Fully coupled nonlinear aerothermoelastic computational model of a plate in hypersonic flow

A recent structural model of a plate is extended to include a nonuniform temperature differential that varies in time using a modal expansion. The nonlinear structural plate model with first-order piston theory aerodynamics and cavity dynamics is coupled with the heat equation to form a single system of dynamical equations for the fluid-structural-thermal system. The heat flux from the boundary layer to the plate is modeled using the temperature reference method. A computational scheme is formulated by linearizing the heat flux in terms of two variables: the local aerodynamic downwash due to plate motion and the local wall temperature. The proposed linearization produces a local force equivalent for the pointwise heat flux and substantially simplifies the time-marching scheme of the coupled equations. The model is correlated with results from a recent supersonic wind-tunnel experiment conducted at Air Force Research Laboratory (AFRL). It is found that when a nonlinear response is expected in an experiment (for example, flutter that reaches limit cycle oscillation or a large static buckled deformation), the in-plane boundary stiffness should be measured before the wind-tunnel experiment to fully characterize the experimental model. The heat flux linearization error is quantified, and the modal convergence of the temperature differential is investigated.

Duke Scholars

Author Earl H. Dowell Thomas Lord Department of Mechanical Engineering and Materia ...