Abstract
In intermediate water depths (100–300 m), an array of floating point-absorbing Wave Energy Converters (WECs) may be employed for extracting efficiently ocean wave energy. In such case, it may be more feasible and convenient to connect the absorbers array with a semi-submersible bottom-moored platform, whose function is to act as the seabed. An array of identical floating symmetrically distributed cylinders in a coaxial moored platform is proposed in this study. The Power Take-Off (PTO) system is assumed to be composed of a linear/nonlinear damper activated by the buoys heaving motion. Linear hydrodynamic analysis of the examined floating system is implemented in frequency domain. Hydrodynamic interferences between the oscillating bodies are accounted for in the corresponding coupled equations. The array layouts under the constraint of the platform, incidence wave directions, separating distance between the absorbers and the PTO damping are considered to optimize this kind of WECs. Numerical results with regular waves are presented and discussed for the axisymmetric system utilizing heave mode with these impact factors, in terms of a specific numbers of cylinders and expected power production.
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References
Evans DV (1976) A theory for wave-power absorption by oscillating bodies. J Fluid Mech 77(1):1–25
Falnes J (2002). Linear interaction including wave-energy extraction. Ocean waves and oscillating system. Cambridge University press
Eriksson M, Isberg J, Leijon M (2005) Hydrodynamic modelling of a direct drive wave energy converter. Int J Eng Sci 43(s 17–18):1377–1387
Fitzgerald J, Bergdahl L (2008) Including moorings in the assessment of a generic offshore wave energy converter: a frequency domain approach. Mar Struct 21(1):23–46
Price AAE, Dent CJ, Wallace AR (2009) On the capture width of wave energy converters. Appl Ocean Res 31(4):251–259
Sheng WN, Alcorn R, Lewis A (2015). Optimising power take-offs for maximizing wave energy conversions. In: The 30th International Workshop on Water Waves and Floating Bodies, Bristol, UK
Sheng WN, Lewis A (2016) Power take off optimization for maximizing energy conversion of wave-activated bodies. IEEE J Ocean Eng 1–12
Budal K (1977) Theory for absorption of wave power by a system of interacting bodies. J Ship Res 21:248–253
Falnes J, Budal K (1982) Wave-power absorption by parallel rows of interacting oscillating bodies. Appl Ocean Res 4:194–207
McIver P (1994) Some hydrodynamic aspects of arrays of wave energy devices. Appl Ocean Res 19:283–291
Fitzgerald C, Thomas G (2007) A preliminary study on the optimal formation of an array of wave power devices. In: Proceedings of the 7th European Wave and Tidal Energy Conference, Porto, Portugal
Garnaud X, Mei CC (2010). Comparison of wave power extraction by a compact array of small buoys and by a large buoy. IET Renew Power Gener 4 (6):519–530
Borgarino B, Babarit A, Ferrant P (2012). Impact of wave interactions effects on energy absorption in large arrays of wave energy converters. Ocean Eng 41:79–88
Wolgamot HA, Taylor PH, Taylor RE (2012) The interaction factor and directionality in wave energy arrays. Ocean Eng 47:65–73
Heikkinen H, Lampinen MJ, Boling J (2013) Analytical study of the interaction between waves and cylindrical wave energy converters oscillating in two modes. Renew Energy 50:150–160
Sharkey F, Bannon E, Conlon M, Gaughan K (2013) Maximising value of electrical networks for wave energy converter arrays. Int J Mar Energy 1:55–69
Goteman M, Engstrom J, Eriksson M, Isberg J, Leijon M (2014) Analytical and numerical approaches to optimizing fluid-structure interactions in wave energy parks. Iwwwfb.naoe.eng.osaka.
Goteman M, Engstrom J, Eriksson M, Isberg J, Leijon M (2014) Methods of reducing power fluctuations in wave energy parks. J Renew Sustain Energy 6:043103
Weller SD, Stallard TJ, Stansby PK (2010) Experimental measurements of irregular wave interaction factors in closely spaced arrays. IET Renew Power Gener 4 (6):628–637
Child BFM, Venugopal V (2010) Optimal configurations of wave energy device arrays. Ocean Eng 37:1402–1417
Babarit A (2010) Impact of long separating distances on the energy production of two interacting wave energy converters. Ocean Eng 37:718–729
Andres AD, Guanche R, Meneses L, Vidal C, Losada IJ (2014). Factors that influence array layout on wave energy farms. Ocean Eng 82:32–41
Goteman M, Engstrom J, Eriksson M, Isberg J (2015) Optimizing wave energy parks with over 1000 interacting point-absorbers using an approximate analytical method. Int J Mar Energy 10:113–126
Koh HJ, Ruy WS et al (2014) Multi-objective optimum design of a buoy for the resonant-type wave energy converter. J Mar Sci Technol 20(1):53–63
Acknowledgements
This paper is financially supported by the National Natural Science Foundation (No. 11572094, No. 51579055 and No. 51509048) and High-tech Ship Research Projects-Floating Support Platform Sponsored by the Ministry of Industry and Information Technology (MIIT) of China.
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Liu, H.X., Zhang, W.C., Zheng, X.B. et al. Wave energy conversion by cylinder array with a floating platform considering linear/nonlinear PTO damping. J Mar Sci Technol 22, 747–757 (2017). https://doi.org/10.1007/s00773-017-0441-2
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DOI: https://doi.org/10.1007/s00773-017-0441-2