Numerical simulation of fluid flow and heat transfer in twin‐screw extruders for non‐Newtonian materials

A new simplified approach has been proposed for the numerical simulation of the thermal transport in corotating, tangential, and self‐wiping twin‐screw extruders. It is assumed that the flow domain in a twin‐screw extruder can be divided into (i) the translation region (T‐region), which represents a flow similar to that in a single‐screw channel and (ii) the intermeshing region (I‐region), which is located between the two screws. The two regions are simulated separately and then coupled for each screw section to model the overall transport in tangential and self‐wiping twin‐screw extruders. A finite difference method is employed for the developing flow and temperature fields in the T‐region, in order to minimize the computing effort, while a finite element method is employed for determining the interchannel flow mixing and the thermal transport in the I‐region. Results are obtained in terms of temperature, velocity, and pressure variations along the screw channels and mixing between the two screws.