INTRODUCTION
1.1 GENERAL
The transport, reaction, and phase change of fluid in natural
and engineered porous media rely on the knowledge gained in studying these
phenomena in otherwise plain media. The presence of permeable solid (which is
assumed to be rigid and stationary) influences these phenomena significantly. So
fluid flow and heat transfer in porous media have become a separate topic for
research in the past forty years in view of their importance in various applications