Microfluidics of imbibition in random porous media.

A free-energy lattice Boltzmann approach has been used to perform simulations of liquid penetration into random porous media. We focus our study on the effects of microstructures, particularly microtopography, on liquid penetration driven by capillary force and external pressure. For this purpose we set up a model structure that consists of a network of interconnected capillaries with varying pore geometries. The results showed that the discontinuities in the solid-surface curvature, as are present as corners on the capillary surfaces, have strong influences on liquid penetration through their pinning effects and interactions with local geometry.