Mach 6 Aerothermoelastic Experiment for an Inclined, Compliant CFCF Panel With Buckling

The mechanical and thermal loads on an airframe, particularly when traveling at supersonic and hypersonic velocities, can cause its skin panels to buckle. The altered shape and induced internal stress may affect the aerodynamics of the vehicle and its structural response. Modeling and simulating the complex, non-linear coupling of high-speed fluid-thermal-structural interactions (FTSI) of skin panel s becomes more challenging when taking into account the effects of buckling. This work analyzes the FTSI of a compliant, rectangular aluminum panel with clamped-free-clamped-free (CFCF) structural boundary conditions under Mach 6 flow conditions in the University of Southern Queensland’s Hypersonic Wind Tunnel (TUSQ). Additionally, the panel is tested under four buckled states: non-buckled at room temperature (Tw/T0 = 0.56) and at 190 °C (Tw/T0 = 0.87), mechanically buckled at room temperature, and thermally buckled via restricted thermal expansion from 175 °C to 190 °C. Buckling the panel decreased the frequency at which the panel oscillated while loaded aerodynamically (“wind on’) and after the flow ended (“wind off”). Thus buckling the panel had a “softening” effect on its dynamic response. The data also provided evidence that while the aerodynamic loading tended to have a “stiffening” effect on the panel at room temperature for the non-buckled and mechanically buckled cases, the opposite effect was generally observed when the panel was heated to 190 °C for the non-buckled and thermally buckled cases, particularly in the α = -5° configuration. These results elucidate some of the underlying physics involved with FTSI. Furthermore, this analysis combined with the experimental database can be used to validate high-speed numerical simulations of FTSI.