Leading edge vortex dynamics on finite aspect ratio swept wings exhibiting large amplitude oscillations

Stall flutter, a fluid–structural interaction driven by dynamic stall, has primarily been studied as a two-dimensional flow phenomenon. However, recent investigations suggest that wing sweep, which induces spanwise flow and cross-flow instability, significantly influences the leading-edge vortex (LEV) formation. This paper investigates the effects of wing sweep on stall flutter instabilities using a cyber-physical approach, combining experiments and high-fidelity simulations. Results reveal that increasing sweep reduces flutter amplitude and delays instability onset by weakening the LEV. The spanwise flow induced by sweep promotes LEV shedding and breakdown, leading to a stabilizing effect. Prescribed and responding motions exhibit similar dynamics, with minor differences attributed to nonlinearities in the fluid–structure interaction. Detailed analysis of the flow field and unsteady aerodynamic forces provides insights into the complex interplay between sweep, LEV development, and aeroelastic stability.