Liquid–gas and liquid–solid phase relationships are established in this study using the theories of cavitation nucleation and solid–liquid two-phase flow, respectively. The relationship between gas and solid phases is then derived, and the effect of solid phase parameter characteristics on the cavitation characteristics of the slurry-conveying slurry in the pump is analyzed. The influence law of particle concentration and speed on the airing performance of two-stage slurry pumps is studied on the basis of computational fluid mechanics. Results show that the cavitation phenomenon reduces the overall pressure of the flow field of deep-sea mining slurry pump. The lowest pressure area is the area of airing development at the entrance of the first-stage impeller blade. The cavitation of the mineral pulp pump becomes evident, and air bubbles rapidly spread over the outlet as the solid phrase particle grows in size. Moreover, solid phase concentration heightens the cavitation of the slurry pump. The cavitation in the pump gradually intensifies as the speed of the slurry pump increases, and a large area of air bubbles sharply forms and disturbs the flow field of the pump when the speed reaches 2000 r/min. In addition, the vortex increases, and the jet phenomenon becomes serious. A comprehensive analysis of the cavitation characteristics of the slurry pump is obtained at the following speed, solid phase volume concentration, and solid phase particle size: n = 1450 r/min, C = 5.3% and d = 20 mm, respectively.

The work simulates the transport pipeline movement of the marine dynamic environment based on the computational fluid dynamics research method. The present work also studies the influence of the marine dynamic environment on the solid–liquid two-phase flow field in the pipeline. An experimental study on the hydraulic transport flow law of natural gas hydrate pipeline is performed on the experimental platform of deep-sea mining metallogenic system fluctuation. Results show a large disturbance of the transverse swing convection field of pipelines and a small influence of axial vibration. The flow field distribution characteristics in the conveyor pipeline are consistent with the steady-state working conditions when the amplitude of transverse oscillation is less than 0.5 m. When the oscillation amplitude is larger than 2 m, the vibration has a considerable influence on the solid-phase distribution, solid–liquid two-phase velocity, dynamic and static pressure, and pressure loss of the flow field in the conveying system. The flow field distribution is chaotic when the transverse oscillation period of the pipeline is small. This condition becomes highly evident when the oscillation amplitude is large.

In order to quantitatively analyze the action mechanism of the pier flow field on the adjacent bow, Fluent was used to simulate the flow field variation characteristics of a single cylinder pier without ship passing. Secondly, the DES model and the dynamic grid technology are used to simulate the turbulence and the change of the ship’s bow moment when the ship passes through a single cylinder pier under different transverse distance parameters. The numerical simulation results under multiple working conditions show that when the ship approaches the pier, the bow moment is significantly affected by the flow field of the pier. With the increase of the distance between the pier and the ship, the influence of the pier flow field on the ship’s bow moment is gradually strengthened to gradually weakened.

This study proposes a new intermediate warehouse to prevent the problem that the ore in the vertical pipeline hydraulic lifting system blocks the nozzle during the process of being sucked into the lifting hard tube. A mathematical model and a finite element model of ore transport are established. Numerical simulation and experimental research are performed on the process of ore injection into the intermediate warehouse. Results show that the proposed intermediate warehouse has higher ore transmission efficiency, smaller pressure pulsation, and more stable transmission process compared with the traditional structure scheme. The larger the slurry conveying flow, the shorter the time required to convey the ore. In the process of slurry injection, the closer to the inlet, the more uneven the velocity distribution on the Z section, and the more concentrated the dynamic pressure. The closer to the lower end of the intermediate warehouse, the more dispersed the dynamic pressure, and the fluctuation of dynamic pressure in the intermediate warehouse is the main cause of unstable flow. The feed flow has a great influence on the stress state of the intermediate warehouse structure, the ore transfer time, and the stress decay period. The feed flow rate should be reasonably selected to meet the working requirements.