ABSTRACT
Fluid Šow in porous media deserves great attention because of its paramount importance both for engineering and for geophysical applications such as „ltration of water, hydrocarbons and gases in the soil. Indeed, the practical interest in convective heat transfer in porous media has greatly increased in the last decades, due to the wide range of applications, such as thermal energy storage, geothermal energy utilisation, petroleum reservoirs, chemical catalytic convectors, storage of grain, pollutant dispersion in aquifers, buried electrical cables, food processing, ceramic radiant porous burners used in industrial plants as ef„cient heat transfer devices, etc. The fundamental nature and the growing volume of work in this area are widely
CONTENTS
4.1 Introduction ................................................................................................ 135 4.2 Description of the Porous Medium ......................................................... 136 4.3 Local Balance Equations in a Porous Medium ...................................... 138
4.3.1 Local Mass Balance ........................................................................ 138 4.3.2 Local Momentum Balance ............................................................ 138 4.3.3 Local Energy Balance .................................................................... 141
4.4 Two-Dimensional Free Convection in a Darcy Medium ..................... 143 4.4.1 Streamfunction Formulation ........................................................ 144 4.4.2 Pressure Formulation .................................................................... 145
4.5 Darcy’s Flow in a Plane Channel ............................................................. 146 4.5.1 Changes due to the Form-Drag Contribution ............................ 147
4.6 Brinkman’s Flow in a Plane Channel...................................................... 148 4.7 Boundary Layer on a Vertical Flat Plate ................................................. 151 4.8 Local Thermal Nonequilibrium .............................................................. 153
4.8.1 Two-Temperature Model by Nield and Bejan ............................ 153 4.8.2 Boundary Conditions for the LTNE Model ............................... 155
4.9 LTNE and Darcy’s Law: The Thermal Entrance Region ...................... 156 References ............................................................................................................. 162
documented in the books by Nield and Bejan (2006), Ingham and Pop (1998, 2002, 2005), Vafai (2005), Pop and Ingham (2001), Bejan et al. (2004), de Lemos (2006), Vadasz (2008) and Kaviany (1995).
