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Inside the moving layer of a sheared granular bed

Published online by Cambridge University Press:  01 June 2009

H. MOUILLERON
Affiliation:
Institut de Mécanique des Fluides de Toulouse, Université de Toulouse, 2, Allée C. Soula, 31400 Toulouse, France
F. CHARRU*
Affiliation:
Institut de Mécanique des Fluides de Toulouse, Université de Toulouse, 2, Allée C. Soula, 31400 Toulouse, France
O. EIFF
Affiliation:
Institut de Mécanique des Fluides de Toulouse, Université de Toulouse, 2, Allée C. Soula, 31400 Toulouse, France
*
Email address for correspondence: [email protected]

Abstract

The moving layer at the surface of a granular bed sheared by a viscous flow has been investigated experimentally. The fluid and particle velocities have been measured using particle imaging velocimetry (PIV) and particle tracking, respectively, with a technique of matched index of refraction. The mean velocity profiles are found to be parabolic. The models of Bagnold (Phil. Trans. R. Soc. Lond. A, vol. 249, 1956, pp. 235–297) and Leighton & Acrivos (Chem. Engng Sci., vol. 41, 1986, pp. 1377–1384) fail to account for the observations. A simplified model assuming uniform particle concentration provides good agreement close to the threshold.

Type
Papers
Copyright
Copyright © Cambridge University Press 2009

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References

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