CFD-DEM 연계 모델 개발 및 세굴 현상에의 적용

Abstract

In this study, the Eulerian-Lagrangian approach was used to investigate the fluid flow and the behavior of sediment particles around a subsea pipeline exposed to a current. A solver was developed using the open-source libraries for computational fluid dynamics (CFD) and discrete element method (DEM). The solver used the averaging method based on the kernel function to overcome the grid dependency. To improve the accuracy of the drag force acting on the particle, a modified void fraction is presented in the drag model. The settling velocity of a single particle, the angle of repose, and the incipient motion of particles were simulated and compared with the experimental data to validate numerical methods. The ratio of the grid size to the particle size had no effect. This developed numerical solver was applied to a scour phenomenon around a subsea pipeline. The fluid flow around the subsea pipeline was analyzed and the motion of individual soil particles was tracked. It is possible to deepen the understanding of the scour phenomenon using the information on individual particles, which consider particle to particle interaction as well as the interaction between fluid and particles. Finally, the scour around the subsea pipeline was predicted and discussed.