Isothermal liquid transport in porous media: Capillary hysteresis effects

The isothermal transport of liquids in partially saturated packed beds of glass spheres has been examined. Experimental results and numerical calculations show that in the case of hysteresis-affected capillary pressures a flux equation based on the gradient of the local capillary pressure has to be used. Measured capillary pressures for different transport processes, initial states and liquids are presented. The transport rate is controlled by the effective permeability, which depends on the mobility ratio of gas and liquid flow. At high liquid contents the increasing gas flow resistance causes a decrease of the total transport rate.