A lattice-gas model for three immiscible fluids

Abstract

Lattice-gas methods have recently proven very useful for the study of immiscible mixtures of two fluids, with applications ranging from two-phase flow in porous media to spinodal decomposition of binary fluids. Whereas the original one-phase lattice gas models the fluid as a collection of identical particles, in the immiscible two-phase lattice gas the particles are colored red or blue and the collisions between particles are chosen to achieve surface tension. We introduce a new lattice-gas model which extends the two-phase immiscible lattice gas to the simulation of a mixture of three immiscible fluids, i.e., red, green and blue. This extension achieves more than the obvious generalization: immiscible mixtures of three fluids yield phenomena that can be qualitatively different from analogous phenomena observed with two fluids. To demonstrate this point, we show simulations of phase separation of three immiscible fluids and three-phase flow in porous media.