Self-adaptation and viscous selection in concentrated two-dimensional vortex dipoles

D. Sipp (1) , L. Jacquin (1) , Carlo Cosssu (1, 2)

1 ONERA - The French Aerospace Lab [Meudon]
2 LadHyX - Laboratoire d'hydrodynamique

In this Letter we deal with 2D direct numerical simulations of concentrated vortex dipoles. We show that various initial dipolar vorticity distributions evolve towards a specific family of dipoles parametrized by the dipole aspect ratio a/b, where a is the radius of the vortices based on the vorticity polar moment in half a plane and b is the separation between the vortex centroids. This convergence is achieved through viscous effects. The considered Reynolds numbers Re= G/v are Re= 3000 and Re= 15000. Moreover, all the dipoles of this family are quasi-steady solutions of the Euler equations. Their scatter plots and drift velocities are given for a/b<03. © 2000 American Institute of Physics.

Domains: Physics [physics]; Mechanics [physics]; Fluid mechanics [physics.class-ph]; Engineering Sciences [physics]; Mechanics [physics.med-ph]; Fluids mechanics [physics.class-ph]

D. Sipp, L. Jacquin, Carlo Cosssu. Self-adaptation and viscous selection in concentrated two-dimensional vortex dipoles. Physics of Fluids, 2000, 12 (2), pp.245-248. ⟨10.1063/1.870325⟩. ⟨hal-01025367⟩