Transitional shock/boundary-layer interaction on control surfaces of the IXV configuration

In the framework of the ESA FLPP program an experimental investigation of the aerothermodynamic phenomena on the IXV configuration during reentry phase has been conducted in the hypersonic wind tunnel H2K at DLR Cologne. To study the control behavior of the vehicle with flaps at different flight conditions, a variation of the flap deflection and the angle of attack have been applied. Tests have been carried out at Mach 8.7 and three different Reynolds number steps. Besides natural transition special devices were used on the model to trip the boundary layer. The test duration was up to 20 seconds. The model is made of a material with low thermal conductivity in order to measure the surface temperature distribution by means of IR thermography and to avoid any lateral heat dissipation inside the structure. Using this data the heat flux rate has been determined taking into account temperature-dependent material characteristics, assuming a semi infinite wall and radiative cooling to the environment. The flow topology has been analyzed using Schlieren images