Enriched Piston Theory for Expedient Aeroelastic Loads Prediction in the Presence of Shock Impingements

This study assesses the robustness and efficiency of the enriched piston theory approach for modeling aeroelastic loads in the presence of impinging shocks. Both stationary and oscillating shock impingements are considered in two- and three-dimensional flows, with benchmark solutions provided by Euler and Reynolds-averaged Navier-Stokes models. For prescribed surface oscillations, the approach yields good agreement with unsteady computational fluid dynamics. The approach also captures shock-induced limit-cycle oscillations, indicating that the unsteady component of the flow is effectively captured using a quasi-steady, inviscid flow model. The computational cost of enriched piston theory is orders of magnitude less than that required for computational fluid dynamics, making the approach viable for long time record response prediction. However, the results highlight that the accuracy of enriched piston theory degrades for increasing modal activity, which induces unsteady viscous effects not captured by the model. Additionally, the efficacy of the quasi-steady flow assumption in enriched piston theory depends on the ratio of the shock-induced separation length to surface length.