Strong anisotropy in quasi-static magnetohydrodynamic turbulence for high interaction parameters

TL;DR

This study investigates the anisotropy, energy spectrum, and flux in forced quasi-static magnetohydrodynamic turbulence at high interaction parameters, revealing exponential spectra, inverse energy cascades, and a transition from 2D to 2D-3C flow structures.

Contribution

It provides new insights into the anisotropic behavior and flow dimensionality transitions in high interaction parameter MHD turbulence through forced simulations.

Findings

Energy spectrum becomes exponential at large N.

Inverse energy cascade observed at low wavenumbers.

Flow transitions from 2D to 2D-3C at higher N than previous studies.

Abstract

We simulate forced quasi-static magnetohydrodynamic turbulence and investigate the anisotropy, energy spectrum, and energy flux of the flow, specially for large interaction parameters ($N$). We show that the angular dependence of the energy spectrum is well quantified using Legendre polynomials. For large $N$, the energy spectrum is exponential. Our direct computation of energy flux reveals an inverse cascade of energy at low wavenumbers, similar to that in two-dimensional turbulence. We observe the flow be two-dimensional (2D) for moderate $N$ ($N \sim 20$), and two-dimensional three-component (2D-3C) type for $N \ge 27$. In our forced simulation, the transition from 2D to 2D-3C occurs at higher value of $N$ than Favier et al., ["On the two-dimensionalization of quasistatic magnetohydrodynamic turbulence," Phys. Fluids 22, 075104 (2010)] who employ decaying simulations.