Hydrodynamic Analysis of a Modular Floating Structure with Tension-Leg Platforms and Wave Energy Converters

et al. 2022

JMSE

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A novel modular floating structure (MFS) system moored by tension legs was proposed, which is composed of hexagonal floating modules, floating artificial reefs and wave energy converters (WECs). The integration of floating artificial reefs and WECs into the MFS can improve the marine environment and produce considerable electricity. The effects of both wave characteristics and the module quantity on the hydrodynamic responses of the MFS system were studied in depth, based on a time-domain numerical model. Both the modules’ hydrodynamic interaction effect and the connectors’ mechanical coupling effect were considered. The results indicate that floating artificial reefs combined with WECs can effectively reduce wave loads and convert wave energy into electricity for the MFS system. More modules involved in the MFS system could significantly reduce motion response and produced more wave energy output, which indicates that the MFS system is suitable for large-scale expansion. The effect of different power take-off (PTO) damping coefficients on the WECs’ performance was further investigated, and the optimal damping coefficient was recommended for the MFS system. Finally, the main extreme responses of the MFS system were further investigated, and its safety was checked thoroughly. One survival strategy was proposed, which could efficiently reduce extreme connector loads by more than 50%.

Section: Introductionmentioning

confidence: 61%

Section: Conceptual Design Of the Mfs Systemmentioning

confidence: 71%

Hydrodynamic Analysis of a Novel Modular Floating Structure System Integrated with Floating Artificial Reefs and Wave Energy Converters

et al. 2022

JMSE

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Hydrodynamic Responses of a Novel Modular Floating Structure System With Multi-Direction Expansion

Journal of Offshore Mechanics and Arctic Engineering

et al. 2022

In order to comprehensively utilize ocean resources and renewable energy, a novel modular floating structure (MFS) system with multi-direction expansibility has been proposed, which includes inner hexagonal tension leg platform (TLP) modules and outermost floating artificial reef modules coupled with the function of the wave energy converter (WEC). Considering both the hydrodynamic interaction effect and the mechanical coupling effect, main dynamic responses of the MFS system has been analyzed under different incident wave directions, and the corresponding physical mechanism has been clarified. Results indicate that connector loads slightly increase, but motion responses of the MFS system are more stable when the outermost floating artificial reefs serve as the up-wave modules. Outermost floating artificial reef modules have shown good wave-attenuation capacity for inner TLP modules, as well as producing considerable output wave power. The effect of key power take-off (PTO) parameters on the WECs performance has been investigated, and the optimal PTO damping coefficient has been suggested. In addition, extreme responses of the proposed MFS system have been further studied, and its safety has been well verified under typical extreme sea conditions. Main results in this work can serve as a helpful reference for the construction of future offshore floating cities.

Hydrodynamic Analysis of a Modular Integrated Floating Structure System Based on Dolphin-Fender Mooring

et al. 2022

JMSE

For both the expansion of important islands/reefs and the development of marine resources in South China Sea, a modular integrated floating structure (MIFS) system with tidal self-adaptation dolphin-fender mooring (DFM) has been proposed. The DFM, coupled with wave energy converters (WEC), can serve as an anti-motion system. Considering both the modules’ hydrodynamic interaction effect and the connectors’ mechanical coupling effect, both dynamic responses of the MIFS system and the WEC’s output power characteristics were investigated under typical sea conditions. Based on the comprehensive consideration of key factors (safety, economy, and comfort), the effects of both the DFM and module connectors were systematically studied for the MIFS system. Preliminarily optimal design parameters of corresponding connectors and WECs were suggested. The security of the MIFS system under extreme sea conditions was checked, and a promising survival strategy has been proposed. In addition, the modular expansion scheme of the MIFS system was further discussed, and the results indicated that the proposed MIFS system shows good expansibility. The WEC can not only improve both dynamic responses and the comfort of inner modules, but also make considerable wave energy contributions.