Rapid generation of angular momentum in bounded magnetized plasma

TL;DR

This paper uses direct numerical simulations to study how angular momentum is rapidly generated in bounded magnetized plasma, highlighting the role of magnetic fluctuations and geometry.

Contribution

It introduces new insights into angular momentum generation mechanisms in bounded MHD turbulence, emphasizing the impact of magnetic fluctuations and geometry.

Findings

Angular momentum is rapidly generated in nonaxisymmetric geometries.

Magnetic fluctuations significantly enhance angular momentum generation.

A magnetic angular momentum or angular field develops over longer timescales.

Abstract

Direct numerical simulations of two-dimensional decaying MHD turbulence in bounded domains show the rapid generation of angular momentum in nonaxisymmetric geometries. It is found that magnetic fluctuations enhance this mechanism. On a larger time scale, the generation of a magnetic angular momentum, or angular field, is observed. For axisymmetric geometries, the generation of angular momentum is absent; nevertheless, a weak magnetic field can be observed. The derived evolution equations for both the angular momentum and angular field yield possible explanations for the observed behavior.