The geometry of the cooling extruder in a tandem extrusion system is one of the most important factors influencing polymer melt consistency. Understanding momentum and energy transport may help to improve the geometry of a cooling extruder. The objective of this study, was to implement a numerical methodology to model the momentum transport of polymer melt flowing in a cooling extruder.

A numerical technique for solving the momentum equations for non-Newtonian fluid was developed. A finite element algorithm was used to solve the governing equations. A power-law model was used to describe the non-Newtonian behavior of the fluid. The simulation of the polymer melt flow was performed based on a moving barrel formulation. A periodic inlet/outlet boundary condition was used to model fully developed flow. A variety of tests were performed to validate the simulation technique, and the effects of polymer properties on melt flow behavior were studied.