Numerical Investigation of Electrohydrodynamic-Conduction Pumping of Liquid Film in the Presence of Evaporation

Electrohydrodynamic (EHD) conduction pumping is associated with the heterocharge layers of finite thickness in the vicinity of the electrodes, generated by the process of dissociation of the neutral electrolytic species and the recombination of the generated ions. This paper numerically investigates the EHD-conduction pumping of a liquid film in the presence of evaporation. The flow system comprises a liquid film flowing over a two-dimensional flat plate. The vapor phase above the flat plate is extended far beyond the interface. The channel is separated into four different sections: the entrance, electrode, evaporation, and downstream sections. The entrance, electrode, and downstream regions are adiabatic while a constant heat flux is applied in the evaporation section. The concept of EHD-conduction pumping of liquid film in the presence of phase change is numerically demonstrated in this paper. The resultant heat transfer due to conduction pumping is evaluated as well. The results for heat transfer coefficient along the channel indicate considerable improvement of heat transfer coefficient compared with the pressure-driven counterpart.