Effects of Wall-Temperature Conditions on Effusion Cooling in a Supersonic Boundary Layer
The influence of effusion cooling through discrete holes on a laminar Mach 2.67 boundary layer is investigated using direct numerical simulation. It is found that the wall condition (isothermal, adiabatic, or radiative-adiabatic, with neglected heat conduction within the wall) has a very strong influence on the vortex systems that are generated by the holes and thus also on the cooling features. The transfer of results from short-duration isothermal shock-tunnel experiments to the more realistic radiative-adiabatic situation is difficult. In addition to trying to establish a coolant film at the wall, a significant increase of the wall shear should be avoided in order to not increase the heat flux into the wall.