An MPI parallel DEM-IMB-LBM framework for simulating fluid-solid interaction problems

The high-resolution DEM-IMB-LBM model can accurately describe pore-scale fluid-solid interactions, but its potential for use in geotechnical engineering analysis has not been fully unleashed due to its prohibitive computational costs. To overcome this limitation, a message passing interface (MPI) parallel DEM-IMB-LBM framework is proposed aimed at enhancing computation efficiency. This framework utilises a static domain decomposition scheme, with the entire computation domain being decomposed into multiple subdomains according to predefined processors. A detailed parallel strategy is employed for both contact detection and hydrodynamic force calculation. In particular, a particle ID re-numbering scheme is proposed to handle particle transitions across sub-domain interfaces. Two benchmarks are conducted to validate the accuracy and overall performance of the proposed framework. Subsequently, the framework is applied to simulate scenarios involving multi-particle sedimentation and submarine landslides. The numerical examples effectively demonstrate the robustness and applicability of the MPI parallel DEM-IMB-LBM framework. © 2024 Institute of Rock and Soil Mechanics, Chinese Academy of Sciences