Fluid Vesicles in Shear Flow

TL;DR

This paper introduces a numerical method to analyze the shape and orientation dynamics of fluid vesicles in shear flow, revealing how their behavior depends on shear rate and volume through simulations and simplified models.

Contribution

A novel numerical scheme using the Oseen tensor formalism for simulating arbitrarily shaped vesicles in shear flow, providing insights into their stationary shapes and orientation behavior.

Findings

Stationary vesicle shapes depend on shear rate and volume.

Vesicle orientation varies systematically with shear conditions.

Simplified models can explain key aspects of vesicle dynamics.

Abstract

The shape dynamics of fluid vesicles is governed by the coupling of the flow within the two-dimensional membrane to the hydrodynamics of the surrounding bulk fluid. We present a numerical scheme which is capable of solving this flow problem for arbitrarily shaped vesicles using the Oseen tensor formalism. For the particular problem of simple shear flow, stationary shapes are found for a large range of parameters. The dependence of the orientation of the vesicle and the membrane velocity on shear rate and vesicle volume can be understood from a simplified model.