Dynamics and rheology of periodically driven suspensions

Suspensions of hydrodynamically interacting particles are important model systems for a range of natural and industrial problems, such as protein transport in tissues or rational design of novel metamaterials, thus understanding their dynamics and rheology is of key importance. Most natural and industrial flows are time-dependent; so, it is particularly relevant to examine the suspension behaviour when it is driven periodically. Recent work in the literature have identified two mechanisms for non-colloidal suspensions of spherical particles to undergo reversible-irreversible transitions in oscillatory shear, due to either interparticle collision or attraction. However, none of the studies has included long-range hydrodynamic interactions, which may be crucial to the transient dynamics of the system. Here, we numerically examine the suspension dynamics and rheology with full hydrodynamic interactions using a newly developed fast Stokesian dynamics method. The effect of particle geometry, modelled from rigidly connecting spherical beads into composites, will also be discussed.