Dynamical simulations of sedimenting spheres

Journal Article · Mon Feb 01 04:00:00 EST 1993 · Physics of Fluids A; (United States)

DOI:https://doi.org/10.1063/1.858695· OSTI ID:6832832

Ladd, A J.C. ^[1]

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1. Lawrence Livermore National Laboratory, Livermore, California 94550 (United States)

The sedimentation of monodisperse suspensions of rigid spheres has been studied by dynamical simulation; computational techniques are described and numerical results are reported. It has been found that there is a slow relaxation of the suspension microstructure during sedimentation, so that compared with the initial equilibrium distribution, there is an increased number of pairs of particles near contact; this leads to a 5%--10% increase in the average sedimentation velocity. Individual particle velocities fluctuate about the mean fall speed; these fluctuations are large and persist for long times. The resulting hydrodynamically induced dispersion of the particles can be characterized by strongly anisotropic diffusion coefficients; however, the dispersion process is non-Fickian at high solids concentrations.

• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 6832832
• Journal Information: Physics of Fluids A; (United States), Journal Name: Physics of Fluids A; (United States) Vol. 5:2; ISSN PFADEB; ISSN 0899-8213
• Country of Publication: United States
• Language: English

Related Subjects

661300* -- Other Aspects of Physical Science-- (1992-)
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
COMPUTERIZED SIMULATION
CRYSTAL STRUCTURE
DISPERSIONS
FLUCTUATIONS
MICROSTRUCTURE
RELAXATION TIME
SEDIMENTATION
SIMULATION
SPHERES
SUSPENSIONS
VARIATIONS