Molecular dynamics simulations of unsteady evaporation of thin liquid argon layer into a vacuum

The unsteady evaporation of liquid argon layer into a vacuum was studied based on molecular dynamics technique using the LAMMPS package. The comparison of the mass flow rate with the known kinetic theory analytical equations was carried out for several temperatures of the liquid layer. It was obtained that after short relaxation time mass flow rate ceases to depend on time for some period. The relaxation time for mass flow rate was estimated. It turned out that this time depends on the temperature of the liquid layer and decreases with increase of its temperature. The mass flow rate values predicted by molecular dynamics simulation are found to be well described by some analytical formulas from kinetic theory. The temporal dynamics of the liquid layer was investigated. The linear dependence between film thinning rate and mass flow rate values was obtained both in the quasi-steady regime and out of it. It was found that liquid interface temperature depends on liquid thickness by power law with an exponent independent of initial liquid film temperature. •The unsteady evaporation of liquid argon layer into a vacuum was studied.•The comparison of the mass flow rate with the kinetic theory equations was made.•The relaxation time for mass flow rate was estimated.•The temporal dynamics of the liquid layer was investigated.