RESEARCH ON SEEPAGE MODEL OF POROUS MEDIA SURFACE IN HIGH-SPEED BOUNDARY LAYERS

Due to the severe aerodynamic heating of high-speed aircraft, the surface heat flux rise sharply with the increase of Mach number, thus requiring thermal protection for the aircraft surface. Transpiration cooling, as an effective active thermal protection method, has become a current research hotspot, and the problem of porous medium seepage is one of the key issues. This study focuses on the coupled problem of porous medium seepage and high-speed boundary layer flow. In the porous medium region, the volume averaging method is used to average the porous medium microstructure, obtaining the compressible Darcy-Forchheimer-Brinkman (D-F-B) equations. With some transformation, the D-F-B equations are converted into a form similar to the Navier-Stokes (N-S) equations with additional source terms. Based on this, a single domain computational frame between the high speed main flow and porous media seepage is developed and numerical simulations of porous media Couette flow, porous medium seepage in high-speed boundary layer flows, etc. are carried out to explore the validity of the porous media model described by the D-F-B equations. The results show that the porous media model can simulate flow characteristics of the porous media, and the obtained results are in good agreement with the analytical solution and DNS results. Temperature fields of the porous medium based on the local thermal non-equilibrium hypothesis are more accurate than those based on the local thermal equilibrium hypothesis. Compared to the DNS of porous medium, the seepage model based on D-F-B equations can significantly reduce the number of grids, making it suitable for massive numerical simulation applications.