RESUMO

The effectiveness of a transpiration-cooled thermal protection system for a hypersonic reentry vehicle consisting of porous material is numerically analyzed with the new concept of coupling of outer free stream and inner flow within the porous matrix. This analysis is more effective in estimation of surface temperature and heat flux to the system compared with previous methods. The transpiration of coolant fluid has great cooling effectiveness as a result of decrease of surface temperature and heat flux, as transpired fluid injected into the outer flow cools the surface as well as creates a moderate temperature gradient near the surface. Increase of back face pressure corresponding to increase of transpiration mass flow causes the lower surface temperature and smaller heat flux. The cooling effectiveness per mass transpiration rate based on decrease of surface temperature is improved by smaller porosity, which shows the superiority of smaller porosity material for practical use.