Hydrodynamics of binary-fluid mixtures —An augmented Multiparticle Collison Dynamics approach

The Multiparticle Collision Dynamics technique (MPC) for hydrodynamics simulations is generalized to binary-fluid mixtures and multiphase flows, by coupling the particle-based fluid dynamics to a Ginzburg-Landau free-energy functional for phase-separating binary fluids. To describe fluids with a non-ideal equation of state, an additional density-dependent term is introduced. The new approach is verified by applying it to thermodynamics near the critical demixing point, and interface fluctuations of droplets. The interfacial tension obtained from the analysis of the capillary-wave spectrum agrees well with the results based on the Laplace-Young equation. Phase separation dynamics follows the Lifshitz-Slyozov law.