INTERACTION BETWEEN THE EXTERNAL FLOW ALO NG A POROUS-MEDIA AND THE EFFUSIVE FLOW INSIDE THE POROUS-MEDIA - APPLICATION TO COOLING OF WALLSSUBJECTED TO HIGH CONVECTIVE FLUXES

During effusion cooling of a porous plate, the refrigerant is simultan eously responsible for the internal cooling of the plate material and the protection of the downstream plate surface through the creation of an insulating film. The model developed in the present paper takes in to account the heat and mass transfer inside the porous matrix as well as the heat transfer in the flow region next to the surface affected by the interaction between the external flow of a high temperature flu id and the effusive flow of the cold fluid. The model is based simply on the energy conservation requirement and on a semi-empirical correla tion for one-dimensional flow inside the porous matrix. In order to ta ke into account the variation of thermal properties with temperature a nd pressure, the finite difference method was used to solve the result ing non-linear differential equations. The simple model was applied to the case of a plate subjected to very high temperature gradients and pressure differences. The fluid and plate material temperature profile s and the corresponding responding applied heat flux were then obtaine d.