Medial axis analysis of void structure in three-dimensional tomographic images of porous media
Medial axis analysis of void structure in three-dimensional tomographic images of porous media
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DOI：
10.1029/95jb03039
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发表时间：
1996-04-10
影响因子：
3.9
通讯作者：
Spanne, P
中科院分区：
文献类型：
--
作者：
Lindquist, WB;Lee, SM;Spanne, P
我们引入中轴线作为分析多孔介质中孔隙空间几何结构的工具，中轴线描绘了孔隙通道的基本几何形状。我们描述了一种算法，用于生成从X射线CAT扫描获得的多孔介质的数字化三维图像的空隙结构的中轴。中轴线是在迭代侵蚀过程中构建的，在每个步骤中，用通过侵蚀其体素的表面层获得的较小版本替换空隙结构的图像。该算法被施加到高（5 μ m）分辨率的显微断层图像的两个岩石芯片（伯里亚砂岩和丹麦白垩）和一个样本的均匀（100 μ m）直径，包装玻璃珠。我们统计调查的几个几何性质的结构BF中轴获得。第一个是相对体积的分布在每个侵蚀层的空隙空间。我们发现两个真实的岩石样品的分布是指数的，而包装玻璃珠的分布是正态的。研究的第二个属性是中轴线的断开段的体积分布，其与样品的断开的空隙段一一对应。我们发现的迹象，普遍的幂律行为管理的最小的断开件的体积分布。研究的最终行为是通过中轴的最短路径测量的几何弯曲度。这种弯曲度分布似乎可以用伽马分布很好地描述。
We introduce the medial axis as a tool in the analysis of geometric structure of void space in porous media, The medial axis traces the fundamental geometry of the void pathways. We describe an algorithm for generating the medial axis of the void structure from digitized three dimensional images of porous media obtained from X ray CAT scans. The medial axis is constructed during an iterative erosion procedure which, at each step, replaces the image of the void structure with a smaller version obtained by eroding its surface layer of voxels. The algorithm is applied to high (5 mu m) resolution microtomographic images of two rock chips (Berea sandstone and Danish chalk) and a sample pf uniform (100 mu m) diameter, packed glass beads. We statistically investigate several geometrical properties of the structure bf the medial axes obtained. The first is the distribution of relative volumes in each erosion layer of the void space. We find the distributions to be exponential for the two real rock samples and normal for the packed glass beads. The second property investigated is the distribution of volumes of disconnected segments of the medial axis which are in one-to-one correspondence with disconnected void segments of the sample. We find indications for a; universal power law behavior governing the distribution of volumes of the smallest disconnected pieces. The final behavior studied is a geometric tortuosity as measured by shortest paths through the medial axis. This tortuosity distribution appears well described by a gamma distribution.