Unsaturated-Saturated Flow in Porous Media Under Centrifugation

Numerical modeling of one dimensional two-phase flow (water/oil) under centrifugation is presented. A new method is analysed to determine capillary-pressure curves (which is an inverse problem). This method is based on modeling the interface between the zone containing only wetting liquid and the zone containing wetting and non wetting liquids. This interface appears when into a fully saturated sample with non-wetting liquid we inject a wetting liquid. The mathematical model of the interface movement (which results in an ODE) is substantial in the construction of an efficient and correct numerical approximation of the original mathematical model for one dimensional two-face flow. The resulting method is a good candidate to be used in the solution of the inverse problem. Both liquids are assumed to be immiscible and incompressible. Some numerical experiments are presented. As a special case, single phase flow (water/air) of a wetting liquid is considered and some numerical experiments concerning inverse problems are presented.