Title: From microstructure to bulk stress in concentrated suspensions

Author (Invited): Jeff Morris, Levich Institute, CCNY

Abstract:

It is well-known that the bulk stress of a suspension of solid particles in a liquid, whether colloidal or noncolloidal, depends strongly upon the solid fraction. Considering particles suspended in Newtonian liquids, the resulting mixture is generally non-Newtonian, but it is not precisely understood what form the stress should take. This is a problem which is intimately related to the microstructure of the material. Understanding gained from microstructural theoretical analysis and simulation will be used to motivate the general form of the suspension stress constitutive behavior. We will focus upon the normal stress response of these materials, showing that the response includes not only noraml stress differences, but also a dispersive isotropic component which is of particular interest to describing bulk migration phenomena and diffusion.