Author(s): Runyu Xie; Pengzhi Lin
Linked Author(s): Pengzhi Lin
Keywords: Local scour Sediment movement Coarse-grained method CFD-DEM Immersed boundary method
Abstract: The study of local scour around subsea pipelines is crucial for ensuring pipeline stability and safety. This research presents a three-dimensional numerical investigation of local scour around subsea pipelines under combined wave-current conditions using a coupled CFD-DEM framework to capture fluid-particle interactions. The immersed boundary method (IBM) is employed to dynamically couple the pipeline with the surrounding flow field. To enhance computational efficiency, a coarse-grained DEM (CGDEM) approach is adopted, significantly reducing the computational cost associated with particle-resolved simulations. Model accuracy is validated against experimental data under clear-water conditions. Additionally, the effects of varying sediment gradation on scour depth and flow field evolution are examined. The analysis of particle dynamics under different Shields and Keulegan–Carpenter (KC) numbers provides empirical models for predicting local scour development.
Year: 2025