Thermal Fluid-Structure-Interaction on a Flat-Plate Model in Hypersonic High-Enthalpy Flow

Kurzfassung

The focus of this degree thesis is the validation of a numerical environment for the coupled analysis of thermal protection systems and hot structures in interaction with a high-enthalpy hypersonic flowfield. The simulation of the thermal fluid-structure interaction on a ceramic flat-plate model was conducted by means of the TAU code developed at DLR for the calculation of the flowfield and with the commercial software ANSYS for the thermal response of the structure. The comparison with experimental results was achieved with tests in the high-enthalpy facility L3K of DLR in Cologne, which enables reaching a steady-state of the temperature distribution on the surface thanks to its rather long running-time. Coupled simulations were proved to more effectively reproduce the distributions of the thermal quantities on the surface of the concerned ceramic plate. Different flow models for the high-temperature gas and for the stream conditions were numerically investigated in order to understand their impact on the surface quantities, which was demonstrated to be generally not significant. The computations were shown to properly capture the temperature trend on the objective surface, but the temperature values were underpredicted. Because of that, further numerical investigations were performed in order to understand the impact of a full-catalytic surface and of an absolutely imperfect thermal contact between the components. In this way, a partially catalytic behaviour of the ceramics at such temperature levels and a non-perfect thermal contact between some structure parts were pointed out.