Numerical simulation of unsaturated flow in porous media using the finite volume method

In this paper, the moisture-based form of Richards´ equation that describes the transient flow of water in an unsaturated porous media is investigated numerically for horizontal and vertical infiltration using the cell-centered finite volume method. The fully implicit scheme is selected to represent the time discretization. For horizontal flow, linear and an exponential form are selected to represent the soil water diffusivity. For vertical flow, the Haverkamp functions are used to describe the soil water diffusivity and hydraulic conductivity. Arithmetic mean, harmonic mean and geometric mean are used to estimate the interblock nonlinear soil water diffusivity and hydraulic conductivity. The closer agreement between the predicted water content distributions obtained from; the numerical and Philip´s quasi-analytical solutions indicated that numerical model is a reliable tool for predicting infiltration of water into soil.