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arXiv · 1506.09041

A unified description of the rheology of hard-particle suspensions

B. M. Guy·M. Hermes·W. C. K. Poon
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Abstract

The rheology of suspensions of Brownian, or colloidal, particles (diameter $d \lesssim 1$ $μ$m) differs markedly from that of larger grains ($d \gtrsim 50$ $μ$m). Each of these two regimes has been separately studied, but the flow of suspensions with intermediate particle sizes (1 $μ\textrm{m} \lesssim d \lesssim 50$ $μ$m), which occur ubiquitously in applications, remains poorly understood. By measuring the rheology of suspensions of hard spheres with a wide range of sizes, we show experimentally that shear thickening drives the transition from colloidal to granular flow across the intermediate size regime. This insight makes possible a unified description of the (non-inertial) rheology of hard spheres over the full size spectrum. Moreover, we are able to test a new theory of friction-induced shear thickening, showing that our data can be well fitted using expressions derived from it.

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B. M. Guy, M. Hermes, W. C. K. Poon. 2015-08-24. A unified description of the rheology of hard-particle suspensions. https://doi.org/10.1103/physrevlett.115.088304

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