A practical model of convective dynamics for stellar evolution calculations

TL;DR

This paper develops a practical turbulent closure model for stellar convection, capturing the transition from radiative to turbulent heat transport, including effects of rotation, shear, and magnetic fields, validated against experimental data.

Contribution

It extends existing closure models to include heat transport and compares them with experimental results, aiding multi-dimensional stellar evolution calculations.

Findings

Successfully models the transition from radiative to turbulent convection.

Extends Ogilvie's closure model to include heat transport.

Aligns model predictions with Rayleigh-Benard convection experiments.

Abstract

Turbulent motions in the interior of a star play an important role in its evolution, since they transport chemical species, thermal energy and angular momentum. Our overall goal is to construct a practical turbulent closure model for convective transport that can be used in a multi-dimensional stellar evolution calculation including the effects of rotation, shear and magnetic fields. Here, we focus on the first step of this task: capturing the well-known transition from radiative heat transport to turbulent convection with and without rotation, as well as the asymptotic relationship between turbulent and radiative transport in the limit of large Rayleigh number. We extend the closure model developed by Ogilvie (2003) and Garaud and Ogilvie (2005) to include heat transport and compare it with experimental results of Rayleigh-Benard convection.