Session: 01-01-02 Offshore Platforms II

Paper Number: 80564

80564 - Hydrodynamic Motion Behavior of Air-Cushion-Supported Hexagonal Floating Platform for Offshore Wind Turbine 

Yining He, Shinichiro Hirabayashi, Shigeru Tabeta, Toshio Nakajima, Yoshihiko Yamashita, Yuuki Yamashita, Motoko Imai 

 

heyining528@gmail.com

hirabayashi@k.u-tokyo.ac.jp

tabeta@k.u-tokyo.ac.jp

tmunakajima@gmail.com

yy730ajce@gmail.com

yamashita-yk@chodai.co.jp

imai-m@chodai.co.jp

 

Offshore wind is one of fast-growing renewable energy sources. Large areas with strong and stable wind power can be used for the development of offshore wind farms. The floating type platform is more suitable than the fixed type platform in the aera with large water depths. Cost-competitive floating platform with large stability will be demanded for increasing size of wind turbine.

This paper presents an initial experimental study of a new concept of floating platform supported by the air cushion. The platform consists of six hexahedron units with air cushion under the structure, having a moonpool in the middle. A 1:46 scale model was used for the measurement of motions in regular wave conditions. Heave and pitch motions of the platform and the shape of free surface in the air cushions and the moonpool were measured at the same time. To clarify the effect of the air cushion, a same shape barge-type model with a bottom was also tested. The results show that in short wave aeras, behaviors of the hexagonal air cushion platform are better than the hexagonal barge type platform, while in long wave aeras, behaviors are almost same.

In order to simulate and validate the stability of the platform in actual situation, a 1:46 scaled disc wind turbine model had been installed on the platform. The wind only testing, wave only testing and wind-wave coupling testing had been operated. The thrust on the wind turbine, the attitude and the hydrodynamic response of the whole structure had been measured. Results show that the hexagon air cushion platform is sufficiently stable for 5MW wind turbine.

 

Key words: air cushion platform, shape of free surface, offshore wind turbine, hexahedron.

Presenting Author: Yining He University of Tokyo

Authors:

Yining He University of Tokyo
Shinichiro Hirabayashi University of Tokyo
Shigeru Tabeta University of Tokyo
Toshio Nakajima Waterfront Real Estate Co
Yoshihiko Yamashita Waterfront Real Estate Co.
Yuuki Yamashita Business Strategy Promotion Division, Chodai Co.
Motoko Imai Business Strategy Promotion Division, Chodai Co.