Journal ArticleDOI
The Flow of a Viscous Fluid Past an Inhomogeneous Porous Cylinder
M. P. Singh,J. L. Gupta +1 more
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In this article, the slow stationary motion of a uniformly flowing viscous fluid past a circular porous inhomogeneous cylinder of radius (a + b) is considered, and the solution to the system of equations is obtained by the construction and suitable matching of four simultaneous asymptotic expansions: innermost expansion valid in the region 0 ≦ r' ≦ a, interior expansion valid at the region a = r' = b and the usual inner (Stokes) and outer (Oseen) expansions.Abstract:
The slow stationary motion of a uniformly flowing viscous fluid past a circular porous inhomogeneous cylinder of radius (a + b) is considered. The problem is fully described by the Darcy law, which holds good in the region inside the body, the Navier-Stokes equations, describing the flow field outside the body, the continuity conditions and the suitable boundary conditions. The solution to the system of equations is obtained by the construction and suitable matching of four simultaneous asymptotic expansions: inner-most expansion valid in the region 0 ≦ r' ≦ a, interior expansion valid in the region a ≦ r' ≦ (a + b) and the usual inner (Stokes) and outer (Oseen) expansions. The drag formula is expressed in terms of an equivalent permeability. The effect of permeability on the drag is that it reduces the effective radius of the cylinder by a factor exp [–∽KT'/(a + b)2]. Several special cases have been considered.
In der vorliegenden Arbeit wird die langsame stationare Stromung einer gleichmasig fliesenden zahen Flussigkeit um einen inhomogenen porosen Kreiszylinder vom Radius a + b betrachtet. Das Problem wird insgesamt durch das im Innern des Korpers gut erfullte Darcysche Gesetz, die das Stromungsfeld auserhalb des Korpers beschreibenden Navier-Stokes-Gleichungen, die Kontinuitatsbedingungen und die passenden Randbedingungen erfast. Die Losung des entstehenden Gleichungssystems wird durch die Konstruktion und geeignete Anpassung von vier simultanen, asymptotischen Entwicklungen erhalten: eine fur den innersten Bereich 0 ≦ r' ≦ a gultige Entwicklung, eine Entwicklung fur den inneren Bereich a ≦ r' ≦ a + b und die gewohnlichen Entwicklungen nach Stokes bzw. Oseen fur den randnahen bzw. den Fernbereich. Die Widerstandsformel wird mittels einer aquivalenten Permeabilitat ausgedruckt. Als Wirkung der Permeabilitat auf den Widerstand ergibt sich eine Reduzierung des effektiven Zylinderradius um einen Faktor exp [– ∽KT'/(a + b)2]. Es werden mehrere Spezialfalle untersucht.read more
Citations
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Journal ArticleDOI
On boundary conditions for fluid flow in porous media
TL;DR: In this article, boundary conditions at the surface between a porous medium and a free fluid flow were studied. And the results about the matching of different flow regions and boundary conditions are given, as well as examples.
Journal ArticleDOI
Motion through a non-homogeneous porous medium: Hydrodynamic permeability of a membrane composed of cylindrical particles
TL;DR: In this paper, the effect of various fluid parameters on the flow of a viscous steady incompressible fluid through a non-homogeneous porous medium is discussed, and the effects of these parameters on streamlines flow patterns are also discussed.
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The hemodynamic forces acting on thrombi, from incipient attachment of single cells to maturity and embolization
TL;DR: The interior forces are then due solely to hydrostatic pressure and initially vary directly with vt/Dt and inversely with thrombus height Hp, thus favouring embolization at an early stage and in arterial systems.
Journal ArticleDOI
Slow viscous flow through a membrane built up from porous cylindrical particles with an impermeable core
TL;DR: In this paper, the slow viscous flow through an aggregate of concentric clusters of porous cylindrical particles with Happel boundary condition is considered, and the results obtained through this model can be useful to study the membrane filtration process.
Journal ArticleDOI
Flow of Viscous Fluid at Small Reynolds Numbers past a Porous Sphere
TL;DR: In this article, the authors considered the flow of viscous fluid past a porous and permeable body of arbitrary but smooth shape, and investigated the asymptotic behavior of the flow tor small permeability of the porous medium.
References
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Journal ArticleDOI
Expansions at small Reynolds numbers for the flow past a sphere and a circular cylinder
Ian Proudman,J. R. A. Pearson +1 more
TL;DR: In this paper, the Navier-Stokes equation is replaced by a set of differential equations for the coefficients ψn and Ψn, but only one set of physical boundary conditions is applicable to each expansion (the no-slip conditions for the Stokes expansion, and the uniform-stream condition for the Oseen expansion).
Journal ArticleDOI
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Journal ArticleDOI
The Effect of Permeability on the Slow Motion of a Porous Sphere in a Viscous Liquid
Daniel D. Joseph,L. N. Tao +1 more
TL;DR: In this paper, the effects of permeable materials on the low Reynolds number flow of viscous liquids may be evaluated by using Darcy's law and the asymptotic equations (Re O) of Stokes.
Journal ArticleDOI
Two Generalizations of the Stokes Formula for a Porous Sphere
TL;DR: In this paper, a slow stationary motion of a uniformly flowing viscous liquid in the presence of a porous sphere is considered and the formulae obtained for the forces acting on the sphere generalize the results obtained previously for a porous homogeneous sphere under the validity of Darcy's law.
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