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

✍ Scribed by Leighton, David (author);Acrivos, Andreas (author)

• Book ID: 120108072
• Publisher: Cambridge University Press
• Year: 1987
• Tongue: English
• Weight: 440 KB
• Volume: 177
• Category: Article
• ISSN: 0022-1120
• DOI: 10.1017/S0022112087000880

✦ Synopsis

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.