Vortical similarities across laminar and turbulent extreme gust encounters

TL;DR

This paper reveals that large-scale vortical structures in laminar and turbulent extreme gust encounters are remarkably similar, offering insights that could simplify flow modeling and control across different Reynolds numbers.

Contribution

It uncovers the similarity of large-scale vortical structures in laminar and turbulent flows during extreme gust encounters, linking low and high Reynolds number flow behaviors.

Findings

Large-scale vortical structures are similar at Re = 600 and 10,000.

Gust-induced vorticity flux at the wing surface drives vortex formation.

Large-scale features in turbulent flows resemble those in laminar flows.

Abstract

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 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 Re = 10,000 case, the large-scale structures identified by scale decomposition of the turbulent flow resemble those observed at 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 modeling and control for extreme aerodynamics.