Fast relaxation of a vortex in an exterior field.

par Martin Donati

mardi 16 déc. 2025, 14:00 → 15:00 Europe/Paris

Fokko (ICJ)

In this work with Thierry Gallay, we study the behaviour of a weakly viscous vortex in the 2D incompressible Navier Stokes equations, under  the action of an exterior constraint, such as the presence of other  vortices.  We prove the existence of the phenomenon, observed in  experiments, of fast relaxation towards a "deformed" equilibrium,  namely that lost its initial radial symmetry. This effect is due to  enhanced dissipation caused by the fast rotation of the vortex.