Abstract The flow and transport behaviors in porous media are closely linked to the structure and morphology of the pore space. A fundamental objective of most studies of porous media is to link the pore structure to the hydraulic functions, such as the permeability, capillary pressure and diffusivity, which are necessary for engineering applications. In this paper, an attempt is made to build a direct link between the hydraulic functions and the morphological measures of diverse porous media. Porous columns with different structures and morphologies are generated by randomly packing grains with different shapes and sizes. The pore structure of the repacked porous media is visualized through X-ray computed tomography and quantified by a series of parameters, including the set of Minkowski functionals, diverse characteristic pore sizes, geometric tortuosity and fractal dimension. The intrinsic permeability, molecular diffusivity and apparent thermal conductivity of the repacked porous media are simulated numerically. The Minkowski functionals have the capacity to characterize the microscale complex pore domain of the porous media in a macroscale way. A good linear relationship is shown among the effective pore size, nominal opening dimension and critical pore neck size obtained from the morphological analysis regardless of the shapes and sizes of the grains. The three different pores may serve as the characteristic pore correlation to the intrinsic permeability. The Kozeny-Carman equation can be used to mimic the intrinsic permeability and to serve as a quality-control tool for porous media with different grain angularities. A topologically based model can generally provide a single relationship for porous media randomly repacked with grains of different angularities. The molecular diffusivity of angular grains is found to be larger than that of round ones. The molecular diffusivity is linearly related to the porosity and fractal dimension. Porous media repacked with round grains tend to attain denser packing, a higher number of contacts per unit volume and higher thermal conductivity than media packed with angular particles. The apparent thermal conductivity has a negative linear correlation to the porosity and fractal dimension of porous media with different grain morphologies.

中文翻译：

---

孔结构和形态对不同角度随机重装颗粒流动和输运特性的影响

摘要 多孔介质中的流动和输运行为与孔隙空间的结构和形态密切相关。大多数多孔介质研究的一个基本目标是将孔隙结构与工程应用所必需的水力函数联系起来，例如渗透率、毛细管压力和扩散率。在本文中，试图在水力函数和不同多孔介质的形态测量之间建立直接联系。不同结构和形态的多孔柱是由不同形状和大小的颗粒随机堆积而成。重新填充的多孔介质的孔隙结构通过 X 射线计算机断层扫描进行可视化，并通过一系列参数进行量化，包括一组 Minkowski 泛函、不同的特征孔径、几何曲折度和分形维数。数值模拟了重新填充的多孔介质的固有渗透率、分子扩散率和表观热导率。Minkowski 泛函具有以宏观方式表征多孔介质的微观复杂孔隙域的能力。无论晶粒的形状和尺寸如何，从形态分析中获得的有效孔径、标称开口尺寸和临界孔颈尺寸之间都显示出良好的线性关系。这三种不同的孔隙可以作为与固有渗透率的特征孔隙相关性。Kozeny-Carman 方程可用于模拟固有渗透率，并用作具有不同晶粒角度的多孔介质的质量控制工具。基于拓扑的模型通常可以为随机重新填充不同角度的颗粒的多孔介质提供单一关系。发现有角晶粒的分子扩散系数大于圆形晶粒的分子扩散系数。分子扩散率与孔隙率和分形维数线性相关。用圆形颗粒重新填充的多孔介质往往比用角形颗粒填充的介质获得更密实的填充、每单位体积的更多接触次数和更高的热导率。表观热导率与具有不同颗粒形态的多孔介质的孔隙率和分形维数呈负线性相关。分子扩散率与孔隙率和分形维数线性相关。用圆形颗粒重新填充的多孔介质往往比用角形颗粒填充的介质获得更密实的填充、每单位体积的更多接触次数和更高的热导率。表观热导率与具有不同颗粒形态的多孔介质的孔隙率和分形维数呈负线性相关。分子扩散率与孔隙率和分形维数线性相关。用圆形颗粒重新填充的多孔介质往往比用角形颗粒填充的介质获得更密实的填充、每单位体积的更多接触次数和更高的热导率。表观热导率与具有不同颗粒形态的多孔介质的孔隙率和分形维数呈负线性相关。