Computer simulations of domain growth and phase separation in two-dimensional binary immiscible fluids using dissipative particle dynamics.

We investigate the dynamical behavior of binary fluid systems in two dimensions using dissipative particle dynamics. We find that following a symmetric quench the domain size R(t) grows with time t according to two distinct algebraic laws R(t)\ensuremath{\sim}${\mathit{t}}^{\mathit{n}}$: at early times n=1/2, while for later times n=2/3. Following an asymmetric quench we observe only n=1/2, and if momentum conservation is violated we see n=1/3 at early times. Bubble simulations confirm the existence of a finite surface tension and the validity of Laplace's law. Our results are compared with similar simulations which have been performed previously using molecular dynamics, lattice-gas and lattice-Boltzmann automata, and Langevin dynamics. We conclude that dissipative particle dynamics is a promising method for simulating fluid properties in such systems. \textcopyright{} 1996 The American Physical Society.