Repositório Digital

A- A A+

Galerkin least-squares solutions for purely viscous flows of shear-thinning fluids and regularized yield stress fluids

.

Galerkin least-squares solutions for purely viscous flows of shear-thinning fluids and regularized yield stress fluids

Mostrar registro completo

Estatísticas

Título Galerkin least-squares solutions for purely viscous flows of shear-thinning fluids and regularized yield stress fluids
Autor Zinani, Flávia Schwarz Franceschini
Frey, Sérgio Luiz
Abstract This paper aims to present Galerkin Least-Squares approximations for flows of Bingham plastic fluids. These fluids are modeled using the Generalized Newtonian Liquid (GNL) constitutive equation. Their viscoplastic behavior is predicted by the viscosity function, which employs the Papanastasiou’s regularization in order to predict a highly viscous behavior when the applied stress lies under the material’s yield stress. The mechanical modeling for this type of flow is based on the conservation equations of mass and momentum, coupled to the GNL constitutive equation for the extra-stress tensor. The finite element methodology concerned herein, the well-known Galerkin Least-Squares (GLS) method, overcomes the two greatest Galerkin shortcomings for mixed problems. There is no need to satisfy Babuška-Brezzi condition for velocity and pressure subspaces, and spurious numerical oscillations, due to the asymmetric nature of advective operator, are eliminated. Some numerical simulations are presented: first, the lid-driven cavity flow of shear-thinning and shear-thickening fluids, for the purpose of code validation; second, the flow of shear-thinning fluids with no yield stress limit, and finally, Bingham plastic creeping flows through 2:1 planar and axisymmetric expansions, for Bingham numbers between 0.2 and 133. The numerical results illustrate the arising of two distinct unyielded regions: one near the expansion corner and another along the flow centerline. For those regions, velocity and pressure fields are investigated for the various Bingham numbers tested.
Contido em Journal of the Brazilian Society of Mechanical Sciences and Engineering. Rio de Janeiro, RJ. Vol. 29, no. 4, (Oct./Dec. 2007), 432-443
Assunto Elementos finitos
Mecanica dos fluidos
Viscoplasticidade
[en] Bingham plastic
[en] Carreau fluids
[en] Galerkin Least-Squares
[en] Papanastasiou’s approximation
[en] Yield Stress
Origem Nacional
Tipo Artigo de periódico
URI http://hdl.handle.net/10183/75798
Arquivos Descrição Formato
000640856.pdf (614.1Kb) Texto completo (inglês) Adobe PDF Visualizar/abrir

Este item está licenciado na Creative Commons License

Este item aparece na(s) seguinte(s) coleção(ões)


Mostrar registro completo

Percorrer



  • O autor é titular dos direitos autorais dos documentos disponíveis neste repositório e é vedada, nos termos da lei, a comercialização de qualquer espécie sem sua autorização prévia.
    Projeto gráfico elaborado pelo Caixola - Clube de Criação Fabico/UFRGS Powered by DSpace software, Version 1.8.1.