Impact of electrodes positioning on electrothermal convection and heat transfer in a conductive liquid-filled rectangular cavity

This study explores electrothermal convection in a rectangular cavity, where flow is driven by temperature differences caused by internal electrodes. Applying an electric potential across the conductive liquid creates non-uniform internal heat sources through Joule heating, resulting in complex fluid flow and thermal distribution. The investigation focuses on the flow and heat transfer governing dimensionless numbers and the distance between two vertical electrodes influencing convection within the cavity. The finite difference method of order four is utilized to solve the system of partial differential equations, and the numerical findings are validated against existing literature. Results indicate that reduced electrode spacing, and higher Rayleigh numbers significantly enhance local and average Nusselt numbers, promoting heat transfer efficiency, with a notable 60% improvement at the upper wall for De = 1/5 and Ra = 105. Additionally, increased Prandtl numbers lead to a more stable convection but reduced overall heat transfer, highlighting the complex interplay between thermal and flow dynamics. These findings have potential applications in optimizing heat transfer in electrically driven cooling systems, including microelectronic devices, electrochemical systems, and liquid metal cooling for nuclear reactors.