Drying of a porous medium with multiple open sides using a pore-network model simulation

Abstract

Pore-network models are employed frequently to study drying in porous media as they, unlike continuum approaches, provide insight into the pore-scale phenomena prevalent during the drying process. Drying characteristics of a 2D rectangular pore network with two opposite sides exposed to the air are investigated numerically, while ignoring gravitational and viscous forces as well as the liquid film effects. The invasion percolation (IP) algorithm is applied to simulate the slow capillary-dominated drying process under isothermal conditions. The drying characteristics of such a network are compared with those of the same network with only one side exposed to the air (the case typically studied in the literature). The results obtained from this novel configuration show that the exposed surface of the network with two open sides dries faster in terms of actual time but requires a larger number of time-steps. Also, the number of thus formed liquid clusters and consequently the number of meniscus pores inside the two-sides-open network is higher than that of the one-side-open network. Therefore, the evaporative mass-loss rate for the network with two open sides is much higher than that of the network with one open side. The study yields some new insights into the evaporation dynamics of networks with multiple open sides.