A finite element method for computing the flow of multi-mode viscoelastic fluids: comparison with experiments

Mixed finite element methods for viscoelastic flow analysis: a review

“…The form of the damping function did not give independent control over shear and elongational data necessary to describe the behavior of the other grade (Rigidex). Recently, Beraudo et al [153] have also reported results on contraction flows of LDPE melts and made comparison with experimentally observed birefringence patterns.…”

Prediction of extrudate swell in polymer melt extrusion using an Arbitrary Lagrangian Eulerian (ALE) based finite element method

“…The PTT model was used to describe the melt, and its parameters were determined by fitting to rheological data [16]. All meshes were non-uniform and graded with smaller elements at the die exit where singularity exists.…”

“…Many of these early numerical simulations were undertaken using the upper-convected Maxwell (UCM) constitutive equation [3,4]. Later, more realistic constitutive equations such as the integral K-BKZ model [5][6][7][8][9][10][11][12][13] and the differential PTT model [14][15][16] were used. Different types of damping functions such as the Wagner irreversible and reversible [9][10][11] damping functions, the Papanastasiou-Scriven-Macosko (PSM) type damping function [5][6][7][8], the Osaki twin exponential damping function [17] and a new three-parameter damping function suggested by Huang and Lu [13], have been used in conjunction with the K-BKZ model to study the effect of rheological non-linearities on extrudate swell.…”

“…An example of a detailed study is that of Béraudo et al [16], who addressed the issue of over-prediction of extrudate swell by using a multi-mode PTT model containing a slip parameter ( ). The model parameters were obtained from fitting to shear and extensional data for LLDPE and LDPE melts.…”

“…For LDPE melt, W-shaped fringes were observed right after the downstream channel entrance. Béraudo et al [16] simulated the 2D flow using a finite element method based on Newton's iterative scheme and discontinuous approximations of the extra-stress tensor. The discontinuous interpolation allows elimination of stress variable at element level by means of a static condensation technique.…”