The The book book was was planned planned in in such such a a manner manner that that two two basic basic goals goals would would be be reached. reached. On On the the one one hand, hand, the the goal goal was was to to show show some some new new results results in in the the field field of of modeling modeling transport transport through through highly highly heterogeneous heterogeneous media, media, based based on on the the homogenization homogenization theory. theory. Multiple Multiple new new mathematical mathematical models models of of transport transport are are presented presented herein, herein, studying studying their their properties, properties, developing developing methods methods to to compute compute effective effective parameters parameters of of the the averaged averaged media, media, simulation simulation of of cell cell problems, problems, using using new new models models to to simulate simulate some some practical practical problems. problems. High High heterogeneity heterogeneity being being subjected subjected to to the the homogenization homogenization procedure, procedure, generates generates non-local non-local phenomena phenomena and and then then gives gives a a possibility possibility to to develop develop a a new, new, non-local non-local (or (or "dynamic"), "dynamic"), theory theory of of transport transport in in porous porous media. media.

Capillary phenomena occur in both natural and human-made systems, from equilibria in the presence of solids (grains, walls, metal wires) to multiphase flows in heterogeneous and fractured porous media. This book, composed of two volumes, develops fluid mechanics approaches for two immiscible fluids (water/air or water/oil) in the presence of solids (tubes, joints, grains, porous media). Their hydrodynamics are typically dominated by capillarity and viscous dissipation. This first volume presents the basic concepts and investigates two-phase equilibria, before analyzing two-phase hydrodynamics in discrete and/or statistical systems (tubular pores, planar joints). It then studies flows in heterogeneous and stratified porous media, such as soils and rocks, based on Darcy’s law. This analysis includes unsaturated flow (Richards equation) and two-phase flow (Muskat equations). Overall, the two volumes contain basic physical concepts, theoretical analyses, field investigations and statistical and numerical approaches to capillary-driven equilibria and flows in heterogeneous systems

The main aim of this paper is to present some new and general results, ap plicable to the the equations of two phase flow, as formulated in geothermal reservoir engineering. Two phase regions are important in many geothermal reservoirs, especially at depths of order several hundred metres, where ris ing, essentially isothermal single phase liquid first begins to boil. The fluid then continues to rise, with its temperature and pressure closely following the saturation (boiling) curve appropriate to the fluid composition. Perhaps the two most interesting theoretical aspects of the (idealised) two phase flow equations in geothermal reservoir engineering are that firstly, only one component (water) is involved; and secondly, that the densities of the two phases are so different. This has led to the approximation of ignoring capillary pressure. The main aim of this paper is to analyse some of the consequences of this assumption, especially in relation to saturation changes within a uniform porous medium. A general analytic treatment of three dimensional flow is considered. Pre viously, three dimensional modelling in geothermal reservoirs have relied on numerical simulators. In contrast, most of the past analytic work has been restricted to one dimensional examples.

The vadose zone is the region between ground level and the upper limits of soil fully saturated with water. Hydrology in the zone is complex: nonlinear physical, chemical, and biological interactions all affect the transfer of heat, mass, and momentum between the atmosphere and the water table. This book takes an interdisciplinary approach to vadose zone hydrology, bringing together insights from soil science, hydrology, biology, chemistry, physics, and instrumentation design. The chapters present state-of-the-art research, focusing on new frontiers in theory, experiment, and management of soils. The collection addresses the full range of processes, from the pore-scale to field and landscape scales.

Although the empirical treatment of fluid flow and heat transfer in porous media is over a century old, only in the last three decades has the transport in these heterogeneous systems been addressed in detail. So far, single-phase flows in porous media have been treated or at least formulated satisfactorily, while the subject of two-phase flow and the related heat-transfer in porous media is still in its infancy. This book identifies the principles of transport in porous media and compares the avalaible predictions based on theoretical treatments of various transport mechanisms with the existing experimental results. The theoretical treatment is based on the volume-averaging of the momentum and energy equations with the closure conditions necessary for obtaining solutions. While emphasizing a basic understanding of heat transfer in porous media, this book does not ignore the need for predictive tools; whenever a rigorous theoretical treatment of a phenomena is not avaliable, semi-empirical and empirical treatments are given.