Pressure losses in the laminar flow of shear-thinning power-law fluids across a sudden pipe expansion.

• Tipo: Artigo em Revista Científica Internacional
• Data: 2003

Autores

Fernando T. Pinho (Autor) FEUP; P. J. Oliveira (Autor) Outra; J. P. Miranda (Autor) Outra

Revista

Título: International Journal of Heat and Fluid Flow

Vol. 24

Páginas: 747-761

ISSN: 0142-727X

Editora: Elsevier

Indexação

ISI Web of Science

Outras Informações

DOI: 10.1016/S0142-727X(03)00083-3

Abstract (EN): A numerical investigation was carried out to study the laminar non-Newtonian flow through an axisymmetric sudden expansion having a diameter ratio of 1 to 2.6. The fluids were inelastic and shear thinning with a viscosity obeying the power law model. The recirculation length and strength and, most importantly, the local loss coefficient CI were quantified as a function of the inlet pipe Reynolds number and shear-thinning intensity. When using the generalised Reynolds number introduced by Metzner and Reed [AIChEJ 1 (1955) 434] (Regen), at low Reynolds numbers CI increased by more than 100% when n varied from 1.0 to 0.2, whereas CI decreased by more than 50% at high Reynolds numbers. However, this feature was shown to be related to the definition of the Reynolds number. A correlation between CI, Regen and n is presented at the end. 2003 Elsevier Inc. All rights reserved.

Idioma: Inglês

Tipo (Avaliação Docente): Científica

Nº de páginas: 15