Journal ArticleDOI
The Axisymmetric Sudden Expansion Flow of a Non-Newtonian Viscoplastic Fluid
G. C. Vradis,M. V. Ötügen +1 more
TLDR
In this paper, the flow of a non-Newtonian viscoplastic Bingham fluid over an axisymmetric sudden expansion is studied by numerically solving the governing fullyelliptic continuity and momentum equations.Abstract:
The flow of a non-Newtonian viscoplastic Bingham fluid over an axisymmetric sudden expansion is studied by numerically solving the governing fully-elliptic continuity and momentum equations. Solutions are obtained for a wide range of Reynolds and yield numbers in the laminar flow regime with constant fluid properties. The preset work demonstrates that the finite-difference technique can successfully be employe to obtain solutions to separating/reattaching internal flows of Bingham plastics. The results demonstrate the strong effects of the yield and Reynolds numbers on both th integral and the local structure of the separating and reattaching flow. Higher yield numbers result in larger overall effective viscosities and thus faster flow recover downstream of the sudden expansion. The reattachment length decreases with increas ing yield numbers, eventually reaching an asymptotic nonzero value which, in turn, is dependent on the Reynolds number. The strength of the recirculating flow also decreases with increasing yield numbers.read more
Citations
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Steady Herschel–Bulkley fluid flow in three-dimensional expansions
TL;DR: In this article, the steady flow of Herschel-Bulkley fluids in a canonical three-dimensional expansion was modeled using a regularized continuous constitutive relation, and the flow was obtained numerically using a mixed-Galerkin finite element formulation with a Newton-Raphson iteration procedure coupled to an iterative solver.
Journal ArticleDOI
Flow of viscoplastic liquids through axisymmetric expansions-contractions
TL;DR: In this article, the internal flow of viscoplastic liquids through ducts consisting of an abrupt axisymmetric expansion followed by an abrupt contraction was examined, and steady, inertialess numerical solutions were obtained by solving the conservation equations of mass and momentum via the finite volume method.
Journal ArticleDOI
Flow development of Herschel–Bulkley fluids in a sudden three-dimensional square expansion
TL;DR: In this paper, the authors studied the flow development of Herschel-Bulkley fluids in a sudden three-dimensional square expansion using the mixed-Galerkin finite element formulation to solve the conservation of mass and momentum equations.
Journal ArticleDOI
Hydrodynamics and Metzner-Otto correlation in stirred vessels for yield stress fluids
TL;DR: In this paper, the hydrodynamics and power consumption in laminar stirred vessel flow using numerical computation were investigated and the Metzner-Otto correlation was established for mixing in power-law fluids.
Journal ArticleDOI
Pressure losses in the laminar flow of shear-thinning power-law fluids across a sudden axisymmetric expansion
TL;DR: In this article, 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.
References
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Journal ArticleDOI
Flow of bingham fluids in complex geometries
G. Glenn Lipscomb,Morton M. Denn +1 more
TL;DR: Bingham fluids cannot contain yield surfaces in complex confined geometries like those used in molding and lubrication, and flow must occur everywhere, although shear-free plug regions may sometimes be approximated as mentioned in this paper.
Journal ArticleDOI
Computational and experimental study of a captive annular eddy
Enzo O. Macagno,Tin-Kan Hung +1 more
TL;DR: In this article, the main flow and the captive eddy between it and the walls are analyzed, and it is concluded that the main role of the eddy is to shape the flow with a rather small energy exchange.
Journal ArticleDOI
Numerical study of the Bingham squeeze film problem
E.J. O'Donovan,Roger I. Tanner +1 more
TL;DR: In this paper, the authors re-exemined the problem using a finite element program and concluded that a small plug of unyielded fluid exists adjacent to the centre of the plates.
Journal ArticleDOI
Pressure-flow relations of human blood in hollow fibers at low flow rates
TL;DR: It was found that red cell suspensions exhibit a yield shear stress only if the plasma protein fibrinogen is present and blood flow in hollow fibers were in excellent agreement with rotational viscometer measurements and with analytical predictions based on the assumptions that blood flows as a homogeneous continuum and that the velocity at the wall is zero.