In recent years, with the development of ship and ocean engineering to the deep sea, people pay more and more attention to the ore mining and transportation in the deep sea. Deep sea mineral transportation involves horizontal pipeline transportation. The horizontal pipeline has the characteristics of large slenderness ratio and high liquid velocity. Considering the complexity of this problem and the problem of solid-liquid two-phase flow, this paper intends to study this problem by using the combination of moving particle semi implicit method (MPS) and discrete element method (DEM). It is a new attempt to use MPS method to simulate liquid flow in pipeline, and DEM method is a particle numerical method based on discontinuous medium assumption, which is especially suitable for solving solid particles in mixed transportation by averaging ore shape with spherically shaped solid particles.
The process and details of mixed transportation in ultra long horizontal pipeline are not clear. In this paper, periodic boundary conditions are used to splice multiple sections of pipes to form an ultra long horizontal pipeline. Based on the MPSDEM-SJTU solver independently developed by our research group, the particle motion state and flow field information under different solid particle concentration conditions are analyzed. These results are expected to provide reference for setting transportation parameters and optimizing transportation conditions.
In recent years, the mining of marine ore has gradually attracted people's attention. Chung et al. (2021) made some summary work on deep-sea mining. Generally speaking, the length of the horizontal pipeline is very large so that the liquid-solid two-phase flow problem involved is very complicated. Oh J, Jung J (2015, 2018) did series work. What's more, when the liquid flow rate in the pipeline is small, it will cause the solid particles to accumulate and block in the pipeline, so the liquid flow rate in the horizontal pipeline is generally set to be large. Miedema SA (2015) have done research in this area. Senapati PK, Mishra BK, Parida A (2013) found that after full development, the Reynolds number in the pipeline is very large, which will generate a lot of large turbulence, moreover, the shape, quantity and position of the solid particles are uncertain, there will be many difficulties in analyzing the problem.
