PROBLEMS OF MODELING FLOW AND HEAT TRANSFER IN POROUS MEDIA

The paper presents an up-to-date overview of the theoretical and the engineering application aspects of the porous media. Problems which arise in modeling the flow and heat transfer phenomena by momentum and energy equations, and which are not present in the corresponding free-fluid flow, are discussed in more detail. Such problems arise from the higher order terms in the momentum equation and from thermal dispersion or local thermal equilibrium in the energy equation. The general class of boundary conditions which differentiate the flow phenomena from that of corresponding free-fluid flow have also been discussed in more detail. The channeling phenomena caused by the nonhomogeneity of porosity near the wall is presented and models which approximate the porosity variation are demonstrated. The boundary effects and their influence on the porous media have also been analyzed. The important aspects of engineering applications of the porous media and other applications of the macroscopic approach typical for porous media were also discussed. Finally conclusions corresponding to problems met in the modeling of flow and heat transfer in porous media are drawn.