Effect of temperature and electrode patches on the flow structure and heat transfer of dielectric liquid

Abstract

Electro-thermo-convection (ETC) plays a critical role in heat transfer enhancement, particularly in dielectric fluids subjected to external electric fields. However, the impact of temperature and electrode patch arrangements on the flow structure and heat transfer characteristics of ETC remains underexplored. This study systematically investigates the influence of these factors within a square cavity using the lattice Boltzmann method (LBM). The effects of Rayleigh number (5000 ≤ Ra ≤ 50,000), electric Rayleigh number (100 ≤ T ≤ 200), and patch aspect ratio (0.05 ≤ AR ≤ 0.95) are analyzed. The results show that varying AR significantly alters the flow structure, charge density, and electric potential distribution. Notably, for Ra = 5000 and 10,000, increasing T enhances heat transfer, with the highest average Nusselt number (Nu_avg) observed at AR = 0.05 and T = 200, leading to a 36% and 30% increase, respectively. However, at Ra = 50,000, the effect of T on Nu_avg becomes less pronounced. These findings provide new insights into optimizing ETC for advanced thermal management applications.