Electrically driven liquid and liquid film flow in large and small scales in the presence and absence of phase change

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 recombination of the generated ions. This theoretical and numerical study provides a fundamental understanding of electrically driven liquid flow based on conduction phenomenon in macro-, micro- and nano-scales. The role of EHD conduction mechanism is also studied for heat transfer enhancement in numerous applications which involve both single phase and stratified two phase models with phase change.;In the fundamental part of this study, a numerical model is developed to study electrically driven liquid and liquid film flow. The results are validated against available experimental measurements of EHD conduction pumping of isothermal liquid film under various operating conditions. The numerical model is further expanded to include the phase change process due to the liquid evaporation or condensation.;A matched asymptotic analysis is conducted to study the interaction of the electric double layer and heterocharge layer in macro-scales. In addition, the effect of electrokinetically induced double layer due to the presence of surface zeta potential and the coupling of such layer with the dissociation-induced heterocharge layer is studied to explore the impact of this coupling on the flow structure and volumetric flow rate in micro- and nano-scales. Finally, a linear stability analysis is conducted for a parallel flow subject to bipolar charge dissociation with additional focus on its heat transfer characteristics. It is observed that charge dissociation at sufficiently high levels promotes instabilities in a Poiseuille flow.;The application segment of this study concentrates on the innovative active heat transfer enhancement techniques using EHD conduction phenomenon in macro- and micro-scales in terrestrial and micro-gravity environments. The applications range from utilizing EHD as the sole pumping and augmentation mechanism to adopting EHD conduction as an auxiliary tool superposed onto an externally driven fluid flow to enhance the heat transfer capacity of the system. In addition, EHD conduction mechanism is utilized as an effective tool to generate circulation flow inside reservoirs to effectively mix and thermally homogenize the liquid.