Hydrodynamics of double emulsion droplet in shear flow

Hydrodynamic behaviors of double emulsion droplets in shear flow, both deformation and breakup, are investigated numerically. We find that the inner drop is deformed in a uniform vortical flow interior to the outer drop under steady state deformation conditions and provides an additional deformation resistance for the integral droplet especially when its volume fraction is large. In particular, we report four types of breakup modes via three mechanisms (i.e., necking, end pinching, and capillary instability), respectively, and present the corresponding phase diagrams to describe the breakup criteria (critical capillary numbers) and morphologies. (C) 2013 American Institute of Physics. [http://dx.doi.org/10.1063/1.4789865]