Capillary Flows of Suspensions

Interfacial flows of multiphase systems containing a dispersed solid phase occur in a broad range of environmental, manufacturing, and bioengineering processes. However, classical interfacial dynamics is strongly modified when the liquid thickness becomes comparable to the particle size. This configuration can cause classical rheological models to fail. Particles may destabilize thin films, create defects in additive manufacturing, reduce transport efficiency, and contaminate substrates.

The talk presents recent studies that clarify how interfaces govern suspension dynamics in complex environments. Capillary displacement of a suspension in confinement leads to distinct regimes in which particles either deposit on walls or remain in the flow. These observations suggest passive capillary filtering and sorting strategies. The second part describes how particles modify droplet formation and the atomization of suspension sheets and ligaments.

Our approach, which bridges different length and timescales, describes how bulk behavior and local heterogeneities contribute to the dynamics of multiphase capillary objects.