Noise-generation mechanisms of a wing-tip vortex at moderate angle of attack

An experimental and computational analysis of a wing tip at moderate angle of attack highlights the leading role of the wing-tip vortex wandering along the direction grazing the wing-tip corner in generating far-field noise. The cases of Reynolds numbers $ \textit{Re}_c=0.6\times 10^6$ and $1.0\times 10^6$ at angle of attack $\alpha =10^\circ$ are presented. The vorticity field shows the existence of a system of three wing-tip vortices that co-rotate to form a helical structure. The vortices have wandering motions that develop as they travel downstream. Surface pressure measurements indicate the unsteadiness in the primary vortex to be coherent at a chord-based Strouhal number $ \textit{St}_c\approx 9$ . The…

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  Alliance de recherche numérique du Canada