Rheology of sedimenting particle pastes

Abdoulaye Fall (1, 2) , Henri de Cagny (3) , Daniel Bonn (3, 4) , Guillaume Ovarlez (5) , Elie Wandersman (6, 7) , Joshua Dijksman (7) , Martin van Hecke (7)

1 navier umr 8205 - Laboratoire Navier
2 van der Waals-Zeeman Institue
3 van der Waals-Zeeman Institute
4 LPS - Laboratoire de Physique Statistique de l'ENS
5 Rhéophysique
6 Laboratoire Jean PERRIN
7 Kamerlingh Onnes Lab

We study the local and global rheology of non-Brownian suspensions in a solvent that is not density-matched, leading to either creaming or sedimentation of the particles. Both local and global measurements show that the incomplete density matching leads to the appearance of a critical shear rate above which the suspension is homogenized by the flow, and below which sedimentation or creaming happens. We show that the value of the critical shear rate and its dependence on the experimental parameters are governed by a competition between the viscous and the gravitational forces, and present a simple scaling model that agrees with the experimental results from different types of experiments (local and global) in different setups and systems.

Mots clés: DENSE GRANULAR FLOWS; NONCOLLOIDAL PARTICLES; CONSTITUTIVE LAW; FLUID-MECHANICS; YIELD STRESSES; SUSPENSIONS

Domaines: Matière Molle [cond-mat.soft]

Abdoulaye Fall, Henri de Cagny, Daniel Bonn, Guillaume Ovarlez, Elie Wandersman, et al.. Rheology of sedimenting particle pastes. Journal of Rheology, 2013, 57 (4), pp.1237-1246. ⟨10.1122/1.4809732⟩. ⟨hal-00925901⟩