Influence of the Particle Shape, Size Distribution and Deposition Sequence on the Permeability of Porous Media

Research on the permeability of porous media plays a crucial role in advancing groundwater resource management and safeguarding environmental quality. In this study, the formation of three-dimensional complex porous media, influenced by particle shape, deposition sequence, and Particle Size Distribution (PSD), is simulated using the Discrete Element Method (DEM). The size distributions of pores and throats in these media are quantified with a ball-and-stick pore network model. Fluid-flow permeability and streamline patterns are then analysed using Lattice Boltzmann Method (LBM) simulations. Our results show that the permeability of porous media first decreases sharply and then becomes nearly constant as particle shape becomes more irregular. The deposition sequence of particles with different sizes has a strong impact on permeability and is identified as one of the main causes of permeability anisotropy. Within the scope of this study, when the average diameter of the skeleton particles is kept constant, changes in PSD only slightly modify the average pore and throat radii and porosity, so that the resulting permeability varies little. Overall, the process-based simulations demonstrate how grain-scale depositional conditions—represented by particle shape, grading, and layering—control the pore structure and permeability of porous media, thus providing a quantitative link between depositional environments and hydraulic properties.