Effect of nanostructured surface configuration on evaporation and condensation characteristics of thin film liquid argon in a nano-scale confinement

Abstract

Abstract. Molecular dynamics simulation has been carried out to go through the evaporation and condensation characteristics of thin liquid argon film in nanoscale confinement having nanostructured boundary. Nanoscale confinement under consideration consists of hot and cold parallel platinum plates at the bottom and top end of a model cuboid inside which the fluid domain comprised of liquid argon film at the bottom plate and vapor argon in between liquid argon and upper plate of the confinement. Three different confinement configurations have been considered here: (i) Both platinum plates are flat, (ii) Upper plate consisting of transverse slots and (iii) Both plates consisting of transverse slots. The height of the slots is 1.5 nm. Considering hydrophilic nature of top and bottom plates, two different high temperatures of the hot wall was set and an observation was made. For all the structures, equilibrium molecular dynamics (EMD) was performed to reach equilibrium state at 90 K. Then the lower wall is set to two different temperatures like 110 K and 250 K for all three models to perform non-equilibrium molecular dynamics (NEMD). Various system characteristics such as atomic distribution, wall heat flux, evaporative mass flux etc. have been obtained and discussed to have a clear understanding of the effect of nanotextured surface on phase change phenomena.

Dependencies of Surface Condensation on the Wettability and Nanostructure Size Differences

“…They proved that the microevaporation process of the liquid film was consistent with that in the macroprocess. Kuri [ 29 ] simulated evaporation and condensation in a confined nanospace bound by a nanostructure in three different configurations for two different wall superheats, which were set at 110 and 250 K. They compared the heat transportation from the hot wall to the cold wall at these two heating temperatures with three nanostructured surfaces, and they demonstrated that the heat transportation was less in the case of explosive boiling (250 K) compared with normal evaporation (110 K). Liang [ 30 ] verified the Hertz–Knudsen Schrage equation by simulating the evaporation and condensation of liquid argon on the surface of platinum.…”