Shock Wave Turbulent Boundary Layer Interaction Over a Flexible Panel

Abstract

Shock wave turbulent boundary layer interaction (SBLI) over a flexible panel is investigated by performing large eddy simulations (LES). The supersonic flow is at Mach 4 and Reynolds number per unit length of 2.375 × 10 7 (/m). The incident oblique shock with the shock strength p 3 /p 1 ≈ 8.5 and shock angle σ ≈ 30 deg impinges near the mid-chord length of the panel. The panel aspect ratio and thickness, normalized by its length a, are b/a = 1.377 and h/a = 0.003, respectively. First, we examine the baseline SBLI on a rigid flat surface, where the strong adverse pressure gradient due to shock impingement leads to a large region of separated flow (L se p ≈ 23δ in ), and a characteristic low-frequency unsteadiness associated with the separation bubble. Second, we inspect the fully coupled fluid-structure interaction (FSI) between the SBLI and flexible panel, where the interplay results in sustained oscillations. The fully coupled FSI simulations are performed by means of our recently developed FSI solver framework, where we externally couple the standalone finite difference flow and finite element structural solvers. The panel response and flow physics are elucidated by performing modal analyses, in terms of the proper orthogonal decomposition (POD) and dynamic mode decomposition (DMD), identifying the dominant flow frequencies and panel vibration modes as well as the dynamic coupling between the panel wall pressure and deflection.