Steady and unsteady laminar flows of Newtonian and generalized Newtonian fluids in a planar T- junction.

• Type: Article in International Scientific Journal
• Date: 2008

Authors

A. I. P. Miranda (Author) Other; P. J. Oliveira (Author) Other; F. T. Pinho (Author) FEUP

Journal

Title: International Journal for Numerical Methods in Fluids

Vol. 57

Pages: 295-328

ISSN: 0271-2091

Publisher: Wiley-Blackwell

Indexing

ISI Web of Knowledge - 22 Citations

ISI Web of Science

Scopus - 34 Citations

COMPENDEX

Scientific classification

FOS: Engineering and technology > Chemical engineering

CORDIS: Technological sciences

Other information

Authenticus ID: P-003-ZB1

DOI: 10.1002/fld.1626

Abstract (EN): An investigation of laminar steady and unsteady flows in a two-dimensional T-junction was carried out for Newtonian and a non-Newtonian fluid analogue to blood. The flow conditions considered are of relevance to hemodynamical applications and the localization of coronary diseases, and the main objective was to quantify the accuracy of the predictions and to provide benchmark data that are missing for this prototypical geometry. Under steady flow, calculations were performed for a wide range of Reynolds numbers and extraction flow rate ratios, and accurate data for the recirculation sizes were obtained and are tabulated. The two recirculation zones increased with Reynolds number, but the behaviour was non-monotonic with the flow rate ratio. For the pulsating flows a periodic instability was found, which manifests itself by the breakdown of the main vortex into two pieces and the subsequent advection of one of them, while the secondary vortex in the main duct was absent for a sixth of the oscillating period. Shear stress maxima were found on the walls opposite the recirculations, where the main fluid streams impinge onto the walls. For the blood analogue fluid, the recirculations were found to be 10% longer but also short lived than the corresponding Newtonian eddies, and the wall shear stresses are also significantly different especially in the branch duct.

Language: English

Type (Professor's evaluation): Scientific