism of concaveconvex leading edge cascade is summarized based on the analysis of vortex system change and boundary layer structure.The results show that a special pair of streamwise vortices is formed in the concaveconvex leading edge cascade due to the leading edge pressure gradient action,and a special threedimensional separation structure is developed and formed on both sides of the downstream,by squeezing the local flow tube to contract,the flow adhesion is improved and the boundary layer structure is reorganized,the corner separation range is reduced and the formation of largescale concentrated shedding vortices is avoided,so as to improve the downstream flow.The typical vortex model of concaveconvex leading edge cascade is explored.Based on the understanding of the flow control mechanism,several optimization schemes are given,which can improve the aerodynamic performance of the cascade,the total pressure loss coefficient of WFB-2-9 cascade is reduced by 10.47% compared with the original cascade.

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国家自然科学基金区域创新发展联合基金（U20A20298）；国家科技重大专项（2017-II-0006-0019，2017-I-0009-0010）