Numerical modelling of multiphase flow and transport phenomena in screw extruders

Many plastic products are processed in extruders. These devices exhibit complex flow phenomena, especially when multiple phases are present, as seen in processes such as grafting and foaming. In his thesis, Tim Kousemaker introduces comprehensive, multiphysics computational fluid dynamics models of multiphase flow in extruders. The couplings between mass transfer, heat transfer, shear and concentration dependent viscosity and chemical reactions are accounted for - together with various multiphase flow models - to model the complex flows present in extruders. Results show that this multiphysics approach is necessary to predict complex phenomena such as e.g., backflow, plasticization and sputtering at the die. Additionally, Kousemaker shows that linear and static models may lead to erroneous conclusions and incorrect policy insights.

Dissertation: https://hdl.handle.net/11370/1617fca0-5478-497c-b45c-957bd6a33d06