Session: 04-04-05 Free Spans and Routing

Paper Number: 126409

126409 - Numerical Simulation of Ascending Motion of Polymetallic Nodules for Hydraulic Lifting of Vertical Pipes 

Deep-sea polymetallic nodule hydraulic lifting program belongs to the particle fluid complex system of solid-liquid two-phase flow problems, most of the previous research for low-density, small-sized particles, for high-density, large-sized particles of the research is mostly carried out in the net water free-fall problem.In this paper, the solid-liquid two-phase flow of seawater with polymetallic nodules was numerically calculated using the CFD-DEM semi-analytical method in the context of deep-sea mining polymetallic combined with hydraulic lifting.The effect on the particle rise process was investigated for several cases, such as the particle fluid density ratio of 1:2, different pipe diameters with particle size ratios of (2~10), different pipe Reynolds numbers (400~2000; lifting velocities of 2~10m/s), and different initial positions of the particles. The accuracy of the computational model is also verified by comparing the infinite-boundary free-fall experiments with the results of the literature by Lei Liu and Horowitz M. The results are summarized as follows. Through numerical simulation, five subdivided types of particle ascent trajectories were obtained: spiral rising motion in space, tilted oscillating rising motion in space, "s" shaped rising and then vertical rising motion in the plane, inclined ascent in the plane, and vertical straight rising motion; In the same Reynolds number, with the pipe diameter particle size ratio decreases, the particles rising trajectory tends to rise vertically; in the same pipe diameter particle size ratio, with the increase of the pipe Reynolds number, the particles rising trajectory also tends to rise vertically; in the same pipeline Reynolds number, the pipe diameter particle size ratio, the type of particles of the rising trajectory of the different initial position is the same, just the curve of the rising trajectory fluctuations, and the change of the initial location of the particles rising speed has a tiny effect.In summary, the type of upward trajectory of particles during hydraulic lifting of the pipe is related to the pipe Reynolds number and the pipe diameter particle size ratio.

Presenting Author: Yajiao Liu Jiangsu University of Science and Technology

Presenting Author Biography: Liu Yajiao, 2000, bachelor's degree, engaged in research related to the development of marineresources and environmental protection

Authors:

Yajiao Liu Jiangsu University of Science and Technology
Peilin Dou Jiangsu University of Science and Technology
Xiu Li Jiangsu University of Science and Technology