Numerical Simulation of Viscous Flow in a Partially filled Co-rotating Twin Screw Extruder

Abstract

Abstract The free-surface flow of fully melted material in the conveying section of a co-rotating twin screw extruder has been simulated numerically with the Finite Volume Method and an Eulerian multiphase model. In this model the interface is captured in an implicit manner with the help of the local volume fraction in a cell. The results presented here reveal the power and conveying characteristics of the twin screw configuration. Some interesting findings are discussed for the power characteristic in the fully filled state as well. The flow field and derived quantities are discussed with regards to the axial transport, symmetries in the flow field and locations of high energy dissipation. All results are compared to the fully filled state. Additionally, a new term, the volume flux based “conveying degree”, is introduced in this paper. The difference to the volume-based degree of fill is pointed out.