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Acta Aeronautica et Astronautica Sinica ›› 2023, Vol. 44 ›› Issue (22): 128519-128519.doi: 10.7527/S1000-6893.2023.28519

• Fluid Mechanics and Flight Mechanics • Previous Articles     Next Articles

Effects of porous wall on secondary instability of optimal growth streaks in high speed boundary layers

Yutian WANG1, Jianxin LIU2, Xiaokun WANG1, Xiaoming LI1()   

  1. 1.Aviation University of Air Force,Changchun 130022,China
    2.School of Mechanical Engineering,Tianjin University,Tianjin 300072,China
  • Received:2023-02-01 Revised:2023-03-17 Accepted:2023-04-06 Online:2023-04-17 Published:2023-04-14
  • Contact: Xiaoming LI E-mail:27657939@qq.com
  • Supported by:
    National Natural Science Foundation of China(92052301)

Abstract:

Boundary layer transition is a key fundamental theoretical problem in the design of hypersonic vehicles. High intensity environmental disturbances leads to subcritical transition upstream of the mode instability region, triggered by secondary instability of optimal growth streaks. To assess the effect of the porous wall on the subcritical transition, this paper studies both super/hypersonic flat-plate boundary layer flows. Based on the adjoint parabolized stability equations, an optimization system as well as a numerical method is developed. The three-dimensional boundary layer flow with streaks resulted from the optimal disturbances of nonlinear evolution is used as the new base flow for the bi-global stability analysis. The result shows that, the secondary instability modes in the frequency range of the second modes are stabilized by the porous wall, while those in the frequency range of the first modes are destabilized, with the turning frequency close to the local synchronization frequency. Such regularity is helpful for the arrangement of porous coating in engineering applications.

Key words: subcritical transition, optimal disturbance, bi-global stability analysis, porous wall, parabolized stability equation

CLC Number: