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Updated: Oct 30, 2025

An Analog Macroscopic Technique for Studying Molecular Hydrodynamic Processes in Dense Gases and Liquids
Published on: December 4, 2017
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.
Abstract:
We have studied the thermophoretic drift of a Brownian particle within the framework of the theory of fluctuating hydrodynamics of Landau and Lifshitz. The stochastic motion of a dispersed particle results from the fluctuating part of the stress tensor of the liquid. In the presence of a temperature gradient, the mean volume force acting on the liquid assumes a finite value due to non-vanishing quadratic terms in the fluctuations, which originate from the temperature dependence of the viscosity. An analytical expression is derived for the drift velocity and compared to experimental results.
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