Session: 01-01-02 Offshore Platforms II

Paper Number: 79942

79942 - Investigations On The Effects Of Internal Liquid Sloshing of Semi-Submersible Floating Offshore Wind Turbines 

The offshore wind industry has experienced significant growth in recent years and continues to expand worldwide. Compared with onshore/bottom fixed wind turbines, the floating offshore wind turbines (FOWTs) are susceptible to complex and harsh environmental conditions induced by high crest waves and windstorms. Thus, it is important to evaluate the stability and survivability of FOWTs at the design stage. On the other hand, for normal operations and optimal power outputs, the motion of a FOWT must be restricted to an acceptable level. As one of the promising passive control systems in the offshore industry, Tuned Liquid Column Dampers (TLCDs) have been used to dissipate the wave energy and mitigate the rotational motions of the floating structures (Hochrainer, 2005) (Yu and Cheng, 2020). Although the technology has been widely adopted in the ship industry, its applicability to FOWTs remain unclear. The present study is, therefore, aimed at investigating the feasibility of integrating a TLCD into the support structure of a semi-submersible FOWT and its effectiveness in reducing wave induced platform motions by using a high-fidelity computational fluid dynamics (CFD) model. The adopted numerical model, which is based on the OpenFOAM CFD package, is first validated using test cases of liquid sloshing inside a multiple-column liquid damper under various external excitations. To examine the effects of TLCDs, platform motions under wave load only and combined wave and sloshing loads will be simulated and compared. A particular focus will be on the effects of TLCD configurations including their sizes and mass ratios on loading and motion reductions and hence their performance and optimal design.

References

Hochrainer, M., 2005. Tuned liquid column damper for structural control. Acta Mechanica 175, 57-76.

Yu, W., Cheng, P.W., 2020. Verification of a Passive Tuned Liquid Multi-Column Damper for Floating Wind

Presenting Author: Yang Zhou Manchester Metropolitan University

Authors:

Yang Zhou Manchester Metropolitan University
Ling Qian manchester metropolitan university
Wei Bai manchester metropolitan university
Zaibin Lin manchester metropolitan university