A second-order algorithm for predicting temperature-dependent viscous flow and viscous dissipation effects on extrudate swell

This study advances our previous fixed-domain problem by applying a time-marching semi-implicit Taylor-Galerkin/pressure correction algorithm to the realm of the free-surface flow of incompressible, inelastic fluids that obey an exponential temperature dependence of viscosity. The work incorporates Arbitrary Lagrangian-Eulerian techniques, which are combined with the kinetic equation within the algorithm. The main focus is on the impact of changes in flow properties on the position/shape of the free surface and response in extrudate swell. We investigate flows both with and without considering the temperature dependence of viscosity and the viscous dissipation term under heating and cooling conditions. Neglecting either factor results in underestimations of heat transfer and pressure drop, which subsequently influence the extrusion swelling ratio. Further-more, we examine the impacts of inertia and the Peclet number. The numerical results were validated by comparing them with reference data from the scientific literature.