Numerical and analytical investigation of viscous fluids in a screw extruder

This study presents a flow model for a single screw extruder which has been investigated by means of analytical and numerical methods. Flow phenomena in single screw extruders has evoked attention of many researchers since non-Newtonian type of fluid transport by an extruder is utilized in many industrial applications. In this study we focused on the Newtonian-type of fluid transport by a single screw extruder since we aimed to generate an analytical model for the simplified Navier-Stokes equations under certain boundary conditions. The analytical model for a steady, laminar, isothermal and incompressible flow is derived using integral transform technique for a highly viscous flow where the convective acceleration terms are assumed to be negligible. Numerical investigation is conducted by an incompressible, laminar, finite volume based flow solver using a Volume of Fluid (VoF) approximation. An appropriate single-screw extruder model is used for the simulations. The novelty of the study relies on the usage of a simplified analytical model for a highly viscous flow and the comparison between the analytical and numerical results where the numerical results are obtained by a two-phase flow solver for the full Navier-Stokes equations using the complex extruder geometry.