Visualization of the space-time impulse response of the subcritical wake of a cylinder
The well-known Benard-von Karman cylinder wake is one of the most challenging phenomena of fluid mechanics. As the Reynolds number of the flow around a cylinder passes through a critical value, alternating vortex shedding appears via a Hopf bifurcation. Theoretical studies of the wake have described the appearance of this self-sustained oscillation as the result of a convective to absolute transition resulting in the formation of a global mode. We illustrate here the convective global regime of the subcritical wake by analyzing visualizations of its impulse response.
Le Gal P
Institut de Recherche sur les Phenomenes Hors Equilibre, UM 6594, Universites d'Aix-Marseille I and II-CNRS, 12 Avenue General Leclerc, 13003 Marseille, France.
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