The transverse permeability of disordered fiber arrays: a statistical correlation in terms of the mean nearest interfiber spacing
The transverse permeability of disordered fiber arrays: a statistical correlation in terms of the mean nearest interfiber spacing
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DOI：
10.1007/s11242-007-9123-6
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发表时间：
2008-01-01
影响因子：
2.7
通讯作者：
Papathanasiou, Thanasis D.
中科院分区：
文献类型：
--
作者：
Chen, Xiaoming;Papathanasiou, Thanasis D.
在多孔介质文献中，单向纤维系统被广泛地分类为有序或无序。前一类，易于处理的分析目的，但限制在其关系到现实，涉及正方形，六边形和各种交错阵列。后一类涉及其他一切。虽然有序纤维介质的无量纲水力渗透率已知是其孔隙度Delta的确定性函数，但影响无序纤维阵列渗透率的参数还没有很好地理解。本研究的目的是通过计算研究流过许多单向阵列的随机放置的纤维，并得出K和一些措施，他们的微观结构之间的相关性。在这个过程中，我们解释了计算和实验观察到的渗透率值的广泛分散。这一任务是通过边界元法（BEM）的并行实现实现的。超过600模拟进行了由576个纤维横截面放置在一个正方形的单元格由Monte Carlo程序的二维几何形状。孔隙度从0.45到0.90不等。计算的磁导率与早期的理论结果和实验数据进行了比较。对计算结果的分析表明，当纤维分布的不均匀性增加时，φ < 0.7的无序阵列的磁导率降低。这种减少在低孔隙率下可以是显著的。本研究的关键发现是K和平均最近纤维间间距Δ（-）1之间的直接相关性，后者取决于纤维介质的微观结构。
In the porous media literature, unidirectional fibrous systems are broadly categorized as ordered or disordered. The former class, easily tractable for analysis purposes but limited in its relation to reality, involves square, hexagonal and various staggered arrays. The latter class involves everything else. While the dimensionless hydraulic permeability of ordered fibrous media is known to be a deterministic function of their porosity Delta, the parameters affecting the permeability of disordered fiber arrays are not very well understood. The objective of this study is to computationally investigate flow across many unidirectional arrays of randomly placed fibers and derive a correlation between K and some measure of their microstructure. In the process, we explain the wide scatter in permeability values observed computationally as well as experimentally. This task is achieved using a parallel implementation of the Boundary Element Method (BEM). Over 600 simulations are carried out in two-dimensional geometries consisting of 576 fiber cross-sections placed within a square unit cell by a Monte Carlo procedure. The porosity varies from 0.45 to 0.90. The computed permeabilities are compared with earlier theoretical results and experimental data. Analysis of the computational results reveals that the permeability of disordered arrays with phi < 0.7 is reduced as the non-uniformity of the fiber distribution increases. This reduction can be substantial at low porosities. The key finding of this study is a direct correlation between K and the mean nearest inter-fiber spacing delta(-)1, the latter depending on the microstructure of the fibrous medium.