In many multiscale problems, it is advantageous to model one region using a pore-scale approach and another region using a continuum approach. In this scale, coupling techniques are needed to provide boundary conditions where the two models are joined.

The problem shown here is a low-permeability, continuum-scale gridblock coupled to an adjacent pore-scale model of a packed bed. The three plots below the schematic depict the pressure distribution at the interface for three different realizations of the packed bed structure. The pressure variations are caused by the pore-scale heterogeneity in the packing.