Modeling of anisotropic turbulent flows with either magnetic fields or imposed rotation

TL;DR

This paper introduces two innovative models for simulating anisotropic turbulent flows influenced by magnetic fields or rotation, aiming to improve computational efficiency at high Reynolds numbers.

Contribution

It presents two novel turbulence models based on Lagrangian averaging and spectral closures, enhancing simulation accuracy and efficiency for magnetohydrodynamic and rotating flows.

Findings

Models show substantial computational savings.

Validated against high-resolution DNS data.

Applicable to high Reynolds number flows.

Abstract

We present two models for turbulent flows with periodic boundary conditions and with either rotation, or a magnetic field in the magnetohydrodynamics (MHD) limit. One model, based on Lagrangian averaging, can be viewed as an invariant-preserving filter, whereas the other model, based on spectral closures, generalizes the concepts of eddy viscosity and eddy noise. These models, when used separately or in conjunction, may lead to substantial savings for modeling high Reynolds number flows when checked against high resolution direct numerical simulations (DNS), the examples given here being run on grids of up to 1536^3 points.