Model Reduction of Computational Aerothermodynamics for Hypersonic Aerothermoelasticity

A primary challenge for aerothermoelastic analysis in hypersonic flow is accurate and efficient computation of unsteady aerothermodynamic loads. This study examines two model reduction strategies with the goal to enable the use of computational fluid dynamics within a long time-record, dynamic, aerothermoelastic analysis. One approach seeks to exploit the quasi-steady nature of the flow by using steady-state computational fluid dynamics to capture primary flow features, and simple analytical approximations to account for unsteady effects. The second approach seeks to minimize the computational cost of steady-state computational fluid dynamics flow analysis using either kriging or proper orthogonal decomposition-based modeling techniques. These model reduction strategies are assessed, both individually and combined, in the context of a three-dimensional hypersonic control surface. Results computed over a wide range of operating conditions and reduced frequencies indicate that when combined, the considered approaches yield an aerothermodynamic model that is tractable within a dynamic aerothermoelastic analysis, and generally has less than 5% maximum error relative to computational fluid dynamics.