Diffusion in a tube of varying cross section: Numerical study of reduction to effective one-dimensional description
Diffusion in a tube of varying cross section: Numerical study of reduction to effective one-dimensional description
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DOI：
10.1063/1.2719193
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发表时间：
2007-04-07
影响因子：
4.4
通讯作者：
Bezrukov, S. M.
中科院分区：
文献类型：
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作者：
Berezhkovskii, A. M.;Pustovoit, M. A.;Bezrukov, S. M.
用布朗动力学方法模拟了颗粒在长圆锥管(管长远大于其最小半径)中的扩散，研究了变截面管内的三维扩散简化为有效的一维描述。作者发现，Zwanzig[J.Phys.]提出的具有位置相关扩散系数D(X)的Fick-Jacobs方程形式的一维描述。化学。96,3926(1992)]，D(X)由Rguera-Rubi公式[Phys.修订，061106(2001年)]，D(X)=D/根1+R-‘(X)(2)，其中D是无约束下的粒子扩散系数，R(X)是x处的管子半径，当竖杆R-’(X)竖杆时有效
Brownian dynamics simulations of the particle diffusing in a long conical tube (the length of the tube is much greater than its smallest radius) are used to study reduction of the three-dimensional diffusion in tubes of varying cross section to an effective one-dimensional description. The authors find that the one-dimensional description in the form of the Fick-Jacobs equation with a position-dependent diffusion coefficient, D(x), suggested by Zwanzig [J. Phys. Chem. 96, 3926 (1992)], with D(x) given by the Reguera-Rubi formula [Phys. Rev. E 64, 061106 (2001)], D(x)=D/root 1+R-'(x)(2), where D is the particle diffusion coefficient in the absence of constraints, and R(x) is the tube radius at x, is valid when vertical bar R-'(x)vertical bar