基 于 因 果 网 络 分 析 的 扩 压 叶 栅 波 浪 形 前 缘控 制 机 理

Separation and vortex motion are key factors limiting the performance improvement of compressors，while the wavy leading-edge can effectively expand the working range of the compressor. This study implements the wavy leading-edge shape on the diffuser cascade，and uses a multi-objective optimization algorithm to construct a wavy leading-edge that significantly reduces the stall point loss at the expense of minimum design point performance. A data mining method，causal network analysis，is used to investigate the flow mechanism of the internal flow field of the dif⁃ fuser cascade with variation in the wavy leading-edge control parameters. The optimization results show that the strength of the leading-edge vortex pairs increases as the amplitude-wave ratio decreases，and that the stall point loss can be significantly reduced at the expense of minimum design point performance with the amplitude-wave ratio range within 0. 05⁃0. 15. The causal network model and flow field analysis verify that，from the vortex motion perspective，the wavy leading-edge generates leading-edge vortex pairs，and the development of the leading-edge vortex pairs weakens that of the channel vortex and trailing-edge vortex flow through different ways；from the separation perspec⁃ tive，the wavy leading-edge weakens the loss caused by the corner region separation by changing the leading-edge airflow inhomogeneity and secondary flow energy and improving the low-energy fluid blockage.