Molecular Dynamics Simulation of Evaporation of a Thin Liquid Argon Layer in a Closed System

Evaporation of a thin liquid film is of significant fundamental importance for both science and engineering applications. This work investigates the evaporation of a thin liquid argon layer into vacuum employing molecular dynamics simulation based on the Lennard-Jones potential. The simulation results demonstrate that the net evaporation rate of an ultra-thin liquid film into vacuum in a closed system may be modeled by the balance of evaporation and condensation based on the Schrage model. The evaporation/condensation coefficient and the non-Maxwellian factor may thus be evaluated. However, the coefficient thus obtained is sensitive to the dimension in the direction normal to the surface. It is also found that the mean temperature for the interface region is 2–3 K lower, while the temperature fluctuations are more violent, than that inside the liquid.