Dynamics and Rheology of Vesicle Suspensions in Wall-Bounded Shear Flow

TL;DR

This study investigates the behavior and rheological properties of vesicle suspensions under wall-bounded shear flow using combined molecular dynamics and mesoscale simulations, revealing how flow conditions influence vesicle interactions and suspension viscosity.

Contribution

It introduces a simulation approach to analyze vesicle suspension dynamics and rheology in confined shear flow, highlighting the effects of shear rate, volume fraction, and viscosity contrast.

Findings

Vesicle interactions depend on shear rate and volume fraction.

Intrinsic viscosity varies with flow conditions.

A cell-free layer forms near the walls.

Abstract

The dynamics and rheology of suspensions of fluid vesicles or red blood cells is investigated by a combination of molecular dynamics and mesoscale hydrodynamics simulations in two dimensions. The vesicle suspension is confined between two no-slip walls, which are driven externally to generate a shear flow with shear rate $\dot\gamma$. The flow behavior is studied as a function of $\dot\gamma$, the volume fraction of vesicles, and the viscosity contrast between inside and outside fluids. Results are obtained for the encounter and interactions of two vesicles, the intrinsic viscosity of the suspension, and the cell-free layer near the walls.