Unifying disparate rate-dependent rheological regimes in non-Brownian suspensions

A typical dense non-Brownian particulate suspension exhibits shear thinning (decreasing viscosity) at low rate or stress followed by a Newtonian plateau (constant intermediate values which transitions to thickening (increasing beyond critical value and finally undergoes second transition extremely high values. In this study, we unify quantitatively reproduce all the disparate rate-dependent regimes corresponding for with increasing stress. We employ discrete particle dynamics simulations based on proposed mechanism elucidate its accuracy. find that competition between interparticle interactions of hydrodynamic nonhydrodynamic origins switching in dominant scale lead each above transitions. Inclusion traditional interactions, attractive repulsive Derjaguin-Landau-Verwey-Overbeek (DLVO) contact constant friction (or other constraint mechanism) reproduces initial as well transition. However, capture thinning, an additional interaction non-DLVO origin decreasing coefficient friction, respectively, are essential, thus providing explanation presence along reproducing single framework. Expressions utilized various determined from experimental measurements hence result excellent quantitative agreement previous experiments.