A pipe domain seepage model based on outsourcing Voronoi network with particle flow code

The seepage stability of rock and soil and the interaction between water, rock, and soil are important problems in hydropower engineering. The limits of fluid-solid coupling in the Particle Flow Code are addressed in this study by the proposal of an enhanced mesh generation algorithm based on an outsourced Voronoi polygon. The proposed algorithm divides the pipeline into real pipeline and virtual pipeline through active contact and inactive contact to better reflect the seepage process of fluid in the soil-rock mixture (SRM). During the course of a homogenous sample flow, it is utilized to examine changes in pore pressure and flow rate distribution. The results show that the improved algorithm can simulate 1D steady seepage well, and during the steady flow of the sample, the seepage law follows Darcy's law. The improved algorithm is applied to the study of heterogeneous seepage characteristics, and a discrete element seepage model of heterogeneous particles is established. From the aspects of pore water pressure, percolation field analysis and permeability coefficient of the SRM, the influence of the structural effect of the SRM on its percolation characteristics is analyzed. The results show that the unique organizational structure characteristics of the earth rock mixture lead to remarkable differences between its seepage characteristics and the seepage field and homogeneous materials. The results can offer theoretical backing for the investigation of seepage failure of a soil-rock-mixed slope under rainfall.