| This Thesis is concerned with the analytical and numerical modeling of capillary and gravity induced viscous film flow during the isothermal drying of a porous medium using pore-network simulation techniques. The objective is to simulate the evaporation of a liquid from an initially saturated porous medium in the presence of gravity force. The phenomena taken into account are the gravity and capillary forces on the viscous flow of wetting liquid film along the corners of capillary tubes, the capillary effects at the gas-liquid menisci by means of the invasion percolation rules and the diffusive transport in the gas phase. The problem is characterized by two dimensionless parameters, diffusion based capillary number, Caf and a gravity based Bond number, Bg. An extensive study of the effects of gravity on growth of the film region and the effects on the drying rates is carried out. |
