The structure of the vortices in freely decaying two-dimensional turbulence
- 25 April 1996
- journal article
- Published by Cambridge University Press (CUP) in Journal of Fluid Mechanics
- Vol. 313, 209-222
- https://doi.org/10.1017/s0022112096002182
Abstract
The structure of a viscous two-dimensional vortex core in a imposed weak strain is analysed, in the same spirit as a similar analysis of strained columnar vortices (Moffatt, Kida & Ohkitani 1994). The analysis is recast in terms of a coordinate deformation, ensuring the uniform validity of the perturbation expansion up to the neighbourhood of a dividing streamline, beyond which it is not expected to work, and from where the exponentially weak vorticity is expected to be stripped to infinity. The orientation and ellipticity of the vorticity distribution of the cores is compared with the results of a numerical experiment in two-dimensional turbulence, and shown to agree. This is interpreted both as a confirmation of the theory and as an indication that the vortices of two-dimensional turbulence are sufficiently long-lived to be controlled by viscous diffusion, even at the relatively large Reynolds numbers of our simulation.Keywords
This publication has 11 references indexed in Scilit:
- Distortion and evolution of a localized vortex in an irrotational flowPhysics of Fluids, 1995
- Stretched vortices – the sinews of turbulence; large-Reynolds-number asymptoticsJournal of Fluid Mechanics, 1994
- Vortex stripping and the generation of high vorticity gradients in two-dimensional flowsFlow, Turbulence and Combustion, 1993
- The elliptical model of two-dimensional vortex dynamics. II: Disturbance equationsPhysics of Fluids A: Fluid Dynamics, 1991
- The elliptical model of two-dimensional vortex dynamics. I: The basic statePhysics of Fluids A: Fluid Dynamics, 1991
- Strained spiral vortex model for turbulent fine structurePhysics of Fluids, 1982
- Motion of an Elliptic Vortex in a Uniform Shear FlowJournal of the Physics Society Japan, 1981
- Structure of a Line Vortex in an Imposed StrainPublished by Springer Science and Business Media LLC ,1971
- Motion and Decay of a Vortex in a Nonuniform StreamPhysics of Fluids, 1965
- On the determination of uniformly accurate solutions of differential equations by the method of perturbation of coordinatesJournal of Applied Mathematics and Mechanics, 1962