2016 Fiscal Year Final Research Report

Investigation and Assessment of VIM Phenomenon on Semi-submersible Offshore Structures

Research Project

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Project/Area Number	26289344
Research Category	Grant-in-Aid for Scientific Research (B)
Allocation Type	Partial Multi-year Fund
Section	一般
Research Field	Naval and maritime engineering
Research Institution	National Institute of Maritime, Port and Aviation Technology
Principal Investigator	FUJIWARA Toshifumi 国立研究開発法人海上・港湾・航空技術研究所, その他部局等, 研究員 (10425754)
Co-Investigator(Kenkyū-buntansha)	齊藤昌勝国立研究開発法人海上・港湾・航空技術研究所, その他部局等, 研究員 (80359124) 二村正国立研究開発法人海上・港湾・航空技術研究所, その他部局等, 研究員 (00425753) 下里耕平国立研究開発法人海上・港湾・航空技術研究所, その他部局等, 研究員 (70726091) 松井亨介国立研究開発法人海上・港湾・航空技術研究所, その他部局等, 研究員 (00627606) 佐藤宏国立研究開発法人海上・港湾・航空技術研究所, その他部局等, 研究員 (70435775) 石田圭国立研究開発法人海上・港湾・航空技術研究所, その他部局等, 研究員 (60636827) 渡邊充史国立研究開発法人海上・港湾・航空技術研究所, その他部局等, 研究員 (20713788)
Project Period (FY)	2014-04-01 – 2017-03-31
Keywords	VIM / 渦励起動揺 / セミサブ浮体 / 模型試験 / レイノルズ数影響 / VIMシミュレーション / VIM振幅推定 / ISO
Outline of Final Research Achievements	Semi-submersible offshore structures are expected to be used in the Japanese coastal area for promoting resource exploitation and development. As the moored offshore structures are suffered from current, Vortex-induced Motion (VIM) effect should be assessed in an appropriate manner since the VIM causes fatigue damage of the structure’s mooring lines. VIM phenomenon on semi-submersible structures, however, is not clear, and its comprehension is insufficient. Then this research treated the VIM measurement test using large, small, and many forms of semi-submersible structure models to investigate the effect of column-column interval and lower hull volume for VIM amplitude, and shows the trends of VIM amplitude depending on current velocity and lower hull volume ratio for the first time. Moreover, using these results on the VIM amplitude for the models, the estimation method of VIM on a cylindrical and a semi-submersible offshore structure was newly proposed.
Free Research Field	船舶・海洋工学