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Shear-induced dispersion in a dilute suspension of rough spheres

Published online by Cambridge University Press:  26 April 2006

F. R. Da Cunha
Affiliation:
Department of Applied Mathematics and Theoretical Physics, The University of Cambridge, Silver Street, Cambridge CB3 9EW, UK Current address: University of Brazilia, Department of Mechanical Engineering, Campus Universitario-Asa Norte, Brasilia-DF, Brazil 70910-900.
E. J. Hinch
Affiliation:
Department of Applied Mathematics and Theoretical Physics, The University of Cambridge, Silver Street, Cambridge CB3 9EW, UK

Abstract

In the absence of Brownian motion, inertia and inter-particle forces, two smooth spheres collide in a simple shear flow in a reversible way returning to their initial streamlines. Because the minimum separation during the collision can be less than 10−4 of the radius, quite a small surface roughness can have a significant irreversible effect on the collision. We calculate the change between the initial and final streamlines caused by roughness. Repeated random collisions in a dilute suspension lead to a diffusion of the particles across the streamlines. We calculate the shear-induced diffusivity for both self-diffusion and down-gradient diffusion.

Type
Research Article
Copyright
© 1996 Cambridge University Press

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