Hybrid lattice Boltzmann model for binary fluid mixtures

Abstract

A hybrid lattice Boltzmann method (LBM) for binary mixtures based on the free-energy approach is proposed. Nonideal terms of the pressure tensor are included as a body force in the LBM kinetic equations, used to simulate the continuity and Navier-Stokes equations. The convection-diffusion equation is studied by finite-difference methods. Differential operators are discretized in order to reduce the magnitude of spurious velocities. The algorithm has been shown to be stable and reproducing the correct equilibrium behavior in simple test configurations and to be Galilean invariant. Spurious velocities can be reduced by approximately an order of magnitude with respect to standard discretization procedure.