SIMULATION OF INTENSITY OF SEGREGATION DISTRIBUTIONS USING 3-DIMENSIONAL FEM ANALYSIS - APPLICATION TO COROTATING TWIN-SCREW EXTRUSION PROCESSING

The corotating twin screw extrusion flow is simulated to generate the distributions of intensity of segregation and integral measures of mixing and forwarding. The simulation focused on the lenticular kneading disk elements that necessitated the application of a three-dimensional finite element method to solve the conservation equations. The intensity of segregation distributions were determined by introducing a tracer blob numerically and tracking the concentration of the tracer particles as a function of location and time. In spite of the chaotic nature of the dynamics of this flow, the analyses provided the broad features of twin extrusion flow and its ability to mix. The processing characteristics of kneading disks were found to depend on the stagger angle and complemented earlier numerical and experimental results on residence time distributions and color incorporated tracer analyses. (C) 1995 John Wiley & Sons, Inc.