Effect of electrode arrangement on heat transfer enhancement by electrohydrodynamic conduction pumps in a rectangular channel

Abstract

The present study investigates heat transfer enhancement by electrohydrodynamic (EHD) conduction pumps in a rectangular channel. The effect of electrode arrangement on flow and thermal performance of the rectangular channel by EHD conduction pumps are quantitatively discussed in terms of pressure drop and Nusselt number. The inlet laminar flow with Reynolds number ranging from 100 to 1000. The innovative point of this paper is validating the optimal electrode arrangement over a wider range of Reynolds numbers, the other one is investigating the impact of the number of electrodes on the heat transfer of the EHD conduction pump. The results show that compared to the arrangement of electrode pairs along the same side, electrode pairs arranged on the opposite side have a higher heat transfer capacity due to the stronger vortex strength and lower vortex temperature. For the above two arrangement methods, the heat transfer capacity can be significantly improved when the length of the high-voltage electrode is greater than that of the low-voltage electrode. This result is mainly due to the fact that the electric force enhances the vortex strength, which promotes the perturbation of the thermal boundary layer. The effect of the number of electrode pairs r on the heat transfer capacity is not monotonic. When r < 6, the heat transfer capacity increases with the increase of r due to the generation of more vortices. However, r > 6, as the number of electrode pairs increases, the heat transfer capacity decreases. This result is mainly due to the decrease in the area of the vortex and the increase in the temperature of the vortex.