TY - JOUR
T1 - On the Characteristics of the Wake of a Wind Turbine Undergoing Large Motions Caused by a Floating Structure: An Insight Based on Experiments and Multi-Fidelity Simulations from the OC6 Phase III Project
AU - Cioni, Stefano
AU - Papi, Francesco
AU - Pagamonci, Leonardo
AU - Bianchini, Alessandro
AU - Ramos-Garcia, Nestor
AU - Pirrung, Georg
AU - Corniglion, Remi
AU - Lovera, Anais
AU - Galvan, Josean
AU - Boisard, Ronan
AU - Fontanella, Alessandro
AU - Schito, Paolo
AU - Zasso, Alberto
AU - Belloli, Marco
AU - Sanvito, Andrea
AU - Persico, Giacomo
AU - Zhang, Lijun
AU - Li, Ye
AU - Zhou, Yarong
AU - Mancini, Simone
AU - Boorsma, Koen
AU - Amaral, Ricardo
AU - Vire, Axelle
AU - Schulz, Christian
AU - Netzband, Stefan
AU - Soto-Valle, Rodrigo
AU - Marten, David
AU - Martin-San-Roman, Raquel
AU - Trubat, Pau
AU - Molins, Climent
AU - Bergua, Roger
AU - Branlard, Emmanuel
AU - Jonkman, Jason
AU - Robertson, Amy
N1 - See NREL/JA-5000-85368 for article as published in Wind Energy Science Discussions
PY - 2023
Y1 - 2023
N2 - This study reports the results of the second round of analyses of the Offshore Code Comparison, Collaboration, Continued, with Correlation and unCertainty (OC6) project Phase III. While the first round investigated rotor aerodynamic loading, here, focus is given to the wake behavior of a floating wind turbine under large motion. Wind tunnel experimental data from the UNsteady Aerodynamics for FLOating Wind (UNAFLOW) project are compared with the results of simulations provided by participants with methods and codes of different levels of fidelity. The effect of platform motion on both the near and the far wake is investigated. More specifically, the behavior of tip vortices in the near wake is evaluated through multiple metrics, such as streamwise position, core radius, convection velocity, and circulation. Additionally, the onset of velocity oscillations in the far wake is analyzed because this can have a negative effect on stability and loading of downstream rotors. Results in the near wake for unsteady cases confirm that simulations and experiments tend to diverge from the expected linearized quasi-steady behavior when the rotor reduced frequency increases over 0.5. Additionally, differences across the simulations become significant, suggesting that further efforts are required to tune the currently available methodologies in order to correctly evaluate the aerodynamic response of a floating wind turbine in unsteady conditions. Regarding the far wake, it is seen that, in some conditions, numerical methods overpredict the impact of platform motion on the velocity fluctuations. Moreover, results suggest that the effect of platform motion on the far wake, differently from original expectations about a faster wake recovery in a floating wind turbine, seems to be limited or even oriented to the generation of a wake less prone to dissipation.
AB - This study reports the results of the second round of analyses of the Offshore Code Comparison, Collaboration, Continued, with Correlation and unCertainty (OC6) project Phase III. While the first round investigated rotor aerodynamic loading, here, focus is given to the wake behavior of a floating wind turbine under large motion. Wind tunnel experimental data from the UNsteady Aerodynamics for FLOating Wind (UNAFLOW) project are compared with the results of simulations provided by participants with methods and codes of different levels of fidelity. The effect of platform motion on both the near and the far wake is investigated. More specifically, the behavior of tip vortices in the near wake is evaluated through multiple metrics, such as streamwise position, core radius, convection velocity, and circulation. Additionally, the onset of velocity oscillations in the far wake is analyzed because this can have a negative effect on stability and loading of downstream rotors. Results in the near wake for unsteady cases confirm that simulations and experiments tend to diverge from the expected linearized quasi-steady behavior when the rotor reduced frequency increases over 0.5. Additionally, differences across the simulations become significant, suggesting that further efforts are required to tune the currently available methodologies in order to correctly evaluate the aerodynamic response of a floating wind turbine in unsteady conditions. Regarding the far wake, it is seen that, in some conditions, numerical methods overpredict the impact of platform motion on the velocity fluctuations. Moreover, results suggest that the effect of platform motion on the far wake, differently from original expectations about a faster wake recovery in a floating wind turbine, seems to be limited or even oriented to the generation of a wake less prone to dissipation.
KW - aerodynamics
KW - floating wind turbines
KW - IEA Wind Task 30
KW - OC6
KW - wind turbine wake
U2 - 10.5194/wes-8-1659-2023
DO - 10.5194/wes-8-1659-2023
M3 - Article
SN - 2366-7443
VL - 8
SP - 1659
EP - 1691
JO - Wind Energy Science
JF - Wind Energy Science
IS - 11
ER -