A Theoretical Investigation Of Natural Convection Heat Transfer From Vertical Isothermal Surfaces And Fins Through Porous Media In Rectangular And Annular Enclosures

Abstract

The phenomenon of natural convection heat transfer in porous media has newlineimportant technological applications in the design of thermal storage systems, newlinethermal insulation of pipes, vessels and buildings, regenerative heat exchangers, etc. newlineInterest in understanding the convective transport process in porous materials is newlineincreasing owing to the development of geothermal technology, high performance newlineinsulation for buildings and for cold storage, renewed interest in the energy efficient newlinedrying processes and many other areas. A few other technological applications of newlinenatural convection in a porous medium are cooling of nuclear fuel in shipping, newlineinsulation of high temperature reactors, burying of drums containing heat newlinegenerating chemicals in the earth, petroleum reservoirs, packed bed columns. newlineExtensive experimental data are available in literature on heat transfer rates newlinein rectangular cavities and on vertical annuli for short as well as long cylinders newlinefilled with saturated porous media. Different solid-fluid combinations have been newlineused in the experimental studies, which form the porous medium. These systems newlineare glass beads-water, steel spheres-heptane, glass-ethylene glycol, polyurethane newlinefoam (PUF)-air, etc. Transformer oil and ethyl alcohol are also among the fluids newlinethat are used. newlineA study of porous media heat transfer in enclosures is important in view of newlineits many practical applications. A thorough understanding of the buoyant flow newlineand heat transfer mechanisms in porous media is possible through accurate newlinetheoretical models. The theoretical model, after its newline