Uncertainty Propagation in Hypersonic Aerothermoelastic

This study sets the framework for uncertainty propagation in hypersonic aeroelastic and aerothermoelastic stability analyses. First, the aeroelastic stability of typical hypersonic control surface section is considered. Variability in the uncoupled natural frequencies of the system are modeled using beta probability distributions. Uncertainty is propagated to the flutter Mach number using the stochastic collocation approach. In addition, the stability of an aerodynamically heated panel located on a hypersonic vehicle is considered. Uncertainty is identified using CFD tools and it is shown that turbulence modeling has a significant effect on the prediction of the heat flux distribution and transition location. The uncertainties identified are propagated through the system and their effect on the flight of the vehicle is determined. For both cases, uncertainty is treated using stochastic collocation, a relatively new approach that is shown to be very efficient. Nomenclature a Normalized elastic axis location positive aft from midchord A,B Coefficients for beta distribution Aj Fitting coefficient