Modelling of Thermo-Electro Hydrodynamic (TEHD) Convection

In Thermo-Electro Hydrodynamics (TEHD), an electric field is applied to a fluid within a heated domain to induce thermal convection. The fluid and the electric field must meet specific conditions to establish a dielectrophoretic force that acts as a buoyancy force on the fluid. This buoyancy force is utilised in experiments to replicate gravitational buoyancy, explore resulting flow structures, or develop heat transfer systems without moving parts. In this study, the electric force field acting on a dielectric fluid in a capacitor is derived from the Maxwell equations and coupled with the Navier-Stokes equation for fluid motion. Furthermore, an Open Source Field Operation and Manipulation (OpenFOAM) solver is extended to incorporate TEHD momentum and energy-contributing terms. In a dimensional analysis, dimensionless parameters are derived and tested. Therefore, parameter studies in 2D approximations of planar and cylindrical geometries are done. Additionally, the 2D investigations are utilised to study the behaviour of heat transfer and boundary layer properties, and some scaling laws are derived. Finally, 3D spherical shell microgravity experiments are analysed and linked to the results of 3D numerical analysis. The results verify the derived methods, which are expanded and applied to the upcoming space experiment, AtmoFlow.