Abstract:

The movement of hydrate and sand particles in submarine hydrate mining is still unclear. Therefore, in this study, the coupling method of the discrete element method (DEM) and computational fluid dynamics (CFD) is adopted to study the movement of hydrate and sand particles at the seabed. To verify the proposed method, the settling of spherical particles is simulated and compared with experimental findings. The feasibility of the proposed method is illustrated. Moreover, numerical simulations of a single sand particle and a single hydrate particle are performed using the DEM-CFD coupling method. Various particle positions, velocities, forces, and angular velocities are analyzed during particle movement. Simulation results show that the sand particles settle at the bottom of the container and collide when they reach the bottom while rotating simultaneously. The hydrate particles float upward without rotation. Finally, a numerical simulation of a particle swarm is performed in a closed container to show that the DEM-CFD coupling method can simulate complex flow with a large number of particles and analyze the particle force and movement at the microscopic scale. This study provides a reliable and effective method for multiphase flow research on hydrate and sand particles.

Key words: :discrete element method, computational fluid dynamics, numerical simulation, hydrate particle, sand particle, particle movement, force analysis