Intrinsic rotation of toroidally confined magnetohydrodynamics

TL;DR

This study investigates how viscoresistive magnetohydrodynamics in a toroidal setup self-organizes, leading to intrinsic flow rotation that shifts from poloidal to toroidal with increasing Lundquist numbers, influenced by geometric asymmetry.

Contribution

It demonstrates the spontaneous development of toroidal flow in MHD systems and links flow organization to magnetic field alignment and geometric asymmetry.

Findings

Flow transitions from poloidal to toroidal with higher Lundquist numbers

Flow aligns with magnetic fields during self-organization

Up-down asymmetry induces non-zero toroidal angular momentum

Abstract

The spatiotemporal self-organization of viscoresistive magnetohydrodynamics (MHD) in a toroidal geometry is studied. Curl-free toroidal magnetic and electric fields are imposed. It is observed in our simulations that a flow is generated, which evolves from dominantly poloidal to toroidal when the Lundquist numbers are increased. It is shown that this toroidal organization of the flow is consistent with the tendency of the velocity field to align with the magnetic field. Up-down asymmetry of the geometry causes the generation of a non-zero toroidal angular momentum.