In a wide variety of manufacturing processes, heat transfer and fluid flow considerations play a very important role. These include processes such as casting, crystal growing, hot rolling, optical fiber drawing, solder­ ing, welding, gas cutting, plastic injection molding and extrusion, metal forming, and heat treatment. Table 7.1 presents different types of materials processing operations along with a few important examples. Such manufac-

turing processes, in which the heat transfer and fluid flow aspects are of crucial importance in determining the properties of the final product, are also often categorized as thermal-based manufacturing or materials pro­ cessing. A few typical thermal manufacturing processes are sketched in Fig. 7.1, including optical glass fiber drawing, continuous casting, mold casting, and plastic screw extrusion. A fairly wide range of important manufacturing techniques involve thermal processing of materials. Consequently, a tremen­ dous research effort has been directed at the thermal transport that is of interest in such processes.