Effects of WEC Geometry on the Performance of a WEC Array-VLFS Integrated System

Zhiyang Zhang; Linpei Dai; Ziheng Wang; Haitao Wu

doi:10.2478/pomr-2026-0006

Abstract

This study focuses on analysing the effects of wave energy converter (WEC) geometry on the performance of an integrated system comprising a WEC array and a very large floating structure (VLFS). A numerical model of the integrated system is established based on multi-body potential theory, the discrete-module-beam (DMB) method, and the Lagrange multiplier technique. After validating the accuracy of the simulation approach, the present study examines the energy capture efficiency and hydroelastic response of the integrated system with various WEC geometry parameters, including length, width, draft, and shape. Owing to the complexity of the physical model of the integrated system, it is difficult to determine the optimal Power Take-Off (PTO) damping coefficient analytically. Therefore, a numerical search method is employed to obtain the PTO damping coefficients corresponding to different WEC geometry parameters. After a series of numerical simulations, the results reveal that, compared to the other three geometry parameters, the power output of the integrated system is more sensitive to the WEC length. Moreover, the incorporation of the WEC array leads to a significant reduction in the hydroelastic response of the VLFS. In addition, the draft and shape of the WEC exhibit limited influence on the structural response of the VLFS. All in all, the analytical methodology and framework presented in this paper can offer some insights for the design of similar integrated systems.

References

Shi X, Liang B, Du S, Shao Z, Li S. Wave energy assessment in the China East Adjacent Seas based on a 25-year wave-current interaction numerical simulation. Renewable Energy 2022. https://doi.org/10.1016/j.renene.2022.09.094.
Search in Google Scholar Back to article
Gao H, Biao L. Establishment of Motion Model for Wave Capture Buoy and Research on Hydrodynamic Performance of Floating-Type Wave Energy Converter. Polish Maritime Research 2015. https://doi.org/10.1515/pomr-2015-0041.
Search in Google Scholar Back to article
Zhang Z, Guan L, Wu H, Wu L, Liu W, Cui L. Effects of the second-order hydrodynamics on the dynamic behavior of the platform among the wind-wave hybrid systems. Journal of Engineering Research 2024. https://doi.org/10.1016/j.jer.2024.04.003.
Search in Google Scholar Back to article
Abbas N, Barbahan M, Kabrial Y, Kabrial A. A Novel Approach to Wave Energy Conversion Using CFD Technique. Polish Maritime Research 2024. https://doi.org/10.2478/pomr-2024-0041.
Search in Google Scholar Back to article
Cui L, Wu H, Li M, Lu M, Liu W, Zhang Z. Effects of mooring failure on the dynamic behavior of the power capture platforms. Energy 2024. https://doi.org/10.1016/j.energy.2024.133761.
Search in Google Scholar Back to article
Zhang W, Zhu Y, Liu S, Wang J, Zhang W. Evaluation of Geometrical Influence on the Hydrodynamic Characteristics and Power Absorption of Vertical Axisymmetric Wave Energy Converters in Irregular Waves. Polish Maritime Research 2023. https://doi.org/10.2478/pomr-2023-0029.
Search in Google Scholar Back to article
Zhang X, Tian X, Xiao L, Li X, Lu W. Mechanism and sensitivity for broadband energy harvesting of an adaptive bi-stable point absorber wave energy converter. Energy 2019. https://doi.org/10.1016/j.energy.2019.115984.
Search in Google Scholar Back to article
Wu H, Yuan Z. Numerical investigation of the effects of short-crested irregular waves on the performance of a floating power capture platform. Ocean Engineering 2024. https://doi.org/10.1016/j.oceaneng.2024.119548.
Search in Google Scholar Back to article
He F, Huang Z, Law A-K. An experimental study of a floating breakwater with asymmetric pneumatic chambers for wave energy extraction. Applied Energy 2013. https://doi.org/10.1016/j.apenergy.2013.01.013.
Search in Google Scholar Back to article
Zhao X, Ning D, Zhang C, Liu Y, Kang H. Analytical study on an oscillating buoy wave energy converter integrated into a fixed box-type breakwater. Mathematical Problems in Engineering 2017. https://doi.org/10.1155/2017/3960401.
Search in Google Scholar Back to article
Ning D-Z, Zhao X-L, Zhao M, Hann M, Kang H-G. Analytical investigation of hydrodynamic performance of a dual pontoon WEC-type breakwater. Applied Ocean Research 2017. https://doi.org/10.1016/j.apor.2017.03.012.
Search in Google Scholar Back to article
Zhang H, Zhou B, Zang J, Vogel C, Jin P, Ning D. Optimisation of a three-dimensional hybrid system combining a floating breakwater and a wave energy converter array. Energy Conversion and Management 2021. https://doi.org/10.1016/j.enconman.2021.114717.
Search in Google Scholar Back to article
Zhou B, Lin C, Huang X, Zhang Q, Yuming Y, Zhang H, Jin P, Yang Y. Hydrodynamic performance and narrow gap resonance of WEC-floating breakwater hybrid system: An experimental study. Ocean Engineering 2025. https://doi.org/10.1016/j.oceaneng.2025.121040.
Search in Google Scholar Back to article
Gao RP, Tay ZY, Wang CM, Koh CG. Hydroelastic response of very large floating structure with a flexible line connection. Ocean Engineering 2011. https://doi.org/10.1016/j.oceaneng.2011.09.021.
Search in Google Scholar Back to article
Tay ZY. Energy extraction from an articulated plate anti-motion device of a very large floating structure under irregular waves. Renewable Energy 2019. https://doi.org/10.1016/j.renene.2018.06.044.
Search in Google Scholar Back to article
Nguyen HP, Wang CM, Flocard F, Pedroso DM. Extracting energy while reducing hydroelastic responses of VLFS using a modular raft WEC-type attachment. Applied Ocean Research 2019. https://doi.org/10.1016/j.apor.2018.11.016.
Search in Google Scholar Back to article
Cheng Y, Xi C, Dai S, Ji C, Collu M, Li M, Yuan Z, Incecik A. Wave energy extraction and hydroelastic response reduction of modular floating breakwaters as array wave energy converters integrated into a very large floating structure. Applied Energy 2022. https://doi.org/10.1016/j.apenergy.2021.117953.
Search in Google Scholar Back to article
Zhao X, Xue F, Chen L, Göteman M, Han D, Geng J, Sun S. Hydrodynamic analysis of a floating platform coupled with an array of oscillating bodies. Ocean Engineering 2023. https://doi.org/10.1016/j.oceaneng.2023.115439.
Search in Google Scholar Back to article
Lu D, Fu S, Zhang X, Guo F, Gao Y. A method to estimate the hydroelastic behaviour of VLFS based on multi-rigid-body dynamics and beam bending. Ships and Offshore Structures 2016. https://doi.org/10.1080/17445302.2016.1186332.
Search in Google Scholar Back to article
Sun L, Taylor RE, Choo YS. Responses of interconnected floating bodies. IES Journal Part A: Civil & Structural Engineering 2011. https://doi.org/10.1080/19373260.2011.577933.
Search in Google Scholar Back to article
Hess JL, Smith AMO. Calculation of non-lifting potential flow about arbitrary three-dimensional bodies. Journal of Ship Research 1964. https://doi.org/10.5957/jsr.1964.8.4.22.
Search in Google Scholar Back to article
Wu H, Liao B, Deng W, Yuan Z. Effects of hinge properties on the hydroelastic response of an interconnected very large floating structure under wave–current interactions. Physics of Fluids 2025. https://doi.org/10.1063/5.0280962.
Search in Google Scholar Back to article
Wei W, Fu S, Moan T, Lu Z, Deng S. A discrete-modules-based frequency domain hydroelasticity method for floating structures in inhomogeneous sea conditions. Journal of Fluids and Structures 2017. https://doi.org/10.1016/j.jfluidstructs.2017.06.002.
Search in Google Scholar Back to article
Zhang D-Q, Yuan Z-M, Zhao G-W, Chen Y-J, Du J-F. An experimental and numerical study of motion responses of multi-body arrays with hinge connections. Journal of Marine Science and Engineering 2024. https://doi.org/10.3390/jmse12101791.
Search in Google Scholar Back to article
Yuan Z, Incecik A, Dai S, Alexander D, Ji C, Zhang X. Hydrodynamic interactions between two ships travelling or stationary in shallow waters. Ocean Engineering 2015. https://doi.org/10.1016/j.oceaneng.2015.08.058.
Search in Google Scholar Back to article
Newman JN. Wave effects on deformable bodies. Applied Ocean Research 1994. https://doi.org/10.1016/0141-1187(94)90013-2.
Search in Google Scholar Back to article
Yago K, Endo H. On the hydroelastic response of box-shaped floating structure with shallow draft. Journal of the Society of Naval Architects of Japan 1996. https://doi.org/10.2534/jjasnaoe1968.1998.227.
Search in Google Scholar Back to article
Fu S, Moan T, Chen X, Cui W. Hydroelastic analysis of flexible floating interconnected structures. Ocean Engineering 2007. https://doi.org/10.1016/j.oceaneng.2007.01.003.
Search in Google Scholar Back to article
Hu J, Zhou B, Vogel C, Liu P, Willden R, Sun K, Zang J, Geng J, Jin P, Cui L, Jiang B, Collu M. Optimal design and performance analysis of a hybrid system combining a floating wind platform and wave energy converters. Applied Energy 2020. https://doi.org/10.1016/j.apenergy.2020.114998.
Search in Google Scholar Back to article
Zhou B, Hu J, Jin P, Sun K, Li Y, Ning D. Power performance and motion of a floating wind platform and multiple heaving wave energy converters hybrid system. Energy 2023. https://doi.org/10.1016/j.energy.2022.126314.
Search in Google Scholar Back to article

Effects of WEC Geometry on the Performance of a WEC Array-VLFS Integrated System

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