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Bibliographic Details
Main Author: Manikantan, Harishankar
Format: Preprint
Published: 2024
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Online Access:https://arxiv.org/abs/2402.15148
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author Manikantan, Harishankar
author_facet Manikantan, Harishankar
contents We develop a mean-field model to examine the stability of a `quasi-2D suspension' of elongated particles embedded within a viscous membrane. This geometry represents several biological and synthetic settings, and we reveal mechanisms by which the anisotropic mobility of particles interacts with long-ranged viscous membrane hydrodynamics. We first show that a system of slender rod-like particles driven by a constant force is unstable to perturbations in concentration -- much like sedimentation in analogous 3D suspensions -- so long as membrane viscous stresses dominate. However, increasing the contribution of viscous stresses from the surrounding 3D fluid(s) suppresses such an instability. We then tie this result to the hydrodynamic disturbances generated by each particle in the plane of the membrane and show that enhancing subphase viscous contributions generates extensional fields that orient neighboring particles in a manner that draws them apart. The balance of flux of particles aggregating versus separating then leads to a wave number selection in the mean-field model.
format Preprint
id arxiv_https___arxiv_org_abs_2402_15148
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Stability of a dispersion of elongated particles embedded in a viscous membrane
Manikantan, Harishankar
Fluid Dynamics
Soft Condensed Matter
We develop a mean-field model to examine the stability of a `quasi-2D suspension' of elongated particles embedded within a viscous membrane. This geometry represents several biological and synthetic settings, and we reveal mechanisms by which the anisotropic mobility of particles interacts with long-ranged viscous membrane hydrodynamics. We first show that a system of slender rod-like particles driven by a constant force is unstable to perturbations in concentration -- much like sedimentation in analogous 3D suspensions -- so long as membrane viscous stresses dominate. However, increasing the contribution of viscous stresses from the surrounding 3D fluid(s) suppresses such an instability. We then tie this result to the hydrodynamic disturbances generated by each particle in the plane of the membrane and show that enhancing subphase viscous contributions generates extensional fields that orient neighboring particles in a manner that draws them apart. The balance of flux of particles aggregating versus separating then leads to a wave number selection in the mean-field model.
title Stability of a dispersion of elongated particles embedded in a viscous membrane
topic Fluid Dynamics
Soft Condensed Matter
url https://arxiv.org/abs/2402.15148