Recent advances in pore-scale models for drying of porous media

This paper presents a review of the recent advances in pore-scale modelling of drying in capillary porous media. The development of pore network models in drying has been first motivated by several fundamental features of drying that cannot be fully explained within the framework of continuum models. These features include the dry patch phenomenon and the constant drying rate period. A second source of motivation has been the advances made in pore-scale modelling of immiscible displacements in porous media and the increasing conviction that concepts developed in this area could be utilised to model drying. These concepts are recalled. We describe how they have been used for developing a pore network model of drying driven by mass transfer. A review of the main results is made, including pattern formation, drying rates and some recent results regarding drying of a porous medium containing a binary mixture and the influence of heat transfer. The use of network models for computing effective transport properties is discussed. Open problems are discussed. (C) 2002 Elsevier Science B.V. All rights reserved.