Atomistic modelling of evaporation and explosive boiling of thin film liquid argon over internally recessed nanostructured surface

• Main Authors: Hasan, Mohammad Nasim, Shavik, Sheikh Mohammad, Rabbi, Kazi Fazle, Haque, Mominul
• Format: Conference Proceeding
• Language: English
• Subjects: ARGON; BOILING; Computer simulation; CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; CONFIGURATION; DENSITY; EQUILIBRIUM; EVAPORATION; EXPLOSIVES; Flat surfaces; HEAT; HEAT FLUX; HEAT TRANSFER; Hydrophilic surfaces; Liquid-solid interfaces; LIQUIDS; Molecular dynamics; MOLECULAR DYNAMICS METHOD; Nanostructure; NANOSTRUCTURES; PLATINUM; Recesses; SIMULATION; Solid surfaces; SOLIDS; SURFACES; THIN FILMS; Vapor phases; VAPORS; WETTABILITY; Wetting
• ISSN: 0094-243X; 1551-7616
• DOI: 10.1063/1.4958424

Molecular dynamics (MD) simulations have been carried out to investigate evaporation and explosive boiling phenomena of thin film liquid argon on nanostructured solid surface with emphasis on the effect of solid-liquid interfacial wettability. The nanostructured surface considered herein consists of trapezoidal internal recesses of the solid platinum wall. The wetting conditions of the solid surface were assumed such that it covers both the hydrophilic and hydrophobic conditions and hence effect of interfacial wettability on resulting evaporation and boiling phenomena was the main focus of this study. The initial configuration of the simulation domain comprised of a three phase system (solid platinum, liquid argon and vapor argon) on which equilibrium molecular dynamics (EMD) was performed to reach equilibrium state at 90 K. After equilibrium of the three-phase system was established, the wall was set to different temperatures (130 K and 250 K for the case of evaporation and explosive boiling respectively) to perform non-equilibrium molecular dynamics (NEMD). The variation of temperature and density as well as the variation of system pressure with respect to time were closely monitored for each case. The heat flux normal to the solid surface was also calculated to illustrate the effectiveness of heat transfer for hydrophilic and hydrophobic surfaces in cases of both nanostructured surface and flat surface. The results obtained show that both the wetting condition of the surface and the presence of internal recesses have significant effect on normal evaporation and explosive boiling of the thin liquid film. The heat transfer from solid to liquid in cases of surface with recesses are higher compared to flat surface without recesses. Also the surface with higher wettability (hydrophilic) provides more favorable conditions for boiling than the low-wetting surface (hydrophobic) and therefore, liquid argon responds quickly and shifts from liquid to vapor phase faster in case of hydrophilic surface. The heat transfer rate is also much higher in case of hydrophilic surface.