2024 Volume 80 Issue 17 Article ID: 24-17188
In this study, hydraulic model experiments and CFD analyses were conducted to confirm the behavior of a spar-type floating body during upstanding and tipping in the construction of a spar-type offshore wind turbine. Water was pumped or drained into a 1/100 scale model of a floating body, and the trim angle and the maximum acceleration of the floating body were measured. Experiments were conducted under various conditions, including with and without bulkheads and with and without ballast material. When water is pumped or drained with crushed stone or sand as initial ballast, The ballast material collapsed, resulting in a sudden upstanding or tipping, and the trim angle oscillated with a short period, resulting in a maximum acceleration of 0.245G. Numerical simulations were performed without ballast material using a 3-D computational fluid dynamics tool. A spherical moving grid around the floating body was used in the analysis, and the results generally reproduced the experimental results. Furthermore, it was found that the eccentricity of the center of gravity had a significant effect on the upending and tipping behavior of the floating body.
