The dynamics of capillary rise in a porous medium have been mostly studied in initially dry systems. As initial saturation and initial hydraulic conditions in many natural and industrial porous media can be variable, it is important to investigate the influence of initial conditions on the dynamics of the process. In this study, using dynamic pore-network modeling, we simulated capillary rise in a porous medium for different initial saturations (and consequently initial capillary pressures). Furthermore, the effect of hydraulic connectivity of the wetting phase in corners on the height and velocity of the wetting front was studied. Our simulation results show that there is a trade-off between capillary forces and trapping due to snap-off, which leads to a nonlinear dependence of wetting front velocity on initial saturation at the pore scale. This analysis may provide a possible answer to the experimental observations in the literature showing a non-monotonic dependency between initial saturation and the macroscopic front velocity. © Soil Science Society of America.
|Original language||English (US)|
|Journal||Vadose Zone Journal|
|State||Published - Sep 7 2012|
Bibliographical noteKAUST Repository Item: Exported on 2020-10-01
Acknowledged KAUST grant number(s): KUK-C1-017-12
Acknowledgements: This research was funded by a King Abdullah University of Science and Technology (KAUST) Center-in-Development Grant awarded to Utrecht University (Grant no. KUK-C1-017-12). We would like to acknowledge the reviewers of this paper, especially Max Kohne of UFZ, Leipzig, for thoughtful comments and valuable suggestions that helped to improve the manuscript.
This publication acknowledges KAUST support, but has no KAUST affiliated authors.