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Acta Aeronautica et Astronautica Sinica ›› 2023, Vol. 44 ›› Issue (19): 128336-128336.doi: 10.7527/S1000-6893.2023.28336

• Fluid Mechanics and Flight Mechanics • Previous Articles     Next Articles

Flow control mechanism of diffuser cascade with wavy leading⁃edge based on causal network analysis

Jiezhong DONG, Wuli CHU(), Haoguang ZHANG, Bo LUO, Song YAN   

  1. School of Power and Energy,Northwestern Polytechnical University,Xi’an 710129,China
  • Received:2022-11-28 Revised:2022-12-23 Accepted:2023-03-13 Online:2023-10-15 Published:2023-04-14
  • Contact: Wuli CHU E-mail:wlchu@nwpu.edu.cn
  • Supported by:
    National Natural Science Foundation of China(52076179)

Abstract:

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 diffuser 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 perspective, 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.

Key words: compressor, separation and vortex motion, wavy leading-edge, multi-objective optimization, causal network analysis

CLC Number: