Equilibration of van der waals liquid drop with vapour in smoothed particle hydrodynamics

We present a liquid-vapour equilibrium using Smoothed Particle Hydrodynamics (SPH), considering the van der Waals equation of state. A hyperbolic kernel function and variable smoothing length are considered along with the periodic boundary condition to study liquid drop-vapour coexistence for different vapour systems. The effect of the existence of the vapour on the coefficient of surface tension is studied, and noted that the surface tension decreases with increase of the density of vapour surrounding it.