ABSTRACT
The development of new processes or new materials is more and more assisted, besides a classical experimental approach, by the use of theoretical models, able to
Introduction ............................................................................................................ 327 De•nition, Interest, and Objectives of Process Modeling ................................. 327 Modeling of Twin-Screw Extrusion Using a Continuum Mechanics Approach ........................................................................................................... 329
Solid/Melt Transition .................................................................................... 330 Conveying Viscous Fluids ............................................................................ 331 Die Outlet and Liquid/Solid Transition ........................................................ 335
Example of a Global Model: Ludovic© Software .................................................. 337 General Presentation: Data and Organization ................................................... 337 Examples of Global Results .............................................................................. 339
Application to Product Design ............................................................................... 342 Prediction of Starch Transformation ................................................................. 342 Prediction of Cellular Structure and Mechanical Properties ............................. 345
Application to Process Optimization ..................................................................... 347 Optimization of Starch Transformation ............................................................ 347 From Laboratory to Industrial Production: Example of Scale-Up .................... 349
Conclusion and Prospects ...................................................................................... 350 References .............................................................................................................. 351
provide information on the process conditions and their effects on product characteristics. Instead of long and tedious trial and error procedures, process modeling may rapidly help to avoid inappropriate solutions and to concentrate on essential developments. This tendency has largely emerged during the last decades, for example, in the •eld of injection molding of synthetic polymers, where the use of numerical software for calculating mold •lling, residual stresses, or part cooling are now common practices. It has been less common in the food domain, although scienti•c approaches of numerical modeling have been developed in food processing especially by applying computational —uid dynamics (Norton and Sun 2006).
