Vortical similarities across laminar and turbulent extreme gust encounters

This study uncovers a striking similarity between massively separated laminar and turbulent flows that develop over a square wing during extreme vortex gust encounters. The evolving large-scale, vortical core structures responsible for significant transient lift variations exhibit remarkable similarity across ${\textit{Re}}=600$ and 10 000. The formation of these structures is attributed to a substantial gust-induced vorticity flux produced at the wing surface, resulting in shared large-scale topological features between the low- and high-Reynolds-number flows. Although fine-scale vortical structures quickly emerge in the ${\textit{Re}}=$ 10 000 case, the large-scale structures identified by scale decomposition of the turbulent flow resemble those observed at ${\textit{Re}}=600$ . These findings suggest that large-scale vortical features present in laminar extreme aerodynamic flows provide key insights into their higher Reynolds number counterparts, potentially reducing the complexity of flow modelling and control for extreme aerodynamics.