Fluid Structure Interaction on a Generic Body-Flap Model in Hypersonic Flow

A numerical investigation of a generic reentry vehicle flap configuration at hypersonic speed is presented, which includes considerations of the generic hinge line gap and the outer edges of the flap. Numerical solutions were obtained with a Navier–Stokes code and were coupled via a surface interpolation routine to a structural solver. Two- and three-dimensional solutions were compared for the generic flap model, consisting of a forebody and a body flap deflected 20 deg relative to the forebody with a gap between them. Presented are computational results for a freestream Mach number of 7.3 and an angle of attack of 15 deg with both open- and closed-gap configurations, which are compared to available experimental data. Numerical error, either from the code or the grid, is assessed with the impact of any error on the magnitude of the heat fluxes and the associated gradients. The three-dimensional solutions predict that a strong outflow from the center of the model to the outer edges takes place over the model surface, impacting the flow topology significantly. This was verified with comparison to the experimental results. Temperature peaks predicted by stand-alone computational fluid dynamics solutions were not observed in the experimental data. The investigations confirmed that this is due to strong coupling effects between fluid and structure. Heat conduction into and inside the structure leads to significantly reduced surface temperatures in critical regions.