We introduce a class of simple models for shear thickening and/or ‘‘jamming’’ in colloidal suspensions. These are based on the schematic mode coupling theory ~MCT! of the glass transition, having a memory term that depends on a density variable, and on both the shear stress and the shear rate. ~Tensorial aspects of the rheology, such as normal stresses, are ignored for simplicity.! We calculate...

We propose a unifying rheological framework for dense suspensions of non-Brownian spheres, predicting the onsets of particle friction and particle inertia as distinct shear thickening mechanisms, while capturing quasistatic and soft particle rheology at high volume fractions and shear rates respectively. Discrete element method simulations that take suitable account of hydrodynamic and particle...

Colloidal suspensions exhibit shear thinning and shear thickening. The most common interpretation of these phenomena identifies layering of the fluid perpendicular to the shear gradient as the driver for the observed behavior. However, studies of the particle configurations associated with shear thinning and thickening cast doubt on that conclusion and leave unsettled whether these nonequilibri...

Viscoelastic fluids exhibit rheological nonlinearity at a high shear rate. Although typical nonlinear effects, shear thinning and shear thickening, have been usually understood by variation of intrinsic quantities such as viscosity, one still requires a better understanding of the microscopic origins, currently under debate, especially on the shear-thickening mechanism. We present accurate meas...

Shear thickening appears as an increase of the viscosity of a dense suspension with the shear rate, sometimes sudden and violent at high volume fraction. Its origin for noncolloidal suspension with non-negligible inertial effects is still debated. Here we consider a simple shear flow and demonstrate that fluid inertia causes a strong microstructure anisotropy that results in the formation of a ...

– A new mechanism is suggested for shear thickening in dilute solutions of wormlike micelles. According to this mechanism, there is an instability above a critical shear rate, γ̇c, by which micelles aggregate to form networks of bundles. We examine the first step of this instability by studying the aggregation of two micelles into a paired bundle. The model predicts that γ̇c is given by the inver...

The laminar flow of a number of fluids such as polymeric liquids, food products, paints, slurries, foams, and so forth cannot be adequately described by the help of the classical linearly viscous Newtonian model. Thus, there is a need to have at hand an arsenal of non-Newtonian fluid models and over the past several decades a variety of models have been developed. While the fluids of the differ...

Cylindrical cavitation bubbles, capable of generating extreme strain rates, are experimentally and theoretically studied in shear-thickening suspensions. Starting from the limit between continuous discontinuous shear thickening regimes, bubbles deform increasingly with increasing solid volume fraction until replaced by cavitation-induced fractures.

Recent studies of athermal systems such as dry grains and dense, non-Brownian suspensions have shown that shear can lead to solidification through the process of shear jamming in grains and discontinuous shear thickening in suspensions. The similarities observed between these two distinct phenomena suggest that the physical processes leading to shear-induced rigidity in athermal materials are u...