Nonlinear dynamo in obliquely rotating electroconductive fluids

TL;DR

This paper investigates a new large-scale instability in obliquely rotating electroconductive fluids driven by small-scale forces, leading to nonlinear magneto-vortex dynamo phenomena with localized chaotic structures.

Contribution

It introduces a novel type of instability in obliquely rotating fluids and derives nonlinear equations up to third order, revealing stationary chaotic structures.

Findings

Identification of a new large-scale instability.

Derivation of nonlinear equations for vortex and magnetic perturbations.

Numerical discovery of localized chaotic structures.

Abstract

In the present paper, we study a new type of large-scale instability, which arises in obliquely rotating electroconductive fluids with a small-scale external force of zero helicity. This force excites small-scale velocity oscillations with a small Reynolds number. We used the method of multiscale asymptotic expansions. The nonlinear equations for vortex and magnetic perturbations motions are obtained up to third order in Reynolds number. The linear stage of the magneto-vortex dynamo, arising as a result of instabilities of the type of hydrodynamic and magnetohydrodynamic $\alpha $ - effects, is investigated. Stationary solutions of nonlinear equations of magneto-vortex dynamo in the form of localized chaotic structures are found numerically.