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Dynamics and rheology of a dilute suspension of vesicles: higher order theory

Gerrit Danker·Thierry Biben·Thomas Podgorski·Claude Verdier·Chaouqi Misbah
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Abstract

Vesicles under shear flow exhibit various dynamics: tank-treading ($tt$), tumbling ($tb$) and vacillating-breathing ($vb$). A consistent higher order theory reveals a direct bifurcation from $tt$ to $tb$ if $C_a\equiv τ\dotγ$ is small enough ($τ$= vesicle relaxation time towards equilibrium shape, $\dotγ$=shear rate). At larger $C_a$ the $tb$ is preceded by the $vb$ mode. For $C_a\gg 1$ we recover the leading order original calculation, where the $vb$ mode coexists with $tb$. The consistent calculation reveals several quantitative discrepancies with recent works, and points to new features. We analyse rheology and find that the effective viscosity exhibits a minimum at $tt-tb$ and $tt-vb$ bifurcation points.

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Gerrit Danker, Thierry Biben, Thomas Podgorski, Claude Verdier, Chaouqi Misbah. 2007-07-14. Dynamics and rheology of a dilute suspension of vesicles: higher order theory. https://doi.org/10.1103/physreve.76.041905

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