Numerical modeling of materials processing systems

The numerical modeling of the heat transfer and fluid flow processes in manufacturing, particularly in the thermal processing of materials, is discussed in this paper. Three important processes that are considered in detail are polymer extrusion, glass fiber drawing and casting. The governing equations, the relevant boundary conditions and the basic approach to numerically model many of these processes are presented. The importance of material characterization in an accurate mathematical and numerical modeling is brought out, along with the coupling between the process and the resulting properties. The various concerns and computational difficulties that arise due to the non-Newtonian behavior of plastics, exponential temperature dependence of glass viscosity, complex geometry, free surface flow, conjugate transport, material movement, and phase change are considered and some of the important methods to treat these are presented. A few characteristic numerical results are presented on these three important materials processing systems.