Optimum Design Method of the Group of Hexagonal Floating Platforms for Ocean Wind Farm

本研究的最终目标是计划开发大型海上风电场，该风电场由许多六角形浮动平台组成，用于利用海洋可再生能源。本研究所设计的浮式平台不同于桅杆式浮式海上风浮筒，对波浪间的横摇和俯伏运动具有稳定的特性，可作为太阳能帆板和波浪能装置的基座，包括六边形平台内的渔业活动等多种用途。单元平台由由桁架连接的6个垂直圆柱体支撑。利用相互作用理论计算了多浮体平台在波浪间的水动力力矩。为了保证浮式平台的安全，必须考虑极端环境条件下作用在平台上的波浪荷载和风荷载。计算流体力学（CFD）分析就是针对这种恶劣条件而应用和发展起来的。在水槽中进行了风浪作用下的模型试验。最后，在本研究的基础上确定了博多湾浮动平台的主要尺寸。自2011年12月起，直径18米的六角形平台安装在博多湾，并在一年的时间里在真实的海洋中进行各种测量，包括气象数据、风力涡轮机和太阳能电池板的电力以及平台的运动。

Final goal of the present study was planned to develop the large scale offshore wind farm consisting of the many numbers of the hexagonal floating platforms for the utilization of the ocean renewable energies. The floating platform of the present study is stable to the rolling and pitching motions among waves, deferent from the spar-type floating offshore wind buoy, and it is used for the multi-purpose such as the base of the solar panels and the wave power apparatus, including the fishery activities inside the hexagonal platform. A unit platform is supported by the 6 vertical cylinders which are connected by the truss. The hydrodynamic forces/moments of the platform among waves are calculated by the interaction theory for many numbers of floating bodies. For the safety of the floating platforms, the wave and wind loads acting on the platforms should be considered under the extreme environmental condition. The computational fluid dynamics(CFD) analysis is applied and developed for such severe conditions. The model tests under the winds and waves were conducted in the tank. Finally, the principal dimensions of the floating platform in Hakata Bay were determined on the basis of the present study. The hexagonal platform of 18m diameter has been installed in Hakata Bay since December 2011 and the various measurements including the meteorology data, the electric powers by the wind turbines and solar panels, and motions of the platform are undergoing in the real sea for one year.