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31. |
FLUCTUATION-FLIPPING ORBITS OF FREELY-DRAINING RIGID DUMBBELLS IN CONVERGING-DIVERGING PORE FLOWS |
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Chemical Engineering Communications,
Volume 148-150,
Issue 1,
1996,
Page 593-621
LUDWIGC. NITSCHE,
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摘要:
This paper addresses the deterministic translational-rotational motion of a freely-draining rigid dumbbell that is freely suspended in pressure-driven Stokes flow through a periodically corrugated pore or channel. As is demonstrated by numerical integration of the coupled, nonlinear equations of motion within a sinusoidally corrugated, axisymmetric pore, passage of the dumbbell through successive converging and diverging local flow environments engenders rotary fluctuations relative to the local streamlines that gradually increase in amplitude, over many pore wavelengths, until it eventually flips over. Then the dumbbell slowly realigns itself with the flow, with diminishing fluctuations-whereupon the whole cycle begins again.
ISSN:0098-6445
DOI:10.1080/00986449608936535
出版商:Taylor & Francis Group
年代:1996
数据来源: Taylor
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32. |
ON BROWNIAN DYNAMICS WITH HYDRODYNAMIC WALL EFFECTS: A PROBLEM IN DIFFUSION NEAR A FIBER, AND THE MEANING OF THE NO-FLUX BOUNDARY CONDITION |
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Chemical Engineering Communications,
Volume 148-150,
Issue 1,
1996,
Page 623-651
JOHANNESM. NITSCHE,
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PDF (847KB)
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摘要:
An analysis is presented of the steady-state diffusion of spherical Brownian partcles through an effectively infinite expanse of fluid perforated by a circular cylindrical fiber. Detailed Stokes-flow calculations quantify the solute-fiber hydrodynamic interaction in three regimes covering the full range of solute-fiber separations, and lead to an approximate expression for the position-dependent diffusion dyadic. Thereafter, solution of the pertinent Brownian dynamic problem yields the perturbation caused by the fiber to a linear variation of the solute concentration. The results illustrate a general conclusion, derivable by simple scaling arguments, that the normal derivative of the solute concentration must tend to zero with decreasing solute-wall gap ε as [ln(1/ε)]−1
ISSN:0098-6445
DOI:10.1080/00986449608936536
出版商:Taylor & Francis Group
年代:1996
数据来源: Taylor
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33. |
SINGLE FLUID FLOW IN POROUS MEDIA |
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Chemical Engineering Communications,
Volume 148-150,
Issue 1,
1996,
Page 653-732
SHIJIE LIU,
JACOBH. MASLIYAH,
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PDF (2566KB)
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摘要:
A comprehensive study on single fluid flow in porous media is carried out. The volume averaging technique is applied to derive the governing flow equations. Additional terms appear in the averaged governed equations related to porosity ε, tortuosity τ, shear factorFand hydraulic dispersivityDh. These four parameters are uniquely contained in the volume averaged Navier-Stokes equation and not all of them are independent. The tortuosity can be related to porosity through the Brudgemann equation, for example, for unconsolidated porous media.
ISSN:0098-6445
DOI:10.1080/00986449608936537
出版商:Taylor & Francis Group
年代:1996
数据来源: Taylor
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