Steady flow of Bingham plastic fluids past an elliptical cylinder

•Yield-stress suppresses flow separation.•Yielded-regions diminish with increasing yield stress.•Shape of the cylinder strongly influences wake formation.•Inertial effects cause flow separation. In the present work, the flow of Bingham plastic fluids past an elliptical cylinder has been investigated...

Full description

Saved in:
Bibliographic Details
Published in:Journal of non-Newtonian fluid mechanics 2013-12, Vol.202, p.32-53
Main Authors: Patel, S.A., Chhabra, R.P.
Format: Article
Language:English
Subjects:
Aspect ratio
Bingham number
Bingham plastic fluid
Computational fluid dynamics
Cylinders
Drag coefficient
Elliptical cylinder
Elliptical cylinders
Fluid flow
Mathematical analysis
Mathematical models
Reynolds number
Yielded/unyielded zones
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:•Yield-stress suppresses flow separation.•Yielded-regions diminish with increasing yield stress.•Shape of the cylinder strongly influences wake formation.•Inertial effects cause flow separation. In the present work, the flow of Bingham plastic fluids past an elliptical cylinder has been investigated numerically elucidating the effect of yield stress and fluid inertia on the momentum transfer characteristics at finite Reynolds numbers for a 100-fold variation in the aspect ratio. The governing differential equations have been solved over wide ranges of Reynolds number (0.01⩽Re⩽40) and Bingham number (0.01⩽Bn⩽100) in the laminar flow regime employing the finite element method. Furthermore, the effect of the aspect ratio (E) of the elliptical cylinder on the detailed flow characteristics has been studied by varying it from E=0.1 to E=10 thereby spanning varying levels of streamlining of the submerged object. In particular, new extensive results on streamline contours, shape and size of yielded/unyielded regions, shear rate profiles, surface pressure distribution and drag coefficient as functions of the Reynolds number, Bingham number and aspect ratio are presented and discussed. The functional dependence of the individual and total drag coefficients on the governing dimensionless parameters, aspect ratio, Reynolds number and Bingham number, is explored. The present results reveal a significant influence of the shape of the cylinder, i.e., aspect ratio on the detailed flow patterns and the overall hydrodynamic flow behavior of elliptical cylinders.
ISSN:0377-0257
1873-2631
DOI:10.1016/j.jnnfm.2013.09.006