| Mixing of polymer components and additives significantly influences the properties of finished products. Such mixing is often performed during processing, especially, with the extrusion process. Single screw extruder mixing sections have all been designed based on trial and error and have never been optimized using numerical techniques. With this project we analyze the flow and mixing in several single screw extruder mixing sections using the boundary element method (BEM). Much insight was gained on the mixing performance of rhomboidal mixing sections. In addition we propose a Monte Carlo integration scheme to model the non-linear behavior of polymer flows. The technique was compared to analytical results, and applied on the simulation of a twisted tape static mixer and a rhomboidal pineapple mixing section. The Monte Carlo integration scheme shows good agreement with analytical solutions when the flow exhibit low changes in strain rate, but it is insufficient to model regions with large variation in strain rates. |
