Abstract
Rheology and microstructure of plate-like particle suspensions in linear shear flows are studied through Stokesian dynamics simulations with Brownian motion for a range of volume fraction φ up to 0.30 and Peclet number Pe ranging from 0.01 to 104. As in Part I [Meng and Higdon, J. Rheol. 52, 1 (2008)], particles are modeled as planar assemblages of spheres. The effects of Brownian motion on the suspensions microstructure are studied with special attention to two ordering mechanisms observed for non-Brownian systems: (1) the formation of sliding planes of aligned layers of particles and (2) the formation of transient stacks of plate-like particles which move as rigid assemblies. At low Pe, strong Brownian motion yields random particle orientations, however the aligned particle layers are recovered at Pe as low as 0.1 for low φ and 0.4 for φ=0.30. Brownian motion acts more effectively in disrupting particle stacks with measurable reduction in stack formation up to Pe of 1000. The plate-like particle suspensions exhibit both shear thinning and shear thickening behavior as a function of Pe, however, the Pe dependence differs from that for suspensions of spheres. The effect of Brownian motion on particle alignment introduces an additional factor enhancing shear thinning, and the shear thickening is weaker than for suspensions of spheres.
Original language | English (US) |
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Pages (from-to) | 37-65 |
Number of pages | 29 |
Journal | Journal of Rheology |
Volume | 52 |
Issue number | 1 |
DOIs | |
State | Published - 2008 |
Keywords
- Brownian dynamics
- Microstructure
- Ordering
- Plate-like particles
- Stokesian dynamics
- Suspension rheology
ASJC Scopus subject areas
- General Materials Science
- Condensed Matter Physics
- Mechanics of Materials
- Mechanical Engineering