Abstract
The present study proposed a floating multi-body wave energy converter composed of a floating central platform, multiple oscillating bodies and multiple actuating arms. The relative motions between the oscillating bodies and the floating central platform capture multi-point wave energy simultaneously. The converter was simplified as a forced vibration system with three degrees of freedom, namely two heave motions and one rotational motion. The expressions of the amplitude-frequency response and the wave energy capture width were deduced from the motion equations of the converter. Based on the built mathematical model, the effects of the PTO damping coefficient, the PTO elastic coefficient, the connection length between the oscillating body and central platform, and the total number of oscillating bodies on the performance of the wave energy converter were investigated. Numerical results indicate that the dynamical properties and the energy conversion efficiency are related not only to the incident wave circle frequency but also to the converter's physical parameters and interior PTO coefficients. By adjusting the connection length, higher wave energy absorption efficiencies can be obtained. More oscillating bodies installed result in more stable floating central platform and higher wave energy conversion efficiency.
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References
Amiri, A., Panahi, R. and Radfar, S., 2016. Parametric study of twobody floating-point wave absorber, Journal of Marine Science and Application, 15(1), 41–49.
Budal, K. and Falnes, J., 1975. A resonant point absorber of oceanwave power, Nature, 257, 478–479.
de O Falcão, A.F., 2010. Wave energy utilization: A review of the technologies, Renewable and Sustainable Energy Reviews, 14(3), 899–918.
Evans, D.V., 1976. A theory for wave-power absorption by oscillating bodies, Journal of Fluid Mechanics, 77(1), 1–25.
Goggins, J. and Finnegan, W., 2014. Shape optimization of floating wave energy converters for a specified wave energy spectrum, Renewable Energy, 71, 208–220.
Hansen, A.H., Pedersen, H.C. and Andersen, T.O., 2014. Model based feasibility study on bidirectional check valves in wave energy converters, International Journal of Marine Energy, 5, 1–23.
Hansen, R.H., Kramer, M.M. and Vidal, E., 2013. Discrete displacement hydraulic power take-off system for the wavestar wave energy converter, Energies, 6(8), 4001–4044.
Hirohisa, T., 1982. Sea trial of a heaving buoy wave power absorber, Proceedings of 2nd International Symposium on Wave Energy Utilization, International Symposium on Wave Energy Utilization, Trondheim, Norway.
López, I., Andreu, J., Ceballos, S., de Alegría, I.M. and Kortabarria, I., 2013. Review of wave energy technologies and the necessary power-equipment, Renewable and Sustainable Energy Reviews, 27, 413–434.
McCormick, M.E., Murthagh, J. and McCabe, P., 1998. Large-scale experimental study of a hinged-barge wave energy conversion system, Proceedings of the 3rd European Wave Energy Conference, Patras, Greece, DruckTeam, Hannover.
Prado, M. and Polinder, H., 2011. Direct drive in wave energy conversion–AWS full scale prototype case study, Proceedings of 2011 IEEE Power and Energy Society General Meeting, IEEE, San Diego, CA, USA, pp. 1–7.
Prudell, J., Stoddard, M., Amon, E., Brekken, T.K.A. and von Jouanne, A., 2010. A permanent-magnet tubular linear generator for ocean wave energy conversion, IEEE Transactions on Industry Applications, 46(6), 2392–2400.
Ricci, P., 2012. Modelling, Optimization and Control of Wave Energy Point-Absorbers, Ph.D. Thesis, Lisbon University Institute, Lisbon, Portugal.
Sheng, W.A. and Lewis, A., 2016. Power takeoff optimization for maximizing energy conversion of wave-activated bodies, IEEE Journal of Oceanic Engineering, 47(3), 529–540.
Waters, R., Stâlberg, M., Danielsson, O., Svensson, O., Gustafsson, S., Strömstedt, E., Eriksson, M., Sundberg, J. and Leijon, M., 2007. Experimental results from sea trials of an offshore wave energy system, Applied Physics Letters, 90(3), 034105.
Weber, J., Mouwen, F., Parish, A. and Robertson, D., 2009. Wavebob-Research & development network and tools in the context of systems engineering, Proceedings of 8th European Wave Tidal Energy Conference, Uppsala, Sweden.
Williams, A.N., Li, W. and Wang, K.H., 2000. Water wave interaction with a floating porous cylinder, Ocean Engineering, 27(1), 1–28.
Wu, B.J., Wang, X., Diao, X.H., Peng, W. and Zhang, Y.Q., 2014. Response and conversion efficiency of two degrees of freedom wave energy device, Ocean Engineering, 76, 10–20.
Yang, S.H., He, H.Z., Chen, H., Zhang, J. and Li, H., 2016. Design and experiment research on array-raft wave energy power generation system, Journal of Mechanical Engineering, 52(11), 57–62. (in Chinese)
Zhang, W.C., Liu, H.X., Zhang, L. and Zhang, X.W., 2016. Hydrodynamic analysis and shape optimization for vertical axisymmetric wave energy converters, China Ocean Engineering, 30(6), 954–966.
Zheng, X.B., Ma, Y., Zhang, L., Jiang, J. and Liu, H.X., 2017. Experimental investigation on the hydrodynamic performance of a wave energy converter, China Ocean Engineering, 31(3), 370–377.
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Foundation item: This work was financially supported by the National Natural Science Foundation of China (Grant No. 51779104), the Natural Science Foundation of Fujian Province, China (Grant Nos. 2016J01247 and 2016J01245), the New Century Talent Support Program of Fujian Province, China (Grant No. JA13170) and the Foreign Cooperation Program of Fujian Province, China (Grant No. 2016I010003).
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Yang, Sh., Wang, Yq., He, Hz. et al. Dynamic Properties and Energy Conversion Efficiency of A Floating Multi-Body Wave Energy Converter. China Ocean Eng 32, 347–357 (2018). https://doi.org/10.1007/s13344-018-0036-7
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DOI: https://doi.org/10.1007/s13344-018-0036-7