Energy pathways in large- and small-scale convection-driven dynamos

TL;DR

This paper explores how energy transfers between velocity and magnetic fields in convection-driven dynamos, revealing different mechanisms for large- and small-scale magnetic field generation through numerical simulations.

Contribution

It provides a detailed energy pathway analysis distinguishing large- and small-scale dynamo mechanisms based on direct numerical simulations.

Findings

Distinct energy transfer mechanisms identified for large- and small-scale dynamos

Boundary conditions influence the magnetic field generation process

Energy balance analysis clarifies the roles of mean and turbulent components

Abstract

We investigate the energy pathways between the velocity and the magnetic fields in a rotating plane layer dynamo driven by Rayleigh-B\'enard convection using direct numerical simulations. The kinetic and magnetic energies are divided into mean and turbulent components to study the production, transport, and dissipation associated with large and small-scale dynamos. This energy balance-based characterization reveals distinct mechanisms for large- and small-scale magnetic field generation in dynamos, depending on the nature of the velocity field and the conditions imposed at the boundaries.