arrow
Return

A diffuse-interface Marangoni instability

delete2025-12-04
delete0
delete
OA
AI
X
Xiangwei Li
D
Dongdong Wan
H
Haohao Hao
C
Christian Diddens
M
Mengqi Zhang
谭唤书 cover
谭唤书 (Huanshu Tan) *
DOI:10.1017/jfm.2025.10895delete
deleteOriginal
deleteShare
deleteSave
View PDF
Abstract

Abstract

En 中文
We investigate a novel Marangoni-induced instability that arises exclusively in diffuse fluid interfaces, that is absent in classical sharp-interface models. Using a validated phase-field Navier-Stokes-Allen-Cahn framework, we linearise the governing equations to analyse the onset and development of interfacial instability driven by solute-induced surface tension gradients. A critical interfacial thickness scaling inversely with the Marangoni number, $\delta _{\textit{cr}} \sim \textit{Ma}<^>{-1}$ , emerges from the balance between advective and diffusive transport. Unlike sharp-interface scenarios where matched viscosity and diffusivity stabilise the interface, finite thickness induces asymmetric solute distributions and tangential velocity shifts that destabilise the system. We identify universal power-law scalings of velocity and concentration offsets with a modified Marangoni number $\textit{Ma}_\delta$ , independent of capillary number and interfacial mobility. A critical crossover at $ \textit{Ma}_\delta \approx 590$ distinguishes diffusion-dominated stabilisation from advection-driven destabilisation. These findings highlight the importance of diffuse-interface effects in multiphase flows, with implications for miscible fluids, soft matter, and microfluidics where interfacial thickness and coupled transport phenomena are non-negligible.
Keywords:
Marangoni convection
interfacial flows (free surface)
instability
AI Summary

AI Summary

Key information extracted from the uploaded paper, including a brief overview, abstract, background, key highlights, visual analysis, and future outlook.

Journal

Journal of Fluid Mechanics cover
Journal of Fluid Mechanics
IF:
3.9
Papers:
2.0W
Citations:
9.4W

Organization

U
university of twente
Scholars:
1.5W
Papers: 1.4W
Citations: 9
N
national university of singapore
Scholars:
4.6K
Papers: 2.4K
Citations: 1