Vesicle migration and spatial organization driven by flow line curvature.

Cross-streamline migration of deformable entities is essential in many problems such as industrial particulate flows, DNA sorting, and blood rheology. Using two-dimensional numerical experiments, we have discovered that vesicles suspended in a flow with curved flow lines migrate towards regions of high flowline curvature, which are regions of high shear rates. The migration velocity of a vesicle is found to be a universal function of the normal stress difference and the flow curvature. This finding quantitatively demonstrates a direct coupling between a microscopic quantity (migration) and a macroscopic one (normal stress difference). Furthermore, simulations with multiple vesicles revealed a self-organization, which corresponds to segregation, in a rim closer to the inner cylinder, resulting from a subtle interaction among vesicles. Such segregation effects could have a significant impact on the rheology of vesicle flows.

Citation

Giovanni Ghigliotti, Abtin Rahimian, George Biros, Chaouqi Misbah. Vesicle migration and spatial organization driven by flow line curvature. Physical review letters. 2011 Jan 14;106(2):028101

Mesh Tags

PMID: 21405252

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