Study of Hydraulic Properties of Uncoated Paper: Image Analysis and Pore-Scale Modeling
Study of Hydraulic Properties of Uncoated Paper: Image Analysis and Pore-Scale Modeling
复制标题
DOI：
10.1007/s11242-017-0909-x
复制
发表时间：
2017-08
影响因子：
2.7
通讯作者：
H. Aslannejad;S. Hassanizadeh
中科院分区：
文献类型：
--
作者：
H. Aslannejad;S. Hassanizadeh
在这项研究中，未涂布纸的特点。利用分辨率较高（0.9 μ m）的micro-CT扫描图像重建该层的三维结构。图像分析提供了层的孔隙空间，用于确定其孔隙率和孔径分布。通过计算不同域尺寸的孔隙度和渗透率值来确定代表性单元体积（REV）尺寸。我们发现，当磁畴尺寸为400 × 400 × 150 μ m^ 3，400× 400× 150 μ m ^3或更大时，这些值保持不变;这被选为REV尺寸。确定的REV大小进行了验证，通过确定毛细管压力-饱和吸渗曲线为各种域的大小。我们通过模拟水从不同方向渗透到地层中，研究了曲线的方向依赖性。我们没有发现不同方向的曲线之间有任何显著差异。我们研究了纸张压缩对曲线的影响。我们发现，纸层的高达30%的压缩对曲线的影响非常小。还计算了相对渗透率随饱和度的变化。使用共聚焦激光扫描显微镜观察水渗透到纸中。本文中的水流动态可视化显示，水首先沿着纤维移动，然后填充它们之间的孔隙。
In this study, uncoated paper was characterized. Three-dimensional structure of the layer was reconstructed using imaging results of micro-CT scanning with a relatively high resolution (0.9~\upmu m)(0.9 μ m). Image analysis provided the pore space of the layer, which was used to determine its porosity and pore size distribution. Representative elementary volume (REV) size was determined by calculating values of porosity and permeability values for varying domain sizes. We found that those values remained unchanged for domain sizes of 400 * 400 * 150\,\upmu m^ 3 400× 400× 150 μ m 3 and larger; this was chosen as the REV size. The determined REV size was verified by determining capillary pressure–saturation imbibition curves for various domain sizes. We studied the directional dependence of curves by simulating water penetration into the layer from various directions. We did not find any significant difference between curves in different directions. We studied the effect of compression of paper on curves. We found that up to 30% compression of the paper layer had very small effect on the curve. Relative permeability as a function of saturation was also calculated. Water penetration into paper was visualized using confocal laser scanning microscopy. Dynamic visualization of water flow in the paper showed that water moves along the fibers first and then fills the pores between them.