Numerical simulation of electrohydrodynamic effect on natural convection through a vertical enclosure channel

Abstract

ABSTRACTAn externally applied electric field beside a plane layer of dielectric liquid can induce secondary flows. This phenomenon is called electrohydrodynamic (EHD) effect and can result in heat transfer enhancement. In this study the effect of EHD force on natural convection heat transfer coefficient of water through a vertical enclosure channel is investigated by numerical simulation, using Comsol Multiphysics software. Also, the interaction between EHD force, fluid flow field, pressure field and temperature field was investigated by computational fluid dynamics technique. Flow pattern, temperature distribution, back pressure and pressure due to suddenly expanded flow are substantially affected by applied electric field, especially at low Rayleigh numbers. The results show that by increasing the temperature difference up to 40 K and the applied voltage up to 100 V, the heat transfer coefficient is increased by more than 1000 kW/cm2 K for three different enclosure channel lengths. © 2013 Curtin University of Technology and John Wiley & Sons, Ltd.