Leading-edge vortex shedding from rotating wings

TL;DR

This study numerically investigates the behavior of leading-edge vortices on rotating triangular wings at low Reynolds number, analyzing vortex stability, shedding, and spanwise flow mechanisms through simulations and models.

Contribution

It introduces a detailed numerical analysis of vortex shedding and spanwise flow on rotating wings, including an inviscid model for flow outside the recirculation bubble.

Findings

Transition from vortex attachment to shedding depends on aspect ratio and angle of attack.

Spanwise flow in the recirculation bubble is driven by centrifugal force, viscosity, and incompressibility.

An inviscid model explains the flow outside the bubble.

Abstract

The paper presents a numerical investigation of the leading-edge vortices generated by rotating triangular wings at Reynolds number $Re=250$. A series of three-dimensional numerical simulations have been carried out using a Fourier pseudo-spectral method with volume penalization. The transition from stable attachment of the leading-edge vortex to periodic vortex shedding is explored, as a function of the wing aspect ratio and the angle of attack. It is found that, in a stable configuration, the spanwise flow in the recirculation bubble past the wing is due to the centrifugal force, incompressibility and viscous stresses. For the flow outside of the bubble, an inviscid model of spanwise flow is presented.