23 Aug 2022
23 Aug 2022
Status: a revised version of this preprint is currently under review for the journal WES.

OC6 Project Phase III: Validation of the Aerodynamic Loading on a Wind Turbine Rotor Undergoing Large Motion Caused by a Floating Support Structure

Roger Bergua1, Amy Robertson1, Jason Jonkman1, Emmanuel Branlard1, Alessandro Fontanella2, Marco Belloli2, Paolo Schito2, Alberto Zasso2, Giacomo Persico3, Andrea Sanvito3, Ervin Amet4, Cédric Brun4, Guillén Campaña-Alonso5, Raquel Martín-San-Román5, Ruolin Cai6, Jifeng Cai6, Quan Qian7, Wen Maoshi7, Alec Beardsell8, Georg Pirrung9, Néstor Ramos-García9, Wei Shi10, Jie Fu10, Rémi Corniglion11, Anaïs Lovera11, Josean Galván12, Tor Anders Nygaard13, Carlos Renan dos Santos13, Philippe Gilbert14, Pierre-Antoine Joulin14, Frédéric Blondel14, Eelco Frickel15, Peng Chen16, Zhiqiang Hu16, Ronan Boisard17, Kutay Yilmazlar18, Alessandro Croce18, Violette Harnois19, Lijun Zhang20, Ye Li20, Ander Aristondo21, Iñigo Mendikoa Alonso21, Simone Mancini22, Koen Boorsma22, Feike Savenije22, David Marten23, Rodrigo Soto-Valle23, Christian Schulz24, Stefan Netzband24, Alessandro Bianchini25, Francesco Papi25, Stefano Cioni25, Pau Trubat26, Daniel Alarcon26, Climent Molins26, Marion Cormier27, Konstantin Brüker27, Thorsten Lutz27, Qing Xiao28, Zhongsheng Deng28, Florence Haudin29, and Akhilesh Goveas30 Roger Bergua et al.
  • 1National Wind Technology Center, National Renewable Energy Laboratory, Golden, CO 80401, USA
  • 2Mechanical Engineering Department, Politecnico di Milano, Milano, 20156, Italy
  • 3Laboratory of Fluid-Machines, Dipartimento di Energia, Politecnico di Milano, Milano, 20156, Italy
  • 4Wind Department, Bureau Veritas, Paris, 92937, France
  • 5Wind Turbine Technologies, Centro Nacional de Energías Renovables, Sarriguren, 31621, Spain
  • 6Integrated Simulation Department, China General Certification Center, Beijing, 100013, China
  • 7Research Institute, China State Shipbuilding Corporation, Chongqing, 401122, China
  • 8Offshore Technology Department, DNV, Bristol, BS2 0PS, UK
  • 9Department of Wind Energy, Technical University of Denmark, Lyngby, 2800, Denmark
  • 10State Key Laboratory of Coastal and Offshore Engineering, Dalian University of Technology, Dalian, 116024, China
  • 11Département Electrotechnique et Mécanique des Structures, Électricité de France, Paris, 91120, France
  • 12Wind Energy Department, eureka!, Errigoiti, 48309, Spain
  • 13Department of Wind Energy, Institute for Energy Technology, Kjeller, NO-2027, Norway
  • 14Offshore Wind and Ocean Energies, Institut Français du Pétrole Energies Nouvelles, Paris, 92852, France
  • 15Research and Development, Maritime Research Institute Netherlands, Wageningen, 6708, The Netherlands
  • 16Marine, Offshore and Subsea Technology Group, Newcastle University, Newcastle, NE1 7RU, UK
  • 17Aerodynamic Department, Office National d’Etudes et de Recherches Aérospatiales, Paris, 92190, France
  • 18Deptartment of Aerospace Science and Technology, Politecnico di Milano, Milano, 20156, Italy
  • 19Floating Offshore Group, PRINCIPIA, La Ciotat, 13600, France
  • 20Wind Energy Group, Shanghai Jiao Tong University, Shanghai, 200240, China
  • 21Department of Offshore Renewable Energy, Tecnalia Research & Innovation, Donostia-San Sebastián, 20009, Spain
  • 22Wind Energy Department, Netherlands Organisation for Applied Scientific Research, Petten, 1755, The Netherlands
  • 23Wind Energy Department, Technische Universität Berlin, Berlin, 10623, Germany
  • 24Fluid Dynamics and Ship Theory, Hamburg University of Technology, Hamburg, 21073, Germany
  • 25Department of Industrial Engineering, University of Florence, Florence, 50139, Italy
  • 26Department of Civil and Environmental Engineering, Universitat Politècnica de Catalunya, Barcelona, 08034, Spain
  • 27Wind Energy Research Group, University of Stuttgart, Stuttgart, 70569, Germany
  • 28Department of Naval Architecture, Ocean and Marine Engineering, University of Strathclyde, Glasgow, G4 0LZ, UK
  • 29Research and Development Department, Vulcain Engineering, Neuilly-sur-Seine, 92200, France
  • 30Department of Load Engineering, WyndTek, Delft, 2628, The Netherlands

Abstract. This paper provides a summary of the work done within Phase III of the Offshore Code Comparison, Collaboration, Continued, with Correlation and unCertainty project (OC6), under International Energy Agency Wind Task 30. This phase focused on validating the aerodynamic loading on a wind turbine rotor undergoing large motion caused by a floating support structure. Numerical models of the Danish Technical University 10-MW reference wind turbine were validated using measurement data from a 1:75 scale test performed during the UNsteady Aerodynamics for FLOating Wind (UNAFLOW) project and a follow-on experimental campaign, both performed at the Politecnico di Milano wind tunnel. Validation of the models was performed by comparing the loads for steady (fixed platform) and unsteady wind conditions (harmonic motion of the platform). For the unsteady wind conditions, the platform was forced to oscillate in the surge and pitch directions under several frequencies and amplitudes. These oscillations result in a wind variation that impacts the rotor loads (e.g., thrust and torque). For the conditions studied in these tests, the system mainly described a quasi-steady aerodynamic behavior. Only a small hysteresis in airfoil performance undergoing angle of attack variations in attached flow was observed. During the experiments, the rotor speed and blade pitch angle were held constant. However, in real wind turbine operating conditions, the surge and pitch variations would result in rotor speed variations and/or blade pitch actuations depending on the wind turbine controller region that the system is operating. Additional simulations with these control parameters were conducted to verify the fidelity between different models. Participant results showed in general a good agreement with the experimental measurements and the need to account for dynamic inflow when there are changes in the flow conditions due to the rotor speed variations or blade pitch actuations in response to surge and pitch motion. Numerical models not accounting for dynamic inflow effects predicted rotor loads that were 9 % lower in amplitude during rotor speed variations and 18 % higher in amplitude during blade pitch actuations.

Roger Bergua et al.

Status: final response (author comments only)

Comment types: AC – author | RC – referee | CC – community | EC – editor | CEC – chief editor | : Report abuse
  • RC1: 'Comment on wes-2022-74', Anonymous Referee #1, 19 Oct 2022
    • AC1: 'Reply on RC1', Roger Bergua Archeli, 21 Nov 2022
  • RC2: 'Comment on wes-2022-74', Vasilis A. Riziotis, 25 Oct 2022
    • AC2: 'Reply on RC2', Roger Bergua Archeli, 17 Jan 2023

Roger Bergua et al.

Roger Bergua et al.


Total article views: 1,056 (including HTML, PDF, and XML)
HTML PDF XML Total BibTeX EndNote
674 364 18 1,056 19 8
  • HTML: 674
  • PDF: 364
  • XML: 18
  • Total: 1,056
  • BibTeX: 19
  • EndNote: 8
Views and downloads (calculated since 23 Aug 2022)
Cumulative views and downloads (calculated since 23 Aug 2022)

Viewed (geographical distribution)

Total article views: 1,026 (including HTML, PDF, and XML) Thereof 1,026 with geography defined and 0 with unknown origin.
Country # Views %
  • 1
Latest update: 01 Feb 2023
Short summary
The work examines if the motion experienced by an offshore floating wind turbine can significantly affect the rotor performance. It was observed that the system motion results in variations in the load, but these variations are not critical and the current simulation tools capture the physics properly. Interestingly, variations in the rotor speed or the blade pitch angle can have a larger impact than the system motion itself.