Modelling of polymer fluid flow and residence time distribution in twin screw extruder using fictitious domain method

Abstract

The flow behaviour of a polymer melt in the conveying region of an intermeshing corotating twin screw extruder was studied using the combination of mixed finite element and fictitious domain method. The model was a combination of the governing equations of continuity and momentum with Carreau rheological model in a three-dimensional Cartesian coordinate system. The equations were solved by the use of a mixed Galerkin finite element technique. The Picard's iterative procedure was used to handle the non-linear nature of the derived equations. The particle tracking technique was used to obtain residence time distribution and analyse distributive mixing in conveying region. The shear rate distribution was investigated as a criterion for dispersive mixing. The applicability of this model was verified by the comparison of experimentally measured pressure and simulation results for high density polyethylene melt. This comparison shows that there is a good adequacy between experimental data and model predictions.

Non‐Isothermal Modeling of a Non‐Newtonian Fluid Flow in a Twin Screw Extruder Using the Fictitious Domain Method

“…[19] The temperature distribution on cross sections of flow domain in the TSE at different axial distance for screw speed of 60 rpm has been presented in Figure 12. It was shown, the temperature varies at different positions of flow domain and reaches to maximum values in both the intermeshing and screws tip regions.…”

“…[23] In our previous work, we developed a mathematical model for isothermal simulation of the polymeric fluid flow in order to investigate the mixing efficiency and residence time distribution in TSE. [19] In this work, we have developed our modeling for non-isothermal polymeric fluids flow. Therefore, our focus is on the 3D non-isothermal simulation of the polymeric fluid flow in conveying region of a corotating TSE.…”

“…In our previous work, the isothermal behavior of polymer melt in the conveying region of a TSE was simulated based on the combination of mixed finite element and fictitious domain methods . In this research, we have developed this technique for non‐isothermal modeling of a non‐Newtonian fluids flow in TSEs.…”

“…In our previous work, we developed a mathematical model for isothermal simulation of the polymeric fluid flow in order to investigate the mixing efficiency and residence time distribution in TSE . In this work, we have developed our modeling for non‐isothermal polymeric fluids flow.…”

Online Monitoring of the Degree of Fill in a Rotating Full‐Flight Screw of a Corotating Twin‐Screw Extruder

“…As a fundamental research on the flow characteristics of TSEs, many studies have been carried out on the measurement of resin pressure at the barrel surface, the residence time distribution, and the resin temperature of the molten resin along the extrudate direction . However, there are few studies measuring the degree of fill of the resin in the TSEs.…”