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Acta Aeronautica et Astronautica Sinica ›› 2023, Vol. 44 ›› Issue (15): 528963-528963.doi: 10.7527/S1000-6893.2023.28963

• Fluid Mechanics and Vehicle Conceptual Design • Previous Articles    

Effects of viscous dissipation on wall heat flux in high-enthalpy turbulent boundary layer

Junyang LI, Pengxin LIU, Ming YU, Dong SUN, Siwei DONG, Xianxu YUAN()   

  1. State Key Laboratory of Aerodynamics,Mianyang  621000,China
  • Received:2023-05-05 Revised:2023-06-05 Accepted:2023-07-03 Online:2023-07-10 Published:2023-07-07
  • Contact: Xianxu YUAN E-mail:yuanxianxu@skla.cardc.cn
  • Supported by:
    National Key R&D Program of China(2019YFA0405200);National Natural Science Foundation of China(12272396);National Numerical Windtunnel Project

Abstract:

During the high-speed flight of the aircraft, the head shock wave will strongly compress the incoming flow, which will lead to a sharp increase in gas temperature and stimulate the high-temperature non-equilibrium effect. The high-enthalpy turbulent boundary layer is formed by coupling high temperature non-equilibrium effects and turbulence, which makes the formation mechanism of wall heat flux on the aircraft surface more complex. In this paper, based on the internal energy conservation equation, the heat flux decomposition formula suitable for the high-enthalpy turbulent boundary layer is derived. The heat flux generation mechanism of the high enthalpy zero-pressure gradient plate turbulent boundary layer is analyzed, focusing on the effect of viscous dissipation on the generation of wall heat flux. The results show that viscous dissipation is the main source of heat flux generation, and the high temperature non-equilibrium effect increases the contribution of viscous dissipation near the wall. The viscous dissipation can be divided into two parts: average and fluctuating ones, which are mainly distributed in the near-wall region and logarithmic region, respectively. The two parts of viscous dissipation have a significant effect on the wall heat flux, and the contribution of the average viscous dissipation on the wall heat flux is about twice that of the fluctuating viscous dissipation.

Key words: high-temperature non-equilibrium effect, turbulent boundary layer, direct numerical simulation, decomposition of wall heat flux, viscous dissipation

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