Swirling and snaking, 3D oscillatory bifurcations of vesicle dynamics in microcirculation

TL;DR

This paper presents a comprehensive phase diagram of 3D vesicle dynamics in microcirculation, revealing new oscillatory behaviors such as swirling and snaking, and analyzing their bifurcation mechanisms.

Contribution

It introduces two novel oscillatory vesicle behaviors, swirling and snaking, in 3D flow, expanding understanding of vesicle dynamics beyond stationary shapes.

Findings

Identified 3D snaking and swirling as new oscillatory dynamics.

Swirling arises from a supercritical pitchfork bifurcation.

Swirling coexists with slipper shape in certain conditions.

Abstract

Vesicles are soft elastic bodies with distinctive mechanical properties such as bending resistance, membrane fluidity, and their strong ability to deform, mimicking some properties of biological cells. While previous three-dimensional (3D) studies have identified stationary shapes such as slipper and axisymmetric ones, we report a complete phase diagram of 3D vesicle dynamics in a bounded Poiseuille flow with two more oscillatory dynamics, 3D snaking and swirling. 3D snaking is characterized by planar oscillatory motion of the mass center and shape deformations, which is unstable and leads to swirling or slipper. Swirling emerges from supercritical pitchfork bifurcation. The mass center moves along a helix, the preserved shape rolls on itself and spins around the flow direction. Swirling can coexist with slipper.