Direct forcing immersed boundary method for electro-thermo-buoyant flows in enclosures

This study investigates electro-hydrodynamic (EHD) and electro-thermo-hydrodynamic (ETHD) phenomena in dielectric liquids, and focusses on charge injection as a source of unipolar charges. The studied configuration consists of a hot spherical electrode placed in the center of a cold cubic enclosure, and is numerically simulated using the direct forcing immersed boundary (IB) method. Flow characteristics for both EHD and ETHD flows within this configuration are thoroughly analyzed, both quantitatively and qualitatively, across a representative range of operating parameters. Analyzing ETHD flows results in a more than threefold increase in heat flux from the hot embedded electrode compared to natural convection alone. This study highlights both the similarities and the differences in flow and heat transfer characteristics between the realistic 3D configuration and its 2D counterpart, paving the way for further application of the direct forcing IB method in the analysis of EHD and ETHD flows typical of realistic configurations.