Role of surfactant-induced Marangoni stresses in drop-interface coalescence
File(s)
Accepted version
Author(s)
Type
Journal Article
Abstract
We study the effect of surfactants on the dynamics of a drop-interface coalescence using full three-dimensional direct numerical simulations. We employ a hybrid interface-tracking/level-set method, which takes into account Marangoni stresses that arise from surface-tension gradients, interfacial and bulk diffusion and sorption kinetic effects. We validate our predictions against the experimental data of Blanchette and Bigioni (Nat. Phys., vol. 2, issue 4, 2006, pp. 254–257) and perform a parametric study that demonstrates the delicate interplay between the flow fields and those associated with the surfactant bulk and interfacial concentrations. The results of this work unravel the crucial role of the Marangoni stresses in the flow physics of coalescence, with particular attention paid to their influence on the neck reopening dynamics in terms of stagnation-point inhibition, and near-neck vorticity generation. We demonstrate that surfactant-laden cases feature a rigidifying effect on the interface compared with the surfactant-free case, a mechanism that underpins the observed surfactant-induced phenomena.
Date Issued
2021-10-25
Date Acceptance
2021-08-01
Citation
Journal of Fluid Mechanics, 2021, 925, pp.1-21
ISSN
0022-1120
Publisher
Cambridge University Press (CUP)
Start Page
1
End Page
21
Journal / Book Title
Journal of Fluid Mechanics
Volume
925
Copyright Statement
© The Author(s), 2021. Published by Cambridge University Press. This article has been published in a revised form in Journal of Fluid Mechanics https://doi.org/10.1017/jfm.2021.682. This version is free to view and download for private research and study only. Not for re-distribution, re-sale or use in derivative works.
Sponsor
Engineering & Physical Science Research Council (EPSRC)
Engineering & Physical Science Research Council (EPSRC)
Engineering & Physical Science Research Council (E
Identifier
https://www.cambridge.org/core/journals/journal-of-fluid-mechanics/article/role-of-surfactantinduced-marangoni-stresses-in-dropinterface-coalescence/A0E3D856050B37F5C7C30F047ED03774
Grant Number
EP/K003976/1
EP/T000414/1
EP/V502354/1
Subjects
Fluids & Plasmas
01 Mathematical Sciences
09 Engineering
Publication Status
Published
Article Number
A15
Date Publish Online
2021-08-23