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Updated: Jun 14, 2026
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Microtensiometer for Confocal Microscopy Visualization of Dynamic Interfaces
Published on: September 9, 2022
Nonequilibrium fluctuations of an interface under shear
Marine Thiébaud1, Thomas Bickel
1CPMOH, Université de Bordeaux and CNRS (UMR 5798), 351 Cours de la Libération, 33405 Talence, France.
Summary
Thermal fluctuations in Couette flow are driven out of equilibrium by an effective shear rate. This nonequilibrium behavior, characterized by a single control parameter, reduces interface mean-square displacement, aligning with experimental findings.
Area of Science:
- Fluid dynamics
- Statistical mechanics
- Interface phenomena
Background:
- Understanding the behavior of interfaces in fluid flow is crucial for various scientific and engineering applications.
- Stationary Couette flow provides a well-defined system to study shear-driven phenomena.
- Fluctuating hydrodynamics offers a theoretical framework to incorporate thermal fluctuations.
Purpose of the Study:
- To investigate the steady-state properties of an interface in a stationary Couette flow.
- To analyze the impact of thermal fluctuations on interface dynamics under shear.
- To explore the universality of nonequilibrium fluctuations in this system.
Main Methods:
- Application of fluctuating hydrodynamics theory.
- Analysis of steady-state properties of an interface.
- Derivation of an effective shear rate for thermal fluctuations.
Main Results:
- Thermal fluctuations are driven out of equilibrium by an effective shear rate distinct from the applied shear rate.
- The mean-square displacement of the interface is reduced by the flow, consistent with experimental observations.
- Nonequilibrium fluctuations exhibit universality, reducible to a single control parameter.
Conclusions:
- The study provides a theoretical explanation for the observed reduction in interface displacement under shear flow.
- The concept of an effective shear rate offers new insights into nonequilibrium phenomena.
- The identified universality suggests broader applicability of the findings to similar fluid systems.
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