The increasing necessity for use of synthetic polymer products, such as for
production of packaging, parts of appliances, electronics, cars, biomaterials for medical
applications, etc., has led to the polymer industry to seek reduction of waste and increase
product quality and productivity. Consequently, a better understanding of how the
rheological properties of polymers affect their processing and final product quality is of
great importance. In order to obtain faster results with less cost, the studies of modeling and
simulation of polymer processing are increasing every day. This chapter aims to describe
new tools for CFD simulations of viscoelastic fluids, implemented in the OpenFOAM CFD
package due to advantages offered by this software, such as the possibility to use multigrid
techniques and data processing parallelization, besides being a free software and open
source. The constitutive models of Maxwell, UCM, Oldroyd-B, White-Metzner, Giesekus,
Leonov, FENE-P, FENE-CR, linear and exponential PTT, Pom-Pom, XPP and DCPP were
included in the general multimode form. In order to validate the developed solver,
comparisons with numerical and experimental results from literature were carried out. The
results were satisfactory giving credibility to the implemented solver and ensure the
availability of a powerful tool for the study of viscoelastic fluids to be used both in
academia and in industry. An extension of this tool, used for analysis of free-surface
viscoelastic fluid flows using the VOF methodology, is also presented. The die swell
experiment, a classical flow phenomenon used in the rheology literature to present the
concept of viscoelastic effects, was also simulated. The results obtained using Giesekus
model showed the great potential of the developed formulation, once all phenomena
observed experimentally were reproduced in the simulations.
Keywords: Viscoelastic fluids, free surface flow, two-phase flow, finite volumes,
multimode simulation, die swell simulation, differential constitutive equations,
high weissenberg numbers, VOF, CFD, DEVSS, OpenFOAMTM.
