The rapid growth of literature on convective heat and mass transfer through porous media has brought both engineering and fundamental knowledge to a new state of completeness and depth. Additionally, several new questions of fundamental merit have arisen in several areas which bear direct relation to further advancement of basic knowledge and applications in this field. For example, the growth of fundamental heat transfer data and correlations for engineering use for saturated media has now reached the point where the relations for heat transfer coefficients and flow parameters are known well enough for design purposes. Multiple flow field regimes in natural convection have been identified in several important enclosure geometries. New questions have arisen on the nature of equations being used in theoretical studies, i. e. , the Validity of Darcy assumption is being brought into question; Wall effects in high and low velocity flow fields have been found to play a role in predicting transport coefficients; The formulation of transport problems in fractured media are being investigated as both an extension of those in a homogeneous medium and for application in engineering systems in geologic media and problems on saturated media are being addressed to determine their proper formulation and solution. The long standing problem of how to adequately formulate and solve problems of multi-phase heat and mass transfer in heterogeneous media is important in the technologies of chemical reactor engineering and enhanced oil recovery.
