NUMERICAL-SIMULATION METHOD FOR VISCOELASTIC FLOWS WITH FREE SURFACES- FRINGE ELEMENT GENERATION METHOD

To simulate filling flow in injection moulding for viscoelastic fluids , a numerical method, based on a finite element method and a finite vo lume method, has been developed for incompressible isothermal viscoela stic flow with moving free surfaces. The advantages of this method are , first, good applicability to arbitrarily shaped mould geometries and , second, accurate treatment for boundary conditions on the free surfa ce. Typical filling flows are simulated, namely filling flow into a 1: 4 expansion cavity with and without an obstacle. Numerical results pre dict the position of weld lines and air-traps. The method also indicat es the effects of elongational flow on molecular orientation.