Modelling Thermo-Electrohydrodynamic Convection in Rotating Spherical Shell Using OpenFOAM®

Abstract

Convection in rotating spherical shells can be considered a simplified analogue of many geophysical and astrophysical flows. Here, we investigate a direct numerical simulation of a dielectric fluid in an electric central force field inducing thermo-electrohydrodynamic (TEHD) convection with numerical methods to obtain an accurate solution of the transport equations describing rotating TEHD convection in a non-isothermally heated spherical shell. The choice of the numerical model is based on the International Space Station Experiment GeoFlow and its successor, AtmoFlow. The numerical methods consist of a custom-developed finite volume solver based on the OpenFOAM ecosystem that is not limited to any geometric restrictions, a commercially developed finite element method, and a pseudo-spectral method. This study aims to validate a custom-coded finite volume solver for investigating TEHD convection for a parametric study of the AtmoFlow spherical shell experiment. The developed TEHD finite volume solver showed solution errors of 1% or less compared to the other two implemented numerical methods.