The decay of magnetohydrodynamic turbulence in a confined domain

TL;DR

This paper investigates how non-periodic boundary conditions in a confined circular domain influence the decay and behavior of two-dimensional magnetohydrodynamic turbulence, revealing persistent flow regimes and boundary effects on energy decay.

Contribution

It extends understanding of MHD turbulence decay by analyzing non-periodic boundary effects and identifying persistent flow regimes in confined geometries.

Findings

Flow regimes similar to periodic domains are observed in confined settings.

Solid boundaries affect energy decay and field alignment.

Final states show specific relationships between velocity and magnetic fields.

Abstract

The effect of non periodic boundary conditions on decaying two-dimensional magnetohydrodynamic turbulence is investigated. We consider a circular domain with no-slip boundary conditions for the velocity and where the normal component of the magnetic field vanishes at the wall. Different flow regimes are obtained by starting from random initial velocity and magnetic fields with varying integral quantities. These regimes, equivalent to the ones observed by Ting, Matthaeus and Montgomery [Phys. Fluids {\bf 29}, 3261, (1986)] in periodic domains, are found to subsist in confined domains. We examine the effect of solid boundaries on the energy decay and alignment properties. The final states are characterized by functional relationships between velocity and magnetic field.