Fast relaxation of a viscous vortex in an external flow
Abstract
Abstract We study the evolution of a concentrated vortex advected by a smooth, divergence-free velocity field in two space dimensions. In the idealised situation where the initial vorticity is a Dirac mass, we compute an approximation of the solution which accurately describes, in the regime of high Reynolds numbers, the motion of the vortex centre and the deformation of the streamlines under the shear stress of the external flow. For ill-prepared initial data, corresponding to a sharply peaked Gaussian vortex, we prove relaxation to the previous solution on a time scale that is much shorter than the diffusive time, due to enhanced dissipation inside the vortex core.
Fields of Study & Subjects
Fluid Dynamics and Turbulent Flows
Particle Dynamics in Fluid Flows
Fluid Dynamics and Vibration Analysis
Publication details
- Journal / source
- Nonlinearity
- Volume
- 39
- Issue
- 4
- Pages
- 045006–045006
- Publication date
- 9 April 2026
- Language
- EN