Nonuniversal velocity fluctuations of sedimenting particles


Tee, S. Y. ; Mucha, P. J. ; Cipelletti, L. ; Manley, S. ; Brenner, M. P. ; Segre, P. N. ; Weitz, D. A. Nonuniversal velocity fluctuations of sedimenting particles. Physical Review Letters 2002, 89. Copy at
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Velocity fluctuations in sedimentation are studied to investigate the origin of a hypothesized universal scale [P. N. Segre, E. Herbolzheimer, and P. M. Chaikin, Phys. Rev. Lett. 79, 2574 (1997)]. Our experiments show that fluctuations decay continuously in time for sufficiently thick cells, never reaching steady state. Simulations and scaling arguments suggest that the decay arises from increasing vertical stratification of particle concentration due to spreading of the sediment front. The results suggest that the velocity fluctuations in sedimentation depend sensitively on cell geometry.


Times Cited: 54

Last updated on 03/20/2014