The vertical pipeline systems integral to ocean engineering are crucial for the conveyance of fluid media, and thus pivotal in the harnessing of marine resources. This paper describes recent advances in the understanding of such flow dynamics, focusing on the motion of solid particles, vortex formation, and the resultant energy losses. An Eulerian–Lagrangian method is adopted in conjunction with advanced numerical simulations facilitated by Fluent–EDEM software, enabling a detailed examination of energy dissipation in two-phase flows. Utilizing entropy production theory, the entropy production rate within the main flow area is investigated, and its distribution across the pipeline’s cross-section is mapped, thereby providing novel insights into energy efficiency within fluid transport systems. The transient transport of solid particles is investigated, with vortex structures identified using both the Q criterion and vorticity analysis. The dynamic mode decomposition technique is used to obtain a clearer understanding of the distribution and evolution of vortex structures within the pipeline. The findings of this study underscore the respective effectiveness of vorticity analysis in detecting near-wall vortex structures and of the Q criterion in recognizing central flow area vortices. This study contributes to the body of knowledge in fluid dynamics by offering a comprehensive analysis of solid particle motion, vortex formation, and energy loss mechanisms, thereby providing a robust theoretical and technical foundation for the optimized design, operation, and maintenance of pipeline networks in ocean engineering.
Fan et al. (Mon,) studied this question.