Insights from inside the spinodal : Bridging thermalization time scales with smoothed particle hydrodynamics

Abstract

The dynamics of separated phases below the spinodal curve are strongly affected by the strength of coupling to an external heat bath. The authors investigate the processes of separation and domain growth of completely unstable liquid-vapor systems by modifying the computer simulation method smoothed particle hydrodynamics. When a liquid is quenched to a completely unstable state, the separation instantaneously occurs throughout the whole volume, which is called spinodal decomposition. Theoretical descriptions of the phenomenon mostly approximate isothermal behavior, although the temperature is one of the most important factors in correctly describing these phase transitions, since latent heat can be released. The authors go a step further by considering the coupling to a heat bath, such that reaching the desired final temperature depends on the strength of coupling. The, herein used, simulation method allows to follow the temporal evolution of the separated phases inside the unstable region and gives insights to the understanding of diffuse interface formation and domain growth stagnation.