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Updated: May 16, 2026

The Diffusion of Passive Tracers in Laminar Shear Flow
Published on: May 1, 2018
Diffusion in two-dimensional conical varying width channels: comparison of analytical and numerical results
Inti Pineda1, José Alvarez-Ramirez, Leonardo Dagdug
1Basic Sciences and Engineering, Universidad Autónoma Metropolitana, Apartado Postal 55-534, Mexico DF 09340, Mexico.
Abstract:
This study is devoted to the unbiased motion of a point-like brownian particle in two-dimensional tilted asymmetric channels of varying width formed by straight walls. An effective one-dimensional description in terms of the generalized Fick-Jacobs equation is used to derive formulas that yield the particle's effective diffusion coefficient as a function of the geometric parameters of the channel. To such end, we use the formulas obtained by Bradley [Phys. Rev. E 80, 061142 (2009)] and by Dagdug and Pineda [J. Chem. Phys. 137, 024107 (2012)] to study two-dimensional diffusion in narrow and smoothly asymmetric channels of varying width. Comparison with brownian dynamics simulation results allows us to establish the domain of applicability of both the one-dimensional description and the effective diffusion coefficient formulas.
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