Validation of LBM simulation of saturated seepage flow through 3D-printed homogeneous porous medium for fluid-particle coupled analysis

The accuracy of the pore-scale intergranular flow analysis by the lattice Boltzmann method (LBM), with the aid of the discrete element method (DEM), is investigated and compared with the experimental results of saturated seepage flows. Due to its simplicity and computational efficiency, a regularized Bhatnagar-Gross-Krook model is employed for the LBM to increase the numerical stability. After examining the performance of the numerical method by two well-known problems, namely the Hagen-Poiseuille flow and the flow past a stationary single sphere, a pore-scale numerical simulation of the saturated seepage flow is conducted. Permeability tests are carried out with an artificial porous medium prepared by a 3D printer, consisting of a sufficient number of resin particles. The experimental results are compared with those of the LBM numerical simulation, in which the pore structure of the porous medium is reproduced by the DEM. The numerical results are seen to have properly predicted the macroscopic properties obtained by the permeability tests, which have shown the prominent applicability of the LBM-DEM analysis to pore-scale intergranular fluid flows.