This book provides a user-friendly introduction to convection in porous media, such as fibrous insulation, geological strata, and catalytic reactors. The presentation is self-contained, requiring only routine classical mathematics and the basic elements of fluid mechanics and heat transfer. It will thus be of use not only to researchers and practicing engineers as a review and reference, but also to graduate students and others just entering the field. Applications discussed include such disparate topics as building insulation, energy storage, nuclear-waste disposal, coal and grain storage, chemical reactor engineering, groundwater flow, and stability of snow to avalanches. In this second edition the authors have added: discussions of compact heat exchangers and of tree networks; new material on external natural convection; descriptions of the effects of magnetic fields, of rotations, and of periodic heating; discussions of inclined gradients and of the solidification of alloys; and an extensive treatment of two -phase flows. An extensive list of references (emphasizing recent experimetnal work) provides access to the current research literature.