0
Research Papers: Ocean Renewable Energy

Dynamic Responses of Jacket-Type Offshore Wind Turbines Using Decoupled and Coupled Models

[+] Author and Article Information
Muk Chen Ong

Professor
Department of Mechanical and Structural,
Engineering and Materials Science,
University of Stavanger (UiS),
Stavanger 4036, Norway
e-mail: muk.c.ong@uis.no

Erin E. Bachynski

Associate Professor
Department of Marine Technology,
Norwegian University of Science and
Technology (NTNU),
Trondheim 7491, Norway
e-mail: erin.bachynski@ntnu.no

Ole David Økland

Norwegian Marine Technology
Research Institute (MARINTEK),
Trondheim 7052, Norway
e-mail: Ole.Okland@marintek.sintef.no

1Corresponding author.

Contributed by the Ocean, Offshore, and Arctic Engineering Division of ASME for publication in the JOURNAL OF OFFSHORE MECHANICS AND ARCTIC ENGINEERING. Manuscript received September 9, 2016; final manuscript received January 7, 2017; published online May 5, 2017. Assoc. Editor: Yi-Hsiang Yu.

J. Offshore Mech. Arct. Eng 139(4), 041901 (May 05, 2017) (8 pages) Paper No: OMAE-16-1111; doi: 10.1115/1.4035772 History: Received September 09, 2016; Revised January 07, 2017

This paper presents numerical studies of the dynamic responses of two jacket-type offshore wind turbines (OWTs) using both decoupled and coupled models. The investigated structures are the OC4 (Offshore Code Comparison Collaboration Continuation) jacket foundation and a full-lattice support structure presented by Long et al., 2012, “Lattice Towers for Bottom-Fixed Offshore Wind Turbines in the Ultimate Limit State: Variation of Some Geo metric Parameters,” ASME J. Offshore Mech. Arct. Eng., 134(2), p. 021202. Both structures support the NREL 5-MW wind turbine. Different operational wind and wave loadings at an offshore site with relatively high soil stiffness are investigated. In the decoupled (hydroelastic) model, the thrust and torque from an isolated rotor model were used as wind loads on the decoupled model together with a linear aerodynamic damper. The coupled model is a hydro-servo-aero-elastic representation of the system. The objective of this study is to evaluate the applicability of the computationally efficient linear decoupled model by comparing with the results obtained from the nonlinear coupled model. Good agreement was obtained in the eigen-frequency analysis, decay tests, and wave-only simulations. It was also found that, by applying the thrust force from an isolated rotor model in combination with linear damping, reasonable agreement could be obtained between the decoupled and coupled models in combined wind and wave simulations.

FIGURES IN THIS ARTICLE
<>
Copyright © 2017 by ASME
Your Session has timed out. Please sign back in to continue.

References

Ormberg, H. , Fylling, I. , Larsen, K. , and Sødahl, N. , 1997, “ Coupled Analysis of Vessel Motions and Mooring and Riser System Dynamics,” Offshore Mechanics and Arctic Engineering Conference (OMAE), Yokohama, Japan, Apr. 13–17, pp. 91–100.
Moriarty, P. J. , and Hansen, A. C. , 2005, “ AeroDyn Theory Manual,” National Renewable Energy Laboratory, Golden, CO, Technical Report No. NREL/TP-500-36881.
Ormberg, H. , and Bachynski, E. E. , 2012, “ Global Analysis of Floating Wind Turbines: Code Development, Model Sensitivity and Benchmark Study,” 22nd International Offshore and Polar Engineering Conference, Rhodes, Greece, June 17–22, Vol. 1, pp. 366–373.
Karunakaran, D. , Haver, S. , Bærheim, M. , and Spidsøe, N. , 2001, “ Dynamic Behaviour of the Kvitebjørn Jacket in the North Sea,” 20th International Conference on Offshore Mechanics and Arctic Engineering, Rio de Janeiro, Brazil, Paper No. OMAE01/OFT-1184.
Vorpahl, F. , Kaufer, D. , and Popko, W. , 2011, “ Description of a Basic Model of the “UpWind Reference Jacket” for Code Comparison in the OC4 Project Under IEA Wind Annex 30,” Technical Report, Fraunhofer Institute for Wind Energy and Energy System Technology IWES, Bremerhaven, Germany.
Jonkman, J. , Butterfield, S. , Musial, W. , and Scott, G. , 2009, “ Definition of a 5-MW Reference Wind Turbine for Offshore System Development,” National Renewable Energy Laboratory, Golden, CO, Technical Report No. NREL/TP-500-38060.
Long, H. , Moe, G. , and Fischer, T. , 2012, “ Lattice Towers for Bottom-Fixed Offshore Wind Turbines in the Ultimate Limit State: Variation of Some Geometric Parameters,” ASME J. Offshore Mech. Arct. Eng., 134(2), p. 021202. [CrossRef]
Vemula, N. K. , DeVries, W. , Fischer, T. , and Schmidt, B. , 2010, “ Design Solution for the UpWind Reference Offshore Support Structure,” Technical Report, Upwind Deliverable D4.2.6 (WP4: Offshore Foundations and Support Structures), Rambøll Wind Energy, Esbjerg, Denmark.
Long, H. , 2013, personal communication by email.
Ong, M. C. , Li, H. , Leira, B. J. , and Myrhaug, D. , 2013, “ Dynamic Analysis of Offshore Monopile Wind Turbine Including the Effects of Wind-Wave Loading and Soil Properties,” 32nd International Conference on Ocean, Offshore and Arctic Engineering, Nantes, France, Paper No. OMAE2013-10527.
Salzmann, D. J. C. , and van der Tempel, J. , 2005, “ Aerodynamic Damping in the Design of Support Structures for Offshore Wind Turbines,” Offshore Wind Energy Conference, Copenhagen, Denmark, pp. 1–9.
Bachynski, E. E. , 2014, “ Design and Dynamic Analysis of Tension Leg Platform Wind Turbines,” Ph.D. thesis, Norwegian University of Science and Technology, Trondheim, Norway.
Kvittem, M. I. , 2014, “ Modelling and Response Analysis for Fatigue Design of a Semi-Submersible Wind Turbine,” Ph.D. thesis, Norwegian University of Science and Technology, Trondheim, Norway.
Popko, W. , Vorpahl, F. , Zuga, A. , Kohlmeier, M. , Jonkman, J. , Robertson, A. , Larsen, T. J. , and Yde, A. , 2012, “ Offshore Code Comparison Collaboration Continuation (OC4), Phase I: Results of Coupled Simulations of an Offshore Wind Turbine With Jacket Support Structure,” 22nd International Society of Offshore and Polar Engineers Conference, Rhodes, Greece, June 17–22, Vol. 1, pp. 337–348.

Figures

Grahic Jump Location
Fig. 1

OC4 jacket OWT, modeled in SIMA

Grahic Jump Location
Fig. 2

Full-lattice OWT, modeled in SIMA

Grahic Jump Location
Fig. 3

Global coordinate system at the tower top

Grahic Jump Location
Fig. 4

Configuration of the decoupling method

Grahic Jump Location
Fig. 5

Decay test with OC4 jacket OWT. Tower top fore-aft displacement is shown.

Grahic Jump Location
Fig. 6

Time series of the axial force in element 1 of the OC4 jacket for EC4, wave-only

Grahic Jump Location
Fig. 7

Spectrum of the axial force in element 1 of the OC4 jacket for EC4, wave-only

Grahic Jump Location
Fig. 8

Time series of the axial force in element 1 of the full-lattice jacket for EC4, wave-only

Grahic Jump Location
Fig. 9

Spectrum of the axial force in element 1 of the full-lattice jacket for EC4, wave-only

Grahic Jump Location
Fig. 10

Time-series plots of the displacement of the tower top in x-direction, the axial force in element 1, and the tower base moment for the OC4 jacket in EC2, combined wind and waves

Grahic Jump Location
Fig. 11

Spectra of the displacement of the tower top in x-direction, the axial force in element 1, and the tower base moment for the OC4 jacket in EC2, combined wind and waves

Grahic Jump Location
Fig. 12

Spectra of the displacement of the tower top in x-direction, the axial force in element 1, and the tower base moment for the OC4 jacket in EC4, combined wind and waves

Grahic Jump Location
Fig. 13

Spectra of the tower top displacement and the axial forces in lines 1 and 2, lattice, EC2, combined wind and wave

Grahic Jump Location
Fig. 14

Spectra of the tower top displacement and the axial forces in lines 1 and 2, lattice, EC4, combined wind and wave

Tables

Errata

Discussions

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In