Abstract
Technologies for harvesting offshore renewable energy based on floating platforms, such as offshore wind, wave and tidal energies, are currently being developed with the purpose of achieving a competitive cost of energy. The economic impact of the mooring system is significant within the total cost of such deployments, and large efforts are being carried out to optimize designs. Analysis of mooring systems at early stages generally require a trade-off between quick analysis methods and accuracy to carry out multi-variate sensitivity analyses. Even though the most accurate approaches are based on the non-linear finite element method in the time domain, these can result in being very time consuming.
The most widely used numerical approaches for mooring line load estimates are introduced and discussed in this paper. It is verified that accurate line tension estimates require lines drag and inertia forces to be accounted for. A mooring and floating structure coupled model based on the lumped mass finite element approach is also discussed, and it is confirmed that the differences found in the coupled numerical model are mainly produced by the uncertainty on hydrodynamic force estimates on the floating structure rather than by the lumped mass method. In order to enable quick line tension estimates, a linearization of the structure and mooring coupled model is discussed. It shows accurate results in operational conditions and enables modal analysis of the coupled system.
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References
MARMOK-A-5 Wave Energy ConverterāTethys. https://tethys.pnnl.gov/project-sites/marmok-5-wave-energy-converter
http://www.corpowerocean.com/technology/. http://www.corpowerocean.com/technology/
Ireland leads the way in ocean energy as SEAI funded wave energy device arrives in Hawaii for testing. Sustainable Energy Authority of Ireland. https://www.seai.ie/news-and-media/ocean-energy-test-device/
OESāNewsāInternational LCOE for Ocean Energy Technology. https://www.ocean-energy-systems.org/news/international-lcoe-for-ocean-energy-technology/
Muliawan, M.J., Karimirad, M., Gao, Z., Moan, T.: Extreme responses of a combined spar-type floating wind turbine and floating wave energy converter (STC) system with survival modes. Ocean Eng. 65, 71ā82 (2013)
Van den Boom, H.J.J.: Dynamic behaviour of mooring lines. Behav. Offsh. Struct. Elsevier Sci. Publ. B V 359ā368 (1985)
Azcona, J., Munduate, X., GonzĆ”lez, L., Nygaard, T.A.: Experimental validation of a dynamic mooring lines code with tension and motion measurements of a submerged chain. Ocean Eng. 129, 415ā427 (2017)
Hall, M., Goupee, A.: Validation of a lumped-mass mooring line model with DeepCwind semisubmersible model test data. Ocean Eng. 104, 590ā603 (2015)
Touzon, I., Nava, V., Gao, Z., Mendikoa, I., Petuya, V.: Small scale experimental validation of a numerical model of the HarshLab2.0 floating platform coupled with a non-linear lumped mass catenary mooring system. Ocean Eng. 200, 107036 (2020)
Touzon, I., et al.: Mooring system design approach: a case study for MARMOK-a floating OWC wave energy converter. In: American Society of Mechanical Engineers Digital Collection (2018). https://doi.org/10.1115/OMAE2018-77634
DNVGL-OS-E301: Position mooring (2018). http://rules.dnvgl.com/docs/pdf/dnvgl/os/2018-07/dnvgl-os-e301.pdf
Touzon, I., Nava, V., de Miguel, B., Petuya, V.: A comparison of numerical approaches for the design of mooring systems for wave energy converters. J. Mar. Sci. Eng. 8, 523 (2020)
Offshore Renewable Energy, Committee v.4. in Proceedings of the 20th International Ship and Offshore Structures Congress (ISSC 2018) (Ed. by, International Ship & Offshore Structures Congress, Kaminski, M.L., Rigo, P., IOS Press) (2018). https://doi.org/10.3233/978-1-61499-864-8-193
Garcia De Jalon, J., Bayo, E.: Kinematic and Dynamic Simulation of Multibody Systems: The Realtime Challenge. Springer, New York (1994). https://doi.org/10.1007/978-1-4612-2600-0
Pinkster, J.A., Basin, N.S.M.: Low frequency second order wave exciting forces on floating structures, 220 (1980)
Cummins, W.E.: The impulse response function and ship motions (1962)
NI 461 DTO R00 E - Quasi-Dynamic Analysis of Mooring Systems using Ariane Software (1997)
Duclos, G., Clement, A.H., Chatry, G.: Absorption of outgoing waves in a numerical wave tank using a self-adaptive boundary condition. Int. J. Offsh. Polar Eng. 11, 168ā175 (2001)
Perez, T., Fossen, T.I.: Time-domain vs. frequency-domain identification of parametric radiation force models for marine structures at zero speed. Identification Control, 19 (2008)
DNV-RP-C205: Environmental Conditions and Environmental Loads, 124 (2010)
Naess, A., Moan, T.: Stochastic Dynamics of Marine Structures. Cambridge University Press, Cambridge (2012). https://doi.org/10.1017/CBO9781139021364
Low, Y.M., Langley, R.S.: Time and frequency domain coupled analysis of deepwater floating production systems. Appl. Ocean Res. 28, 371ā385 (2006)
Touzon, I., Nava, V., Gao, Z., Petuya, V.: Frequency domain modelling of a coupled system of floating structure and mooring Lines: an application to a wave energy converter. Ocean Eng. 220, 108498 (2021)
Acknowledgments
This work was funded by Project IT949-16 (Departamento de EducaciĆ³n, PolĆtica LingĆ¼Ćstica y Cultura, Regional). Government of the Basque Country.
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Touzon, I., Petuya, V., Nava, V., Alonso-Reig, M., Mendikoa, I. (2022). Numerical Approaches for Loads and Motions Assessment of Floating WECs Moored by Means of Catenary Mooring Systems. In: Quaglia, G., Gasparetto, A., Petuya, V., Carbone, G. (eds) Proceedings of I4SDG Workshop 2021. I4SDG 2021. Mechanisms and Machine Science, vol 108. Springer, Cham. https://doi.org/10.1007/978-3-030-87383-7_7
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