Numerical simulation and optimization of natural convection heat transfer enhancement in solar collectors using electrohydrodynamic conduction pump

Abstract

This study investigated the application of electrohydrodynamic conduction pumping for heat transfer enhancement between two 45-degree diagonal plates containing a dielectric fluid, while there is a constant volume heat density inside the inner wall. A numerical simulation was performed to determine the optimum dimensional configuration of electrodes and to clarify how the heat transfer in the fluid between the electrodes is influenced by the electric field magnitude and volume heat density. At low applied voltages, a small flow vortex near the electrodes traps the heat and creates an obstacle blocking the natural convection, which leads to decreasing the efficiency of heat transfer. When the applied voltage is increased to 16kV, the heat trap begins to separate from the wall, which decreases the wall temperature and leads to a faster heat transfer. Therefore, the heat transfer efficiency suddenly increases. In comparison with the case without the electric field, the use of EHD technique can increase the efficiency of heat transfer through the operating fluid almost twice. This configuration of the electrohydrodynamic pump can be used for increasing the efficiency of solar collectors.