Experiments on shock-boundary layer interaction and cooling efficiency in a transpiration cooled model scramjet

Transpiration cooling systems are a promising approach to handle the high wall temperatures and heat loads generated in supersonic combustion ramjets (scramjets). The German Aerospace Center DLR has conducted experiments to investigate the applicability of transpiration cooling systems in scramjets and the phenomena resulting out of the interaction between a wedge/flame holder and coolant secondary flow. Results with nitrogen as coolant for different sintered porous materials, different blowing ratios and different boundary conditions with and without wedge are shown. A detailed analysis using i.a. optical Schlieren investigations is presented. Phenomena like choking and shock-coolant plenum feedback are addressed. Further research is discussed and concretized.