Experimental characterization of the 3D dynamics of a laminar shallow vortex dipole

Laurent Lacaze (1) , Pierre Brancher (1) , Olivier Eiff (1) , Ludovic Labat (1)

1 IMFT - Institut de mécanique des fluides de Toulouse

Experimental results on the dynamics of a vortex dipole evolving in a shallow fluid layer are presented. In particular, the generation of a spanwise vortex at the front of the dipole is observed in agreement with previous experiments at larger Reynolds numbers. The results show that this secondary vortex is of comparable strength to the dipole. The present physical analysis suggests that the origin of this structure involves the stretching induced by the dipole of the boundary-layer vorticity generated by the dipole's advection over the no-slip bottom.

Mots clés: Vortex dynamics; Shallow water

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

Laurent Lacaze, Pierre Brancher, Olivier Eiff, Ludovic Labat. Experimental characterization of the 3D dynamics of a laminar shallow vortex dipole. Experiments in Fluids, 2010, 48 (2), pp.225-231. ⟨10.1007/s00348-009-0732-4⟩. ⟨hal-01727774⟩