Modeling compressed turbulent plasma with rapid viscosity variations

TL;DR

This paper introduces two-equation models to simulate turbulent plasma behavior during compression, effectively capturing rapid viscosity changes, relaminarization, and self-similar regimes through data-driven closures.

Contribution

The work develops novel two-equation models with data-driven closures to accurately represent turbulent plasma dynamics with viscosity variations.

Findings

Model captures relaminarization phases.

Successfully mimics self-similar regimes.

Recovers rapid transition limits.

Abstract

We propose two-equations models in order to capture the dynamics of a turbulent plasma undergoing compression and experiencing large viscosity variations. The models account for possible relaminarization phases and rapid viscosity changes through closures dependent on the turbulent Reynolds and on the viscosity Froude numbers. These closures are determined from a data-driven approach using eddy-damped quasi normal markovian simulations. The best model is able to mimic the various self-similar regimes identified in \citet{Viciconte2018} and to recover the rapid transition limits identified by \citet{Coleman1991}.