English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

The corner vortex phenomenon occurring in entry flow is relevant to both polymer rheology and polymer processing. The famous viscoelastic constitutive equations in numerical computations of fluid mechanics have always had limited relevance at low apparent shear rates. However, three-dimensional (3D) simulations of viscoelastic fluids have been rarely found in advanced rheology. Recently, the GNF-X (eXtended Generalized Newtonian Fluid) constitutive equation of the weighted shear/extensional viscosity developed in advanced rheology of complex fluids has been incorporated into state-of-the-art predictive engineering tools. Thereby, 3D numerical simulations of entry flow were performed for a LDPE (low-density polyethylene) melt. As a validation, the predicted vortex streamlines are in good agreement with related experimental observations. More importantly, the simulation results show the vortex growth with respect to apparent shear rates, contraction ratios, and inlet angles. In particular for extensional viscosity, the stronger extension hardening characteristic yields a large vortex size.

Three-dimensional simulation of vortex growth within entry flow of a polymer melt