5 / 2021-08-02 23:52:11

Numerical simulations of liquid-Solid flows in a vertical pipe by MPS-DEM coupling method

Moving particle semi-implicit method; Discrete element method; liquid-solid flow; Hydraulic conveying; MPSDEM-SJTU solver, periodic boundary condition.

With the further exploitation of deep-sea mineral resources, researchers have paid more attention to the hydraulic conveying. The minerals are transported from the sea bed to the floating structures through the pipe system with the help of seawater. It is necessary to investigate the flow regime and evaluate the attrition of the pipe.

Considering the severe sea condition, the pipeline may oscillate violently, resulting in the more complex liquid-solid flows int the pipeline. A coupled lagrangian-lagrangian method is used to solve such problems. Moving Particles Semi-implicit (MPS) method is adopted to simulate the movement of fluid while the Discrete Element Method (DEM) is employed to trace the motion of solid particles.  In the actual deep-sea hydraulic conveying, the pipeline is very long. Therefore, the periodic boundary condition is used to reduce the computation cost.

In this present work, an in-house solver MPSDEM-SJTU based on the improved MPS and DEM is developed. Firstly, a simulation of landslide-induced surges is conducted to verify the accuracy of this solver. Then, the liquid-solid flows in a vertical pipe are simulated. The influence of fluid velocity to the convey efficiency is investigated. Generally, the MPS-DEM method has the potential to deal with liquid-solid flows conveying problems.