Investigations on the thermal behaviour of CMC-based leading edges in hypersonic arc jet flows

Abstract

A generic leading edge model with a swept ceramic wing assembly was built, which enables to test leading edge samples made of the CMC materials C/C-SiC (non-oxide), OXIPOL and WHIPOX (both oxide). To measure the temperature evolutions, thermocouples were installed inside the model whereas an infrared camera and pyrometers were applied at the model’s outer surface. The model was investigated in DLR’s arc-heated facility L3K at a total enthalpy of 8.5 MJ/kg, Mach number of 7.8, varying angles of attack and wing inclinations. Furthermore, the effect of leading edge bluntness was studied. An analytical estimation was performed which was in good agreement with the maximum leading edge surface temperatures measured. The experiments conducted provide a sound data basis for the simulation of aerothermally loaded CMC leading edge structures. Within a first attempt, a fluid-structure coupled simulation was performed by FOI, based on a modal approach for the conduction model. Despite some deviations, results show that the temperature profiles are correctly depicted depending on the model’s angle of attack.