A note on the numerical treatment of the thermally developing flow in screw extruders

This paper proposes a new solution for the problem of thermally developing flow in a single‐screw extruder with power law fluids. It is shown that a transformation to a Lagrangean frame enables one to extend the solution to extrusion situations where appreciable “pressure back flow” exists. The utility of the model is demonstrated using a polystyrene melt as a model fluid.