Manipulation of Shock/Boundary-Layer Interactions in Hypersonic Inlets

Possibilities to manipulate shock/boundary layer interactions are demonstrated with regard to an application for hypersonic inlets. Experiments on generic models have been carried out in the hypersonic wind tunnel H2K of DLR at Mach number 6 and laminar flow conditions. Experimental results were validated by numerical flow simulations using a 2D finite element scheme. An analytical method has been developed for the pre-design of bleed configurations. In case of shock induced boundary layer separation it could be shown, that the implementation of bleed leads to a reduction of the separation bubble thickness by almost 50%. Further experimental investigations dealt with the achivable reduction of the heat loads on the wall surface depending on the amount and the position of the boundary layer bleed. These examinations were extended to three-dimensional corner flows. By this, favorable design parameters for a boundary layer bleed set-up were found. Finally, the results obtained using the generic models were transferred to a hypersonic inlet model. There the application of a correctly designed and positioned bleed system showed a significant increase of the attainable total pressure recovery