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Updated: Mar 26, 2026

The Diffusion of Passive Tracers in Laminar Shear Flow
Published on: May 1, 2018
Biased transport of Brownian particles in a weakly corrugated serpentine channel
1Division of Mathematics and Computer Science, University of South Carolina Upstate, 800 University Way, Spartanburg, South Carolina 29303, USA.
Abstract:
We investigate the biased transport of Brownian particles in a weakly corrugated channel with constant width but a varying centerline (called serpentine channel). Two different types of channels are considered: a soft-channel is confined by a potential energy landscape; a solid-channel is confined by solid walls. Based on the small amplitude of channel boundaries, the asymptotic method is used to analytically calculate two important macroscopic transport properties--average velocity (or mobility) and effective dispersion coefficient. We find the nonlinear dependence of transport properties on Péclet numbers, which is qualitatively different from the results in a narrow serpentine channel, in which the leading order terms of mobility and the effective dispersion coefficient do not depend on Péclet numbers. In the purely diffusive case where the Péclet number is zero, the Sutherland-Einstein relation is satisfied in both soft and solid channels.
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