Analytical characterization and conceptual assessment of solid and fluid temperature differentials in porous media

An analytical characterization of forced convective flow through a channel filled with a porous medium is presented in this work. Based on a two-equat ion model, including transverse conduction contributions, exact solutions a re obtained for both fluid and solid phase temperature fields. The Nusselt number is also obtained in terms of the pertinent physical parameters, name ly the Blot number for the internal heat exchange and the ratio of effectiv e conductivities between the fluid and solid phases. It is shown that the h eat transfer characteristics can be classified within three regimes, each o f which is dominated by one of three distinctive heat transfer mechanisms, i.e., fluid conduction; solid conduction and internal heal exchange between solid and fluid phases. Based on these results, a complete electrical ther mal network representative of transport through porous media is established . In addition, an analytical characterization and conceptual assessment of solid and fluid temperature differentials is presented. the validity of the one-equation model is investigated and a practical criterion is suggested for channels with different cross sections. (C) 1998 Elsevier Science Ltd. All rights reserved.