Large scale instabilities in two-dimensional magnetohydrodynamics

Thumbnail Image

Date

Authors

Journal Title

Journal ISSN

Volume Title

Publisher

Abstract

Description

The stability of a sheared magnetic field is analyzed in two-dimensional magnetohydrodynamics with resistive and viscous dissipation. Using a multiple-scale analysis, it is shown that at large enough Reynolds numbers the basic state describing a motionless fluid and a layered magnetic field, becomes unstable with respect to large scale perturbations. The exact expressions for eddy-viscosity and eddy-resistivity are derived in the nearby of the critical point where the instability sets in. In this marginally unstable case the nonlinear phase of perturbation growth obeys to a Cahn-Hilliard-like dynamics characterized by coalescence of magnetic islands leading to a final new equilibrium state. High resolution numerical simulations confirm quantitatively the predictions of multiscale analysis.
6 pages RevTeX, 6 PostScript figures

Keywords

Chaotic Dynamics

Citation

URI

http://salesiana.dossiersoluciones.com/handle/123456789/15651

Consulte el texto completo en el siguiente enlace:

https://arxiv.org/abs/chao-dyn/9810026
 http://arxiv.org/abs/chao-dyn/9810026

Collections

arXiv