Numerical and experimental investigations on pipeline internal solid-liquid mixed fluid for deep ocean mining

Abstract

Pipeline internal flow has a significant influence on the transportation process of the entire deep ocean mining. Since the internal flow is a solid-liquid mixed fluid, the CFD-DEM coupling method is adopted for numerical simulation. The pipeline internal flow field at different flow rates and particle concentration is simulated by connecting program Fluent and EDEM, and the distribution of pressure and wall shear stress is calculated. A laboratory experiment is carried out by establishing a vertical lifting pipeline experiment system. The movement characteristics and laws of nodules with different flow rates and particle sizes during the lifting process are further analyzed. The result is basically consistent between numerical simulation and experiment, which verifies the reliability of the simulation. The results show that the internal flow velocity and the particle concentration affect the stress and transportation performance of the mining pipeline. Relevant recommendations for the stability and efficiency of the deep-sea mining pipeline transportation system are summarized through the results. The research provides theoretical and technical references for the optimization design, performance prediction, and operation control of the deep ocean mining pipeline system.