The effective reaction rate and diffusion coefficients for a two‐phase medium
The effective reaction rate and diffusion coefficients for a two‐phase medium
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两相介质的有效反应速率和扩散系数
DOI：
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发表时间：
1983
期刊：
影响因子：
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通讯作者：
R. Kapral
中科院分区：
文献类型：
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作者：
D. Bedeaux;R. Kapral
计算由在两相介质中移动的小颗粒集合组成的系统的输运特性。假设一相精细地分散在另一相中，因此与系统的尺寸相比，均匀区域很小。颗粒可以在任一相中扩散和反应（消失）。针对各种情况下两相的任意体积分数计算粗粒度（有效）反应速率和扩散系数。该计算利用背景率和扩散系数的引入来激发自密度场和局部密度场的定义。这些场的引入以及一相夹杂物在另一相中的随机分布的假设相结合，可以得出所有体积分数的有效传输系数的合理近似值。给出了模型计算的结果。
The transport properties of a system composed of an ensemble of small particles moving in a two‐phase medium are calculated. One phase is assumed to be finely dispersed in the other so that the homogeneous regions are small compared to the size of the system. The particles may diffuse and react (disappear) in either phase. The coarse‐grained (effective) reaction rate and diffusion coefficients are calculated for arbitrary volume fractions of the two phases for various cases. The calculation utilizes the introduction of background rate and diffusion coefficients to motivate the definition of self‐ and local density fields. The introduction of these fields in conjunction with the assumption of the random distribution of the inclusions of one phase in the other leads to reasonable approximations for the effective transport coefficient for all volume fractions. The result of model calculations are presented.