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An Analog Macroscopic Technique for Studying Molecular Hydrodynamic Processes in Dense Gases and Liquids
Published on: December 4, 2017
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Brownian Particle Thermal Drift Caused by Hydrodynamic Fluctuations
Konstantin I Morozov1, Werner Köhler2
1Department of Chemical Engineering, Technion-Israel Institute of Technology, Haifa 32000, Israel.
The Journal of Physical Chemistry. B
|July 2, 2021
Summary
We studied Brownian particle thermophoresis using fluctuating hydrodynamics. A new formula for drift velocity was derived, accounting for viscosity changes and validated with experiments.
Area of Science:
- Physics
- Physical Chemistry
Background:
- Brownian motion describes random particle movement in fluids.
- Thermophoresis is particle movement due to temperature gradients.
- Fluctuating hydrodynamics models fluid behavior with inherent fluctuations.
Purpose of the Study:
- To investigate the thermophoretic drift of a Brownian particle.
- To apply the Landau-Lifshitz fluctuating hydrodynamics theory.
- To derive an analytical expression for drift velocity.
Main Methods:
- Utilized the theory of fluctuating hydrodynamics.
- Analyzed the stochastic motion of a dispersed particle.
- Incorporated temperature-dependent viscosity effects on fluid stress tensor fluctuations.
Main Results:
- Derived an analytical expression for the thermophoretic drift velocity.
- Identified that non-vanishing quadratic fluctuation terms contribute to mean volume force.
- Demonstrated the influence of temperature-dependent viscosity.
Conclusions:
- The study provides a theoretical framework for understanding Brownian particle thermophoresis.
- The derived analytical expression offers a quantitative prediction of drift velocity.
- Experimental validation confirmed the theoretical predictions, highlighting the importance of viscosity effects.
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