Abstract
A shear flow of particulate suspension is analyzed for the qualitative effect of particle clustering on viscosity using a simple kinetic clustering model and direct numerical simulations. The clusters formed in a Couette flow can be divided into rotating chainlike clusters and layers of particles at the channel walls. The size distribution of the rotating clusters is scale invariant in the small-cluster regime and decreases rapidly above a characteristic length scale that diverges at a jamming transition. The behavior of the suspension can qualitatively be divided into three regimes. For particle Reynolds number Rep≲0.1, viscosity is controlled by the characteristic cluster size deduced from the kinetic clustering model. For
Rep∼1, clustering is maximal, but the simple kinetic model becomes inapplicable presumably due to onset of instabilities. In this transition regime viscosity begins to increase. For Rep≳10, inertial effects become important, clusters begin to breakup, and suspension displays shear thickening. This phenomenon may be attributed to enhanced contribution of solid phase in the total shear stress.
Rep∼1, clustering is maximal, but the simple kinetic model becomes inapplicable presumably due to onset of instabilities. In this transition regime viscosity begins to increase. For Rep≳10, inertial effects become important, clusters begin to breakup, and suspension displays shear thickening. This phenomenon may be attributed to enhanced contribution of solid phase in the total shear stress.
Original language | English |
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Article number | 061403 |
Number of pages | 3 |
Journal | Physical Review E: Statistical, Nonlinear, and Soft Matter Physics |
Volume | 68 |
Issue number | 6 |
DOIs | |
Publication status | Published - 2003 |
MoE publication type | A1 Journal article-refereed |
Keywords
- flow shear
- shear
- shear properties
- suspensions
- viscosity