Structural Engineering and Mechanics

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Natural frequencies and response amplitude operators of scale model of spar-type floating offshore wind turbine

  • Hong, Sin-Pyo (Global Core Research Center for Ships and Offshore Plants, Pusan National University) ;
  • Cho, Jin-Rae (Department of Naval Architecture and Ocean Engineering, Hongik University)
  • Received : 2016.03.26
  • Accepted : 2016.12.07
  • Published : 2017.03.25
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Abstract

This paper is concerned with the comparative numerical and experimental study on the natural behavior and the motion responses of a 1/75 moored scale model of a 2.5 MW spar-type floating offshore wind turbine subject to 1-D regular wave. Heave, pitch and surge motions and the mooring tensions are investigated and compared by numerical and experimental methods. The upper part of wind turbine which is composed of three rotor blades, hub and nacelle is modeled as a lumped mass and three mooring lines are pre-tensioned by means of linear springs. The numerical simulations are carried out by a coupled FEM-cable dynamics code, while the experiments are performed in a wave tank equipped with the specially-designed vision and data acquisition system. Using the both methods, the natural behavior and the motion responses in RAOs are compared and parametrically investigated to the fairlead position, the spring constant and the location of mass center of platform. It is confirmed, from the comparison, that both methods show a good agreement for all the test cases. And, it is observed that the mooring tension is influenced by all three parameters but the platform motion is dominated by the location of mass center. In addition, from the sensitivity analysis of RAOs, the coupling characteristic of platform motions and the sensitivities to the mooring parameters are investigated.

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References

  1. Aamo, O.M. and Fossen, T.I. (2000), "Finite element modeling of mooring lines", Math. Comput. Simul., 53(4-6), 415-422. https://doi.org/10.1016/S0378-4754(00)00235-4
  2. ANSYS AQWA (2012), Available from: http://www.ansys.com/products/aqwa/.
  3. Cho, J.R., Lee, H.W. and Ha, S.Y. (2005), "Finite element analysis of resonant sloshing response in 2-D baffled tank", J. Sound Vib., 288, 829-845. https://doi.org/10.1016/j.jsv.2005.01.019
  4. Choi, E.Y., Cho, J.R., Cho, Y.U., Jeong, W.B., Lee, S.B., Hong, S.P. and Chun, H.H. (2015), "Numerical and experimental study on dynamic response of moored spar-type scale platform for floating offshore wind turbine", Struct. Eng. Mech., 54(5), 909-922. https://doi.org/10.12989/sem.2015.54.5.909
  5. Colwell, S. and Basu, B. (2009), "Tuned liquid column dampers in offshore wind turbines for structural control", Eng. Struct., 31, 358-368. https://doi.org/10.1016/j.engstruct.2008.09.001
  6. Dinh, V.N., Basu, B. and Nagarajaiah, S. (2016), "Semi-active control of vibrations of spartype floating offshore wind turbines", Smart Struct. Syst., 18(4), 683-7005. https://doi.org/10.12989/sss.2016.18.4.683
  7. Dodaran, A.A. and Park, S.K. (2012), "Development of design static property analysis of mooring system caisson for offshore floating wind turbine", Int. J. Ocean Syst. Eng., 2(2), 97-105. https://doi.org/10.5574/IJOSE.2012.2.2.097
  8. Faltinsen, O.M. (1990), Sea Load on Ships and Offshore Structures, University of Cambridge.
  9. Fowler, M.J., Kimball, R.W., Thomas Iii, D.A. and Goupee, A.J. (2013), "Design and testing of scale model wind turbines for use in wind/wave basin model tests of floating offshore wind turbines", Proceedings of the ASME 2013 32nd International Conference Ocean, Offshore and Arctic Engineering, OMAE2013-10122, Nantes, France, June.
  10. Goodman, T.R. and Breslin, J.P. (1976), "Statics and dynamics of anchoring cables in waves", J. Hydronaut., 10(4), 113-120. https://doi.org/10.2514/3.63057
  11. Goopee, A.J., Koo, B.J., Lambrakos, K.F. and Kimball, R.W. (2012), "Model tests for three floating wind turbine concepts", Proceedings of the Offshore Technology Conference., Houston, USA.
  12. Jensen, J., Olsen, A. and Mansour, A. (2011), "Extreme wave and wind response predictions", Ocean Eng., 38, 2244-2253. https://doi.org/10.1016/j.oceaneng.2011.10.003
  13. Jeon, S.H., Cho, Y.U., Seo, M.W., Cho, J.R. and Jeong, W.B. (2013), "Dynamic response of floating substructure of spar-type offshore wind turbine with catenary mooring cables", Ocean Eng., 72, 356-364. https://doi.org/10.1016/j.oceaneng.2013.07.017
  14. Jonkman, J. (2009), "Dynamics of offshore floating wind turbinesmodel development and verification", Wind Energy, 12, 459-492. https://doi.org/10.1002/we.347
  15. Jonkman, J. and Musial, W. (2010), "Offshore code comparison collaboration (OC3) for IEA task 23 offshore wind technology and development", Technical Report NREL/TP-5000-48191, Colorado.
  16. Karimirad, M. (2010), "Dynamic response of floating wind turbines", Trans. B: Mech. Eng., 17(2), 146-156.
  17. Karimirad, M., Meissonnier, Q., Gao, Z. and Moan, T. (2011), "Hydroelastic code-to-code comparison for a tension leg spartype floating wind turbine", Marine Struct., 24, 412-435. https://doi.org/10.1016/j.marstruc.2011.05.006
  18. Koo, B.J., Kim, M.H. and Randall, R.E. (2004), "Mathieu instability of a spar platform with mooring and risers", Ocean Eng., 31, 2175-2208. https://doi.org/10.1016/j.oceaneng.2004.04.005
  19. Lee, H.H., Wong, S.H. and Lee, R.S. (2006), "Response mitigation on the offshore floating platform system with tuned liquid column damper", Ocean Eng., 33, 1118-1142. https://doi.org/10.1016/j.oceaneng.2005.06.008
  20. Lee, K.H. (2005), "Response of floating wind turbines to wind and wave excitation", Masters Thesis, MIT.
  21. Lee, S.H. (2008), "Dynamic response analysis of spar buoy floating wind turbine systems", Ph.D. Thesis, MIT.
  22. Loukogeorgaki, W. and Angelides, D. (2005), "Stiffness of mooring lines and performance of floating breakwater in three dimensions", Appl. Ocean Res., 27(4-5), 187-208. https://doi.org/10.1016/j.apor.2005.12.002
  23. Martin, H.R., Kimball, R.W., Viselli, A.M. and Goupee, A.J. (2012), "Methodology for wind/wave basin testing of floating offshore wind turbines", Proceedings of the ASME 2012 31st International Conference Ocean, Offshore and Arctic Engineering, OMAE2012-83627, Rio de Janeiro, Brazil, July.
  24. Morison, J.R., O'Brien, M.P., Johnson, J.W. and Schaaf, S.A. (1950), "The force exerted by surface waves on piles", Petroleum Tran., 189, 149-157.
  25. Mostafa, M., Murai, M., Nishimura, R., Fujita, O. and Nihei, Y. (2012), "Experimental validation for motion of spar-type floating wind turbine at inclination with effect of gyro moment of the rotating blade of windmill", Proceedings of the International Offshore Polar Engineering Conference, Rhodes, Greece.
  26. Newman, J.N. (1977), Marine Hydrodynamics, MIT Press, Cambridge.
  27. Patel, M.H. (1989), Dynamics of Offshore Structures, Butterworths, London.
  28. Sannasiraj, S.A., Sundar, V. and Sundaravadivelu, R. (1998), "Mooring forces and motion responses of pontoon-type floating breakwaters", Ocean Eng., 25(1), 27-48. https://doi.org/10.1016/S0029-8018(96)00044-3
  29. Shin, H. and Dam, P. (2012), "Model test of a floating offshore wind turbine moored by a spring-tensioned leg", Proceedings of the International Offshore Polar Engineering Conference, Rhodes, Greece.