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Velocity fluctuations in a low-Reynolds-number fluidized bed

Published online by Cambridge University Press:  17 January 2008

SHANG-YOU TEE ,
P. J. MUCHA ,
M. P. BRENNER  and
D. A. WEITZ
SHANG-YOU TEE
Affiliation:
Department of Physics, Harvard University, Cambridge, MA 02138, USA School of Engineering and Applied Science, Harvard University, Cambridge, MA 02138, USA
P. J. MUCHA
Affiliation:
Department of Mathematics & Institute for Advanced Materials, University of North Carolina, Chapel Hill, NC 27599, USA
M. P. BRENNER
Affiliation:
School of Engineering and Applied Science, Harvard University, Cambridge, MA 02138, USA
D. A. WEITZ
Affiliation:
Department of Physics, Harvard University, Cambridge, MA 02138, USA School of Engineering and Applied Science, Harvard University, Cambridge, MA 02138, USA
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Abstract

The velocity fluctuations of particles in a low-Reynolds-number fluidized bed have important similarities and differences with the velocity fluctuations in a low-Reynolds-number sedimenting suspension. We show that, like sedimentation, the velocity fluctuations in a fluidized bed are described well by the balance between density fluctuations due to Poisson statistics and Stokes drag. However, unlike sedimentation, the correlation length of the fluctuations in a fluidized bed increases with volume fraction. We argue that this difference arises because the relaxation time of density fluctuations is completely different in the two systems.

Type
Papers
Information
Journal of Fluid Mechanics , Volume 596 , 25 January 2008 , pp. 467 - 475
Copyright
Copyright © Cambridge University Press 2008

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