Dependence of nano-confined surface condensation on tangentially external force field

Molecular dynamics (MD) simulations were conducted to investigate the dependence of nano-confined surface condensation on tangentially external force filed. The dynamic behaviors of surface condensation were simulated on a smooth solid surface with fixed wettability (denoted by β) and different external force fields (denoted by f _e ), and on surfaces with different β and fixed f _e . The heat transfer analysis shows that f _e , as a bulk factor, indirectly influences the interfacial thermal resistance (R) by direct influence on surface condensation resulting from the viscous and frictional dissipated heats. This is because the dissipated heats result in superheat of the vapor, leading to the delay or elimination of onset of surface condensation. This finding extends the general understanding that R is only dependent on the interfacial factors, such as β and surface topology. The energy balance analysis shows that, for condensation cases, the largest proportion of the heat transferred through the fluid-solid interface is attributed to the change in the internal energy, while for non-condensation cases, it is attributed to the dissipated heats due to f _e . As f _e increases or β decreases, the dissipated heats increase and gradually take over the total heat transferred from fluid to solid, which finally reduces or suppresses the occurrence of surface condensation.