Hostname: page-component-78c5997874-4rdpn Total loading time: 0 Render date: 2024-11-20T04:20:06.064Z Has data issue: false hasContentIssue false

Measurement of shear-induced self-diffusion in concentrated suspensions of spheres

Published online by Cambridge University Press:  21 April 2006

David Leighton
Affiliation:
Department of Chemical Engineering, Stanford University, Stanford, CA 94305–5025, USA Present address: Department of Chemical Engineering, University of Notre Dame, Notre Dame, IN 46556, USA.
Andreas Acrivos
Affiliation:
Department of Chemical Engineering, Stanford University, Stanford, CA 94305–5025, USA

Abstract

A novel technique is presented for determining the coefficient of shear-induced particle self-diffusion in concentrated suspensions of solid spheres, which relies on the fact that this coefficient can be computed from the measured variations in the time taken by a single marked particle in the suspension to complete successive circuits in a Couette device. Since this method does not involve the direct measurement of the lateral position of the marked particle, it requires a much simpler experiment than that used by Eckstein, Bailey & Shapiro (1977) which is shown to be constrained by wall effects at high particle concentration. The diffusion coefficient thus determined was found to be proportional to the product γa2, where γ is the shear rate and a the particle radius, and to have the asymptotic form 0.5γa2ϕ2 in the dilute limit when the particle concentration ϕ → 0.

Type
Research Article
Copyright
© 1987 Cambridge University Press

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Eckstein, E. C. 1975 Particle migration in a linear shear flow. Ph.D. thesis, Massachusetts Institute of Technology.
Eckstein, E. C., Bailey, D. G. & Shapiro, A. H. 1977 Self-diffusion of particles in shear flow of a suspension. J. Fluid Mech. 79, 191.Google Scholar
Frankel, N. A. & Acrivos, A. 1968 Heat and mass transfer from small spheres and cylinders freely suspended in shear flow. Phys. Fluids 11, 1913.Google Scholar
Graham, A. L. & Bird, R. B. 1984 Particle clusters in concentrated suspensions. 1. Experimental observations of particle clusters. Ind. Engng Chem. Fundam. 23, 406.Google Scholar
Graham, A. L. & Steele, R. D. 1984 Particle clusters in concentrated suspensions. 2. Information theory and particle clusters. Ind. Engng Chem. Fundam. 23, 411.Google Scholar
Karnis, A., Goldsmith, H. L. & Mason, S. G. 1966 The kinetics of flowing dispersions. I. Concentrated suspensions of rigid particles. J. Colloid Interface Sci. 22, 531.Google Scholar
Leighton, D. & Acrivos, A. 1986 The shear induced migration of particles in concentrated suspensions. J. Fluid Mech. (submitted).Google Scholar
Okagawa, A., Ennis, G. J. & Mason, S. G. 1978 Memory impairment in flowing suspensions. I. Some theoretical considerations. Can. J. Chem. 56, 2815.Google Scholar