PREDICTION OF EFFECTIVE DIFFUSIVITIES IN POROUS-MEDIA USING SPATIALLY PERIODIC MODELS
PREDICTION OF EFFECTIVE DIFFUSIVITIES IN POROUS-MEDIA USING SPATIALLY PERIODIC MODELS
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DOI：
10.1007/bf00179277
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发表时间：
1991-04-01
影响因子：
2.7
通讯作者：
RUSINEK, I
中科院分区：
文献类型：
--
作者：
SAEZ, AE;PERFETTI, JC;RUSINEK, I
计算三维、空间周期性多孔介质中的有效扩散率。 对于各向同性系统，我们发现，对于给定的孔隙率，有效扩散率的预测值与随机填充球体床的实验结果相匹配。 此外，三维几何产生的结果与之前使用二维表示的计算大致相同，表明有效扩散率对局部几何的相对不敏感。 对于二维模式失效的各向异性系统，我们发现，当使用一个可调参数采用三维模型时，垂直于层理平面的有效扩散率的预测有显着改进。 然而，三维模型高估了平行于层理平面的有效扩散率。
Calculations of effective diffusivities in three-dimensional, spatially periodic porous media are performed. For isotropic systems, it is found that, for a given porosity, the predicted value of the effective diffusivity matches experimental results for randomly-packed beds of spheres. Furthermore, the three-dimensional geometry yields approximately the same results as previous calculations employing two-dimensional representations, indicating a relative insensitivity of the effective diffusivity to local geometry. Regarding anisotropic systems, for which two-dimensional modes fail, it is found that there is a significant improvement in the prediction of the effective diffusivity perpendicular to the bedding plane when the three-dimensional model is employed using one adjustable parameter. However, the three-dimensional model overestimates the effective diffusivity parallel to the bedding plane.