Study of motion performance of a floating system with four moonpools and a VAWT

Lei Tan, Satsuya Moritsu, Tomoki Ikoma, Yasuhiro Aida, Koichi Masuda

Research output: Chapter in Book/Report/Conference proceedingConference contribution

1 Citation (Scopus)

Abstract

In this paper the hydrodynamic performance of a barge-type floating foundation installed with four moonpools and a VAWT was investigated through model tests and theoretical calculations. The characteristics of wave-induced motion responses and tether tensions and the effects of turbine rotations were examined. Physical model tests were conducted in a wave tank using regular waves with the wave period ranging from 0.6 to 1.6 seconds and 0.01 or 0.02 meters in amplitude. A 2-MWclass VAWT was modelled with a scale ratio of 1/100 in the experiments. By varying the mass and the rotational speed of the turbine, gyroscopic moment effects were studied. In addition, numerical calculations based on the linear potential theory and Green function method were carried out to estimate motion responses and tether tensions. The present results indicate that the gyroscopic effect due to turbine rotations can be profound. It was found that the firstorder motions of the floating system were substantially reduced by the gyroscopic effect, while the second-order motions and tether tensions may be significantly increased. Moreover, the viscous damping of water motions in moonpools was found not negligible. As a result, theoretical models based on linear potential theory should be used with care in hydrodynamic analysis with regard to the floating systems with VAWT rotations. In addition, the present in-house program code was validated against WAMIT through comparing hydrodynamic predictions of a floating foundation with four moonpools, with reasonable agreement.

Original languageEnglish
Title of host publicationProceedings of the ASME 2021 3rd International Offshore Wind Technical Conference, IOWTC 2021
PublisherAmerican Society of Mechanical Engineers (ASME)
ISBN (Electronic)9780791884768
DOIs
Publication statusPublished - 2021
Externally publishedYes
EventASME 2021 3rd International Offshore Wind Technical Conference, IOWTC 2021 - Virtual, Online
Duration: Feb 16 2021Feb 17 2021

Publication series

NameProceedings of the ASME 2021 3rd International Offshore Wind Technical Conference, IOWTC 2021

Conference

ConferenceASME 2021 3rd International Offshore Wind Technical Conference, IOWTC 2021
CityVirtual, Online
Period2/16/212/17/21

All Science Journal Classification (ASJC) codes

  • Renewable Energy, Sustainability and the Environment

Fingerprint

Dive into the research topics of 'Study of motion performance of a floating system with four moonpools and a VAWT'. Together they form a unique fingerprint.

Cite this