The numerical modeling and study of gas entrapment phenomenon in non-isothermal polymer filling process

Abstract

• The problem of gas entrapment in the non-isothermal polymer filling process is simulated. • The finite element method coupled with implicit discontinuous Galerkin method is developed for the simulation. • The influence of injection velocity and gate size on the gas entrapment phenomenon have been analyzed. In this paper, the intricate gas entrapment phenomenon in the non-isothermal polymer filling process is investigated via a combined finite element and discontinuous Galerkin numerical algorithm. The evolving melt interface is captured via level set method and the eXtended Pom-Pom (XPP) constitutive model is employed to describe the viscoelastic fluid. The governing equations of flow field are solved via a coupled continuous and discontinuous Galerkin method. The implicit discontinuous Galerkin method is utilized for the solution of the XPP constitutive equation, level set and its re-initialization equations. The good agreement of experimental and simulation results illustrates the validity of this combined computational algorithm. The influence of injection velocity and the gate size on the gas entrapment phenomenon are both studied in the irregular cavity with complex insert. We have found that the entrapped gas is easy to appear for the case of higher injection velocity and smaller gate size. The distribution of temperature field in different cases are also shown.