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Experimental investigation of the instability of a sedimenting suspension of fibres

Published online by Cambridge University Press:  07 March 2007

BLOEN METZGER ,
JASON E. BUTLER  and
ÉLISABETH GUAZZELLI
BLOEN METZGER
Affiliation:
IUSTI – CNRS UMR 6595, Polytech' Marseille, Technopôle de Château-Gombert, 13453 Marseille cedex 13, France
JASON E. BUTLER
Affiliation:
Department of Chemical Engineering, The University of Florida, Gainesville, FL 32611-6005, USA
ÉLISABETH GUAZZELLI
Affiliation:
IUSTI – CNRS UMR 6595, Polytech' Marseille, Technopôle de Château-Gombert, 13453 Marseille cedex 13, France
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Abstract

Observations of the flow structures formed by rigid fibres of high aspect ratio sedimenting within a viscous fluid at a Reynolds number of approximately 10−4 confirm the existence of an instability as reported in previous theories, experiments, and numerical simulations. Using data generated from particle image velocimetry measurements, we quantify the sedimentation structures over a wide range of parameters, which include the height of fluid, cross-section of the sedimentation cell, fibre dimensions, fluid properties, and volume fractions ranging from dilute to semi-dilute. Alternating structures of streamers and backflow regions which span the height of the sedimentation cell form at short times and transition from large wavelengths to smaller wavelength as the sedimentation proceeds. No simple dependence of the horizontal wavelength on the length scales and concentration was observed in the experiments, suggesting the need for additional analysis. We also report the mean velocities and velocity fluctuations; the strength of the velocity fluctuations strongly correlates with the size of the vertical component of the sedimentation structure. Measurements of the orientation distribution, using an efficient and newly employed technique, agree with previously published results. A movie is available with the online version of the paper.

Type
Papers
Information
Journal of Fluid Mechanics , Volume 575 , March 2007 , pp. 307 - 332
Copyright
Copyright © Cambridge University Press 2007

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References

REFERENCES

Bergougnoux, L., Ghicini, S., Guazzelli, E. & Hinch, E. J. 2003 Spreading fronts and fluctuations in sedimentation. Phys. Fluids 15, 1875–1887.CrossRefGoogle Scholar
Butler, J. E. & Shaqfeh, E. S. G. 2002 Dynamic simulations of the inhomogeneous sedimentation of rigid fibres. J. Fluid Mech. 468, 205–237.CrossRefGoogle Scholar
Chaouche, M. & Koch, D. L. 2001 Rheology of non-Brownian rigid fibre suspensions with adhesive contacts. J. Rheol. 45, 369–382.CrossRefGoogle Scholar
Davis, R. H. & Acrivos, A. 1985 Sedimentation of noncolloidal particles at low Reynolds number. Annu. Rev. Fluid Mech. 17, 91–118.CrossRefGoogle Scholar
Davis, R. H. & Hassen, M. A. 1988 Spreading of the interface at the top of a slightly polydisperse sedimenting suspension. J. Fluid Mech. 196, 107–134 and Corrigendum 1989 J. Fluid Mech. 202, 598.CrossRefGoogle Scholar
Herzhaft, B. & Guazzelli, E. 1999 Experimental study of the sedimentation of dilute and semi-dilute suspensions of fibres. J. Fluid Mech. 384, 133–158.CrossRefGoogle Scholar
Herzhaft, B., Guazzelli, E., Mackaplow, M. B. & Shaqfeh, E. S. G. 1996 Experimental investigation of the sedimentation of a dilute fibre suspension. Phys. Rev. Lett. 77, 290–293.CrossRefGoogle ScholarPubMed
Koch, D. L. & Shaqfeh, E. S. G. 1989 The instability of a dispersion of sedimenting spheroids. J. Fluid Mech. 209, 521–542.CrossRefGoogle Scholar
Kumar, P. & Ramarao, B. V. 1991 Enhancement of the sedimentation rates in fibrous suspensions. Chem. Engng Commun. 108, 381–401.CrossRefGoogle Scholar
Kuusela, E., Lahtinen, J. M. & Ala-Nissila, T. 2003 Collective effects in settling of spheroids under steady-state sedimentation. Phys. Rev. Lett. 90, 094502.CrossRefGoogle ScholarPubMed
Mackaplow, M. B. & Shaqfeh, E. S. G. 1998 A numerical study of the sedimentation of fibre suspensions. J. Fluid Mech. 376, 149–182.CrossRefGoogle Scholar
Metzger, B., Guazzelli, E. & Butler, J. E. 2005 Large-scale streamers in the sedimentation of a dilute fibre suspension. Phys. Rev. Lett. 95, 164506.CrossRefGoogle ScholarPubMed
Meunier, P. & Leweke, T. 2003 Analysis and minimization of errors due to high gradients in particle image velocimetry. Exps. Fluids 35, 408–421.CrossRefGoogle Scholar
Nicolai, H., Herzhaft, B., Hinch, E. J., Oger, L. & Guazzelli, E. 1995 Particle velocity fluctuations and hydrodynamic self-diffusion of sedimenting non-Brownian spheres. Phys. Fluids 7, 12–23.CrossRefGoogle Scholar
Saintillan, D., Darve, E. & Shaqfeh, E. S. G. 2005 A smooth particle-mesh Ewald algorithm for Stokes suspension simulations: The sedimentation of fibres. Phys. Fluids 17, 033301.CrossRefGoogle Scholar
Saintillan, D., Shaqfeh, E. S. G. & Darve, E. 2006 The growth of concentration fluctuations in dilute dispersions of orientable and deformable particles under sedimentation. J. Fluid Mech. 553, 347–388.CrossRefGoogle Scholar
Segrè, P. N., Herbolzheimer, E. & Chaikin, P. M. 1997 Long-range correlations in sedimentation. Phys. Rev. Lett. 79, 2574–2577.CrossRefGoogle Scholar
Storkey, A. J., Hambly, N. C., Williams, C. K. I. & Mann, R. G. 2004 Cleaning sky survey databases using Hough transform and renewal string approaches. Mon. Not. R. Astron. Soc. 347, 36–51.CrossRefGoogle Scholar
Turney, M. A., Cheung, M. K., Powell, R. L. & McCarthy, M. J. 1995 Hindered settling of rod-like particles measured with magnetic resonance imaging. AIChE J. 41, 251–257.CrossRefGoogle Scholar

Metzger et al. supplementary movie

Movie 1.Sedimentation of a dilute suspension of fibres. Gravity acts downwards. The fluorescing fibres appear in black within the laser sheet. Experimental conditions: fibres of batch A (nylon, aspect ratio 11), fluid 2 (25% oil, 75% water), cell: 10 x 10 x 60 cm, imaging window of 10 x 8 cm located 10 cm above the cell bottom.

Download Metzger et al. supplementary movie(Video)
Video 27.9 MB

Metzger et al. supplementary movie

Movie 1.Sedimentation of a dilute suspension of fibres. Gravity acts downwards. The fluorescing fibres appear in black within the laser sheet. Experimental conditions: fibres of batch A (nylon, aspect ratio 11), fluid 2 (25% oil, 75% water), cell: 10 x 10 x 60 cm, imaging window of 10 x 8 cm located 10 cm above the cell bottom.

Download Metzger et al. supplementary movie(Video)
Video 9.8 MB