Numerical Investigation of Electrohydrodynamic Plumes for Locally Enhanced Cooling in Dielectric Liquids

In this paper, we numerically explored the potential application of electrohydrodynamic (EHD) plumes in cooling local regions with high temperature. The EHD plume is induced by ion injection from a sharp metallic blade immersed in a dielectric liquid. A 2-D simulation which took into account all relevant physical variables for EHD plumes in a nonisothermal liquid was performed. It is found that both the local and average Nusselt numbers dramatically increase with the increase of the electric Rayleigh number (T) and the injection strength parameter (C). However, for the same T and C, the heat transfer augmentation effect is stronger for small Rayleigh numbers (Ra), which can be understood by comparing the relative importance between Coulomb force and buoyancy force.