Bifurcations and symmetry breaking in the wake of axisymmetric bodies

David Fabre (1) , Franck Auguste (1) , Jacques Magnaudet (1)

1 IMFT - Institut de mécanique des fluides de Toulouse

We consider the generic problem of wake instabilities past fixed axisymmetric bodies, and focus on the extreme cases of a sphere and a flat disk. Numerical results reveal that the wakes of these two bodies evolve differently as the Reynolds number is increased. Especially, two new vortex shedding modes are identified behind a disk. To interpret these results, we introduce a model based on the theory of mode interactions in presence of O(2) symmetry. This model, which was initially developed for the Taylor-Couette system, allows us to explain the structural differences observed in the evolution of the two types of wakes and to accurately predict the evolution of the lift force.

Mots clés: Revolving body; Wakes; Symmetry breaking; Bifurcation; Laminar flow; Hydrodynamic instability

Domaines: Mécanique des fluides [physics.class-ph]; Mécanique des fluides [physics.class-ph]

David Fabre, Franck Auguste, Jacques Magnaudet. Bifurcations and symmetry breaking in the wake of axisymmetric bodies. Physics of Fluids, 2008, vol. 20, pp. 1-4. ⟨10.1063/1.2909609⟩. ⟨hal-00874366⟩