Role of turbulence on high-speed aeroelastic behavior of a cantilever plate

Abstract

Accurate and efficient prediction of high-speed aeroelastic behavior is greatly hampered by insufficient understanding of the role of multi-scale fluid features on structural dynamics. In this work, we use a combination of scale-resolving and modeled simulations to evaluate the significance of capturing coupling with the broadband turbulent pressure fluctuations on prediction of the aeroelastic response. A Mach 2 turbulent flow separating from a cantilever plate is considered at nondimensional dynamic pressures of $\lambda =100$ and 150. The fully coupled Large-Eddy Simulations (LES) predict sustained oscillations, with larger amplitudes and modal coalescence for the higher $\lambda$ and shock-induced separation on the cantilever top surface. The significance of capturing dynamic feedback between the broadband turbulence and structural compliance is highlighted through aeroelastic response prediction comparisons between LES and URANS. Here, wall pressure fluctuations are extracted from LES data about undeformed and time-mean deflected states of the cantilever and separately added to coupled URANS simulations. The results indicate that key aspects of the aeroelastic behavior can be recovered by URANS in conjunction with an uncoupled turbulent load. However, clear differences in response frequency and instantaneous amplitude remain present compared to LES, suggesting missing coupled phenomena from the URANS prediction.