Three-dimensional non-Newtonian computations of extrudate swell with the finite element method Original Research Article

Numerical simulations have been carried out for the extrudate swell problem in three-dimensional domains. The finite element method is used with streamline elements, which render the calculations fast and efficient for flows through long extrusion dies (no reservoir present). The method is first tested against purely viscous (Newtonian), viscoplastic (Bingham), and slightly viscoelastic (CEF model) results for the determination of extrudate swell from circular dies, which have a two-dimensional counterpart. Full three-dimensional die designs are also studied, such as extrusion from a square and a cross-shaped die.