Spontaneous onset of convection in a uniform phoretic channel.
File(s)1912.07667v1.pdf (4.36 MB)
Accepted version
Author(s)
Michelin, S
Game, S
Lauga, E
Keaveny, E
Papageorgiou, D
Type
Journal Article
Abstract
Phoretic mechanisms, whereby gradients of chemical solutes induce surface-driven flows, have recently been used to generate directed propulsion of patterned colloidal particles. When the chemical solutes diffuse slowly, an instability further provides active isotropic particles with a route to self-propulsion by spontaneously breaking the symmetry of the solute distribution. Here we show theoretically that, in a mechanism analogous to Bénard-Marangoni convection, phoretic phenomena can create spontaneous and self-sustained wall-driven mixing flows within a straight, chemically-uniform active channel. Such spontaneous flows do not result in any net pumping for a uniform channel but greatly modify the distribution and transport of the chemical solute. The instability is predicted to occur for a solute Péclet number above a critical value and for a band of finite perturbation wavenumbers. We solve the perturbation problem analytically to characterize the instability, and use both steady and unsteady numerical computations of the full nonlinear transport problem to capture the long-time coupled dynamics of the solute and flow within the channel.
Date Issued
2020-02-07
Date Acceptance
2019-12-16
ISSN
1744-683X
Publisher
Royal Society of Chemistry
Start Page
1259
End Page
1269
Journal / Book Title
Soft Matter
Volume
16
Issue
5
Copyright Statement
© The Royal Society of Chemistry 2020
Identifier
https://pubs.rsc.org/en/content/articlelanding/2020/SM/C9SM02173F#!divAbstract
https://www.ncbi.nlm.nih.gov/pubmed/31913392
Subjects
physics.flu-dyn
physics.flu-dyn
cond-mat.soft
physics.bio-ph
02 Physical Sciences
03 Chemical Sciences
09 Engineering
Chemical Physics
Publication Status
Published
Coverage Spatial
England
Date Publish Online
2019-12-16