High-enthalpy test environments, flow modeling and in situ diagnostics for characterizing ultra-high temperature ceramics

Ultra-high temperature ceramic materials and composites under development as nose-tip and wing leading edge components for hypersonic flight vehicles must operate in extreme aerothermal heating environments. The performance of ultra-high temperature ceramics for this application is ultimately evaluated using high-enthalpy, long duration flow facilities that simulate the reactive gas environment encountered in hypersonic flight. In this paper, we describe the test environments generated by two types of these ground test facilities – subsonic inductively coupled plasma tunnels and supersonic arc-jet tunnels – and discuss the important roles of computational fluid dynamics modeling and in situ optical diagnostics for interpreting test results from a materials science perspective.