Heat transfer is associated with the process of transmission of energy from one region to another as a result of temperature difference between them.The process of free convection as a mode of heat transfer has wide applications in the fields of Chemical Engineering, Aeronautical and Nuclear power generation. Radiative flow plays a vital role in many industrial and environmental process, example, heating and cooling chambers, fossil fuel combustion energy process, evaporation from large open water reservoirs, astro physical flows and solar power technology etc. Heat transfer in porous thermal insulation within vertical cylindrical annular enable engineers to use insulation more effectively. In view of these applications this book is useful for engineers of different fields,researchers etc.