Geometry controlled dispersion in periodic corrugated channels
Language
en
Article de revue
This item was published in
EPL - Europhysics Letters. 2017, vol. 118, n° 4, p. 40004
European Physical Society/EDP Sciences/Società Italiana di Fisica/IOP Publishing
English Abstract
The effective diffusivity De of tracer particles diffusing in periodically corrugated axisymmetric two-and three-dimensional channels is studied. The majority of the previous studies of this class of problems are based on ...Read more >
The effective diffusivity De of tracer particles diffusing in periodically corrugated axisymmetric two-and three-dimensional channels is studied. The majority of the previous studies of this class of problems are based on perturbative analyses about narrow channels, where the problem can be reduced to an effectively one-dimensional one. Here we show how to analyze this class of problems using a much more general approach which even includes the limit of infinitely wide channels. Using the narrow-and wide-channel asymptotics, we provide a Padé approximant scheme that is able to describe the dispersion properties of a wide class of channels. Furthermore, we systematically identify all the exact asymptotic scaling regimes of De and the accompanying physical mechanisms that control dispersion, clarifying the distinction between smooth channels and compartmentalized ones, and identifying the regimes in which De can be linked to first passage problems.Read less <
English Keywords
mutual diffusion
Mass diffusion
including self-diffusion
Fluctuation phenomena
random processes
noise and Brownian motion
Classical transport
tracer diffusion
Origin
Hal imported