Porous Media

Two classes of model porous media were considered in this paper. Such models have been used as representative of porous media like rocks [3], Portland cement paste constituents [14] and sand [3]. In addition, the classes of porous media studied are bicontinuous media with both the solid phase and the pore phase percolating like real porous media. The first model was an overlapping sphere model consisting of 900 randomly placed digitalized spheres. The spheres were assigned diameters of 13 (System a) and 17 (System b), in units of lattice (or voxel) spacing, resulting in (see Fig. 1) porous media having porosities of 44 percent and 17 percent respectively. The second model was composed of nonoverlapping spheres and had a porosity of about 43 percent with sphere diameter equal to 9 (System c). All porous media formed a 100³ voxel system with periodic boundary conditions.

Figure 1: Digitalized porous medium built from overlapping randomly placed spheres (System a). The light region represents the solid. The porosity is 44 percent. Periodic boundary conditions are employed on all sides.