Transient solutions of the dynamics of film casting process using a 2-D viscoelastic model

The nonlinear transient dynamics and stability of a two-dimensional (2-D) model of the isothermal film casting process have been investigated using newly devised simulation techniques employing finite element methods (FEM), which can incorporate the viscoelastic nature of polymer melts as well as the Newtonian features of other fluids. To effectively solve the time-dependent free surface problem of this system, the Arbitrary Lagrangian Eulerian (ALE) algorithm together with a spine method well-suited for free surface tracking was incorporated. Adopting robust numerical stabilization techniques for the hyperbolic system of extensional deformation processes in this study, the transient dynamic behavior of viscoelastic fluids in the 2-D film casting process are presented for the first time in the literature. It is also demonstrated that simulation models in the present study can successfully describe the basic flow behavior of the system including the three instability modes therein, i.e., draw resonance, neck-in, and development of edge beads.