A Finite Element Model of a White-Metzner Viscoelastic Polymer Extrudate.
AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH
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A finite element model of a viscoelastic polymer melt characterized by a White-Metzner rheological equation of state was developed. For creeping flow wherein the inertia terms are negligible non-linear finite element equations were solved by a method of direct substitution termed Picard iteration. Four flow geometries were examined cross channel, plane couette, entry, and step flow. A comparison of two bi-quadradic isoparametric element types 8 node serendipity and 9 node Lagrange showed general superior behavior of the Lagrange elements. The penalty method of incompressible flow was used with the Galerkin method to formulate the finite element equation, yielding satisfactory behavior for creeping inelastic and viscoelastic flow. The non-linear equations yielded numerical convergence up to Weissenberg numbers of 0.01. Techniques of expanding this radius of convergence were examined and proposed for future effort. Author
- Theoretical Mathematics