Homogeneous Vapor Nucleation Using Isothermal Multibody Dissipative Particle Dynamics

TL;DR

This study employs multibody dissipative particle dynamics with a van der Waals equation to simulate homogeneous vapor nucleation, providing new computational visualization and analysis of bubble formation in metastable fluids.

Contribution

First application of multibody dissipative particle dynamics to model homogeneous vapor nucleation with developed visualization tools and thermodynamic interface identification.

Findings

Density varies smoothly from liquid to vapor

Square-gradient term has negligible effect on density variation

Successful visualization of vapor bubble formation

Abstract

Homogeneous nucleation of a vapor bubble from a bulk metastable phase is studied here for the first time using the multibody dissipative particle dynamics model. The van der Waals equation of state is used to define a conservative force that describes the model fluid used in this study. Additional computational tools were developed to help visualize the vapor bubble formed in the system. Continuum thermodynamic ideas are used to help identify the bubble interface and separate particles that constitute the vapor bubble and bulk liquid regions respectively. Using this idea, the density variation is found to vary smoothly from the liquid to vapor regions in the system. The square-gradient term that arises from the free energy expansion of the density is found to have no significant effect on the radial local density variation.