NUMERICAL SIMULATION
METHOD FOR VISCOELASTIC FLOWS WITH FREE SURFACES - FRINGE ELEMENT GENERATION
METHOD
TORU SATO* AND STEPHEN M. RICHARDSON
Department of Chemical Engineering and
Chemical Technology,
Imperial College, London SW7 2BY, U.K.
SUMMARY
To simulate filling flow in
injection moulding for viscoelastic fluids, a numerical method, based on a
finite element method and a finite volume method, has been developed for
incompressible isothermal viscoelastic 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
surface. Typical filling flows are simulated, namely: filling flow into a 1:4
expansion cavity with and without an obstacle. Numerical results predict the
position of weld lines and air-traps. The method also indicates the effects of
elongational flow on molecular orientation.
KEY WORDS: Finite element/finite volume method, Free
surface, Viscoelastic flow, Injection moulding
