Motion of rigid aggregates under different flow conditions

The response of rigid aggregates to different flow fields was investigated theoretically using model clusters with realistic three-dimensional structure composed of identical spherical primary particles. The aim is to relate the main fluid dynamic properties of the system with the geometry and morphology of the aggregates. Our simulations were based on Stokesian dynamics. The dilute limit of a colloidal aggregate system was studied, where aggregates are very far from each other and hence mutual interaggregate interactions are negligible. The motion of aggregates was characterized in terms of translational mobility and angular velocity, and the ability of simple models, based on either simplified aggregate geometry or the concept of permeability, to capture the main features of the motion was examined.