Vibrations and Their Control in Floating Offshore Wind Turbines

• Project/Area Number: 17K06229
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Dynamics/Control
• Research Institution: Hiroshima University
• Principal Investigator: IKEDA Takashi 広島大学, 工学研究科, 名誉教授 (50115523)
• Co-Investigator(Kenkyū-buntansha): 原田 祐志 愛知工業大学, 工学部, 准教授 (00456691)
• Project Period (FY): 2017-04-01 – 2020-03-31
• Project Status: Completed (Fiscal Year 2019)
• Budget Amount: ¥4,680,000 (Direct Cost: ¥3,600,000、Indirect Cost: ¥1,080,000); Fiscal Year 2019: ¥780,000 (Direct Cost: ¥600,000、Indirect Cost: ¥180,000); Fiscal Year 2018: ¥910,000 (Direct Cost: ¥700,000、Indirect Cost: ¥210,000); Fiscal Year 2017: ¥2,990,000 (Direct Cost: ¥2,300,000、Indirect Cost: ¥690,000)
• Keywords: 振動工学 / 浮体式洋上発電風車 / 浮体式プラットフォーム / 風車ブレード / 制振 / 回転体の振動 / 係数励振振動 / 局在化現象 / 機械力学・制御 / 振動 / 回転体

Outline of Final Research Achievements

This research theoretically and experimentally investigated the vibrations of floating offshore wind turbines and proposed some ideas of their control. In the blades of such wind turbines, parametrically excited vibrations might appear in the flapwise or chordwise direction because the platforms were subjected to vertical or horizontal motion due to ocean waves. When the three blades and the tower were coupled with each other, localization phenomena might occur in the blades which vibrated in different amplitudes. It was interpreted by analyzing the vibrations in a nonlinear oscillator array that the localization phenomena occurred when multiple vibrational modes simultaneously appeared. it was shown that liquid dampers and pendulum-type dynamic absorbers were effective in order to suppress the vibrations of the platform and blades, respectively.

Academic Significance and Societal Importance of the Research Achievements

浮体式洋上風車のブレードには，回転中に加わる重力の作用が周期的に変動し，かつ波浪による上下運動が作用するため，複雑な振動が発生する可能性が示されたことは学術的意義が大きい．また，風車プラットフォームやブレードの振動の制振対策として，液体ダンパーや振子型動吸振器が有効であることが示されたことは，今後，多くの浮体式洋上風車が導入されることが予想されることを考えると，信頼性・安全性の高い風車の開発，および国際的産業競争力の強化に貢献することができ，社会的意義も大きい．

Research Products

• [Journal Article] Parametric instability and localization of vibrations in three-blade wind turbines (2018)
  • Author(s): T. Ikeda, Y. Harata, Y. Ishida
  • Journal Title: Journal of Computational and Nonlinear Dynamics Volume: 13 Issue: 7 Pages: 1-11
  • DOI: 10.1115/1.4039899
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Presentation] Modal analysis to interpret localization phenomena of harmonic oscillations in nonlinear oscillator arrays (2019)
  • Author(s): Harata, Y., Ikeda, T.
  • Organizer: Proceedings of the ASME 2019 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference (IDETC/CIE2019)
  • Int'l Joint Research
• [Presentation] 鉛直励振を受ける浮体式洋上風車ブレードの面内振動 (2019)
  • Author(s): 原田祐志，立田典久，池田 隆
  • Organizer: 日本機械学会Dynamics & Design Conference 2019
• [Presentation] 複数の振動子列に生じる局在化現象のモード解析 (2019)
  • Author(s): 原田祐志，池田 隆
  • Organizer: 日本機械学会Dynamics & Design Conference 2019
• [Presentation] Parametric resonances of floating wind turbine blades under vertical wave excitation (2018)
  • Author(s): T. Ikeda, Y. Harata, Y. Miyazawa, Y. Ishida
  • Organizer: The 14th International Conference on Vibration Engineering and Technology of Machinery (VETOMAC XIV), Lisbon in Portugal, 10-13 September 2018
  • Int'l Joint Research
• [Presentation] 振子型動吸振器を用いた風車ブレードの制振解析 (2018)
  • Author(s): 谷尾総一郎，原田祐志，池田 隆，石田幸男
  • Organizer: 日本機械学会中国四国支部第56期総会・講演会
• [Presentation] 水平励振による浮体式風車ブレードの振動解析 (2018)
  • Author(s): 立田典久，原田祐志，池田 隆
  • Organizer: 日本機械学会中国四国支部第56期総会・講演会
• [Presentation] Suppression of structure’s roll motion using a tuned liquid damper (2017)
  • Author(s): T. Ikeda, Y. Harata, R. Nakamura
  • Organizer: International Conference on Engineering Vibration (ICoEV2017), Sofia in Bulgaria, 4-7 September 2017
  • Int'l Joint Research