Ocean carbon sequestration is a process of storing captured CO2 in the ocean, using liquid or solid forms of storage. Compared to liquid CO2 sequestration, dry ice ocean sequestration is simpler, more efficient, and has a larger capacity. However, research on the free-settling process of dry ice in ocean sequestration is still lacking, which limits the efficiency of dry ice ocean sequestration. In this study, the settling process of bullet-shaped dry ice is researched, and different models are established based on the main shape factors. The six-degree-of-freedom dynamic mesh is adopted to simulate the free settling of dry ice, and the mesh is kept near dry ice unchanged to ensure numerical simulation accuracy. The study shows that shapes with larger ellipticity of the front end have lower drag coefficients, and the shape factors mainly depend on ellipticity to influence the settling velocity. The correlation between Reynolds number and shape factors is obtained to predict the settling terminal velocity of bullet-shaped dry ice, providing a reference for the shape design of dry ice sequestration. This research provides theoretical support and practical guidance for efficient dry ice ocean sequestration.
Keywords Ocean sequestration, Free settling, Settling velocity, Shape factor