Modeling the effects of polydispersity on the viscosity of noncolloidal hard sphere suspensions
Date
2016-01-14
Journal Title
Journal ISSN
Volume Title
Publisher
The Society of Rheology
Abstract
The present study develops an extension of the approach pioneered by Farris [Trans. Soc. Rheol. 12, 281–301 (1968)] to model the viscosity
in polydisperse suspensions. Each smaller particle size class is assumed to contribute to the suspension viscosity through a weighting
function in two ways: first, indirectly, by altering the background viscosity, and second, directly, by increasing the contribution of the larger
particles to the suspension viscosity. The weighting functions are developed in a consistent fashion as a power law with the exponent, h, a
function of the relative volume fraction ratio and the base, g, a function of the solid particle size ratio. The model is fit to available
theoretical and experimental results for the viscosity of several binary suspensions and shows good to excellent agreement depending on the
functions g and h chosen. Once parameterized using binary suspension viscosity data, the predictive capability to model the viscosity of
arbitrary continuous size distributions is realized by representing such distributions with equivalent ternary approximations selected to match
the first six moments of the actual size distribution. Model predictions of the viscosity of polydisperse suspensions are presented and
compared against experimental data.
Description
Publisher's PDF
Keywords
Citation
Journal of Rheology 60, 225 (2016); doi: 10.1122/1.4938048.