Geometry controlled dispersion in periodic corrugated channels
Geometry controlled dispersion in periodic corrugated channels
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DOI：
10.1209/0295-5075/118/40004
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发表时间：
2017-05-01
期刊：
影响因子：
1.8
通讯作者：
Dean, D. S.
中科院分区：
文献类型：
--
作者：
Mangeat, M.;Guerin, T.;Dean, D. S.
本文研究了示踪粒子在二维和三维周期性波纹轴对称通道中的有效扩散系数D-e。这类问题的大多数以前的研究是基于微扰分析的窄通道，在那里的问题可以减少到一个有效的一维。在这里，我们将展示如何使用更一般的方法来分析这类问题，甚至包括无限宽通道的限制。利用窄信道和宽信道的渐近性，我们给出了一个Pade近似方案，该方案能够描述宽信道的色散特性。此外，我们系统地确定所有的精确渐近标度制度的D-E和伴随的物理机制，控制色散，澄清光滑通道和分隔的区别，并确定制度，其中D-E可以连接到第一通道问题。版权所有（C）EPLA，2017.
The effective diffusivity D-e 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 Pade 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 D-e and the accompanying physical mechanisms that control dispersion, clarifying the distinction between smooth channels and compartmentalized ones, and identifying the regimes in which D-e can be linked to first passage problems. Copyright (C) EPLA, 2017.