Effect of Surface Motion on Background Unsteadiness in Turbulent Shock/Boundary-Layer Interactions

A sufficient understanding of shock-dominated aeroelastic phenomena is critical to the routine fielding of high-speed flight vehicles. However, the role of the inherently unsteady flow in the aeroelastic response and the impact of the structural dynamics on the turbulence is poorly understood. To this end, implicit large eddy simulations (ILES) are used to explore the effects of wall motion on turbulent shock/boundary-layer interactions and to gain insights into the modification of inherent flow unsteadiness. In this work, the first eigenmode of a clamped-clamped beam is chosen to represent the structural dynamics observed in relevant experimental campaigns. Flow statistics are computed relative to the structural dynamics using phase and spanwise averaging, which is formalized using a triple decomposition of the flow. Comparisons across phase-mean streamwise velocity and surface pressure profiles present insights into the change in the bulk flow topology. In particular, a shift in the shear layer, mean separation shock position, and reattachment point is observed. Modifications to the flow unsteadiness are addressed using phase-local, second-order statistical moments. The surface motion modulates the background wall pressure and streamwise velocity fluctuations near the panel trailing edge and foot of the separated shear layer. Additionally, an analysis of the phase-local energy transfer between the phase-mean flow and background unsteadiness is performed. Changes in energy transfer due to deceleration and phase-mean shear are observed near the separation point and downstream of flow reattachment.