The U.S. Air Force is interested in developing hypersonic vehicles including reusable transport aircraft, cruise missiles, and unmanned systems. Hypersonic flight regimes result in multifaceted and very difficult design challenges that can be encapsulated into an aerothermoelastic problem, which is a complex interaction of structural, thermal, and aerodynamic mechanisms. When a flexible structural member such as vehicle skin panel is exposed to high-speed aerodynamic flow, various undesirable structural responses are possible. Proper panel design, guided by aerothermoelastic analyses is necessary to assure panel stability. Even for a stable panel, a temperature rise due to aerodynamic heat transfer can alter structural static and dynamic properties that can induce thermal stresses and cause panel deformation. Therefore, it is of critical importance to evaluate, both theoretically and experimentally, the aerothermoelastic performance of any proposed skin panel structure to be used on a hypersonic vehicle. Typically, coupled computational fluid dynamics (CFD) and finite element models are developed for fluid-thermal-structure interaction prediction, but high-quality experimental data is needed to validate these models. During the Phase II STTR effort, Global Aerospace Corporation and the California Institute of Technology will develop a proof-of-concept Hypersonic Experimental Aerothermoelastic Test (HEAT) system, conduct wind tunnel tests, and analyze results.
