Simulating Fluid Wicking into Porous Media with the Lattice Boltzmann Method

Lattice Boltzmann (LB) methods are relatively new, yet simple methods for simulating single and multiphase fluid behavior and are particularly suitable for porous media with irregular geometries. In this chapter, we briefly discuss the fundamentals of the single-phase LB method and its extensions to multiphase fluid systems. In particular, we discuss the merits of an earlier Shan-Chen-type model that was successfully used by us to simulate liquid water retention and wicking in a glass bead system. Although this model can reach excellent results, a ghost phase must be used in this model to generate phase separation. Additional drawbacks are that many simplifying assumptions must be made with regard to the domination of capillary forces over inertial, viscous, and gravitational forces and that the model type does not.