Flow of a highly-concentrated emulsion through a narrow constriction

Multipole-accelerated boundary-integral algorithm is developed to study creeping flow of an emulsion of many (N>100) deformable 3D drops with high volume fraction (80-90%) though a microchannel with tight constriction. The simulation setup is designed to resemble the experiments [1]; the channel depth and throat width are comparable to the drop non-deformed size and are an order of magnitude smaller than the entrance width, so that the emulsion flow away from the throat is rearranged into a single file motion in the constriction. Periodic inlet/outlet boundaries with prescribed pressure drop are used to formulate boundary-integral equations based on the 1-periodic Green function. Multipole acceleration tools [2] allow for necessary ultra-high resolution on the drop surfaces and channel walls to study the statistics of drop rearrangement/breakup at the constriction, critical breakup conditions and the dependence of flow rate on the capillary number and channel geometry.

[1] L. Rosenfeld et. al. Break-up of droplets in a concentrated emulsion flowing through a narrow constriction. Soft Matter, 2014, 10, 421-430.

[2] A.Z. Zinchenko & R.H. Davis. Emulsion flow through a packed bed with multiple drop breakup. J. Fluid Mech., 2013, 725, 611-663.