We investigate the non-isothermal non-Newtonian filling process according to the phase field method in three dimensions. The moving interface between the Newtonian and non-Newtonian fluid is captured by the Cahn-Hilliard equation. Based on phase field parameters, the governing equations of the flow field could be written in a unified form. After that, the Navier-Stokes equations are split into several sub-equations and the FEM and SUPG will be used to handle the appropriate equations. The variation of the viscosity of the polymer melt is described via the Cross-WLF model. The thin wall rectangular cavities with and without obstacles are considered to illustrate the convergence, robustness and accuracy of the numerical algorithm. The influences of the inlet velocity and the size of the injection gate on the filling process are analyzed. The numerical results agree well with the experimental data and also exhibit good mass conservation properties.

The complicated gas entrapment problem in polymer filling process is studied. The moving melt interface is captured with a level set method. An XPP (eXtended Pom-Pom) constitutive model is utilized for the description of viscoelastic fluid. The governing equations of flow field are solved with a coupled continuous and discontinuous Galerkin method. The XPP constitutive equation, level set and its re-initialization equations are solved with an implicit discontinuous Galerkin method. Good agreement between experimental and numerical results illustrates validity of the combined algorithm. Influence of injection velocity and gate size on gas entrapment in a cavity with irregular insert was investigated. Entrapped gas is easier to appear as the injection velocity is higher and the gate size is smaller.