Estimation of boiling accommodation coefficient from molecular simulation

Despite extensive experimental and numerical investigations over the past century, existing boiling models remain predominantly empirical, limiting their predictive capability and generalizability. As a more fundamental approach, molecular dynamics (MD) simulations have been widely employed to study boiling phenomena, particularly the effects of surface wettability and morphology. However, the accommodation coefficient—a key parameter in macroscopic boiling models—has not yet been evaluated directly from MD simulations. In this work, we employ a piston-based isobaric boiling simulation framework with SPC/E water molecules, implemented using the LAMMPS molecular dynamics solver. The liquid film depletion rate is extracted from the simulation, from which the accommodation coefficient is derived. We investigate its dependence on film thickness to assess wall effects. A novel boundary condition is introduced to impose bulk fluid behaviour at the simulation boundary, enabling evaluation of the accommodation coefficient away from the wall. This boundary force field is derived by integrating the Lennard-Jones force field of water. Furthermore, we explore the influence of surface contamination, specifically sodium dodecyl sulphate (SDS) surfactants, on the boiling process.