Articles | Volume 7, issue 6
https://doi.org/10.5194/wes-7-2201-2022
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/wes-7-2201-2022
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
07 Nov 2022
Research article |
| 07 Nov 2022
| 07 Nov 2022
Multiple limit cycle amplitudes in high-fidelity predictions of standstill wind turbine blade vibrations
Department of Wind Energy, Technical University of Denmark, Risø Campus, 4000, Roskilde, Denmark
Niels Nørmark Sørensen
Department of Wind Energy, Technical University of Denmark, Risø Campus, 4000, Roskilde, Denmark
Georg Raimund Pirrung
Department of Wind Energy, Technical University of Denmark, Risø Campus, 4000, Roskilde, Denmark
Sergio González Horcas
Department of Wind Energy, Technical University of Denmark, Risø Campus, 4000, Roskilde, Denmark
Related authors
Christian Grinderslev, Felix Houtin-Mongrolle, Niels Nørmark Sørensen, Georg Raimund Pirrung, Pim Jacobs, Aqeel Ahmed, and Bastien Duboc
Wind Energ. Sci., 8, 1625–1638, https://doi.org/10.5194/wes-8-1625-2023, https://doi.org/10.5194/wes-8-1625-2023, 2023
Short summary
Short summary
In standstill conditions wind turbines are at risk of vortex-induced vibrations (VIVs). VIVs can become large and lead to significant fatigue of the wind turbine structure over time. Thus it is important to have tools that can accurately compute this complex phenomenon. This paper studies the sensitivities to the chosen models of computational fluid dynamics (CFD) simulations when modelling VIVs and finds that much care is needed when setting up simulations, especially for specific flow angles.
Koen Boorsma, Gerard Schepers, Helge Aagard Madsen, Georg Pirrung, Niels Sørensen, Galih Bangga, Manfred Imiela, Christian Grinderslev, Alexander Meyer Forsting, Wen Zhong Shen, Alessandro Croce, Stefano Cacciola, Alois Peter Schaffarczyk, Brandon Lobo, Frederic Blondel, Philippe Gilbert, Ronan Boisard, Leo Höning, Luca Greco, Claudio Testa, Emmanuel Branlard, Jason Jonkman, and Ganesh Vijayakumar
Wind Energ. Sci., 8, 211–230, https://doi.org/10.5194/wes-8-211-2023, https://doi.org/10.5194/wes-8-211-2023, 2023
Short summary
Short summary
Within the framework of the fourth phase of the International Energy Agency's (IEA) Wind Task 29, a large comparison exercise between measurements and aeroelastic simulations has been carried out. Results were obtained from more than 19 simulation tools of various fidelity, originating from 12 institutes and compared to state-of-the-art field measurements. The result is a unique insight into the current status and accuracy of rotor aerodynamic modeling.
Christian Grinderslev, Niels Nørmark Sørensen, Sergio González Horcas, Niels Troldborg, and Frederik Zahle
Wind Energ. Sci., 6, 627–643, https://doi.org/10.5194/wes-6-627-2021, https://doi.org/10.5194/wes-6-627-2021, 2021
Short summary
Short summary
This study investigates aero-elasticity of wind turbines present in the turbulent and chaotic wind flow of the lower atmosphere, using fluid–structure interaction simulations. This method combines structural response computations with high-fidelity modeling of the turbulent wind flow, using a novel turbulence model which combines the capabilities of large-eddy simulations for atmospheric flows with improved delayed detached eddy simulations for the separated flow near the rotor.
Christian Grinderslev, Federico Belloni, Sergio González Horcas, and Niels Nørmark Sørensen
Wind Energ. Sci., 5, 543–560, https://doi.org/10.5194/wes-5-543-2020, https://doi.org/10.5194/wes-5-543-2020, 2020
Short summary
Short summary
This study focuses on coupled computational fluid and structural dynamics simulations of a dynamic structural test of a wind turbine blade, as performed in laboratories. It is found that drag coefficients used for simulations, when planning fatigue tests, underestimate air resistance to the dynamic motion that the blade undergoes during tests. If this is not corrected for, this can result in the forces applied to the blade actually being lower in reality during tests than what was planned.
Stefano Cioni, Francesco Papi, Leonardo Pagamonci, Alessandro Bianchini, Néstor Ramos-García, Georg Pirrung, Rémi Corniglion, Anaïs Lovera, Josean Galván, Ronan Boisard, Alessandro Fontanella, Paolo Schito, Alberto Zasso, Marco Belloli, Andrea Sanvito, Giacomo Persico, Lijun Zhang, Ye Li, Yarong Zhou, Simone Mancini, Koen Boorsma, Ricardo Amaral, Axelle Viré, Christian W. Schulz, Stefan Netzband, Rodrigo Soto-Valle, David Marten, Raquel Martín-San-Román, Pau Trubat, Climent Molins, Roger Bergua, Emmanuel Branlard, Jason Jonkman, and Amy Robertson
Wind Energ. Sci., 8, 1659–1691, https://doi.org/10.5194/wes-8-1659-2023, https://doi.org/10.5194/wes-8-1659-2023, 2023
Short summary
Short summary
Simulations of different fidelities made by the participants of the OC6 project Phase III are compared to wind tunnel wake measurements on a floating wind turbine. Results in the near wake confirm that simulations and experiments tend to diverge from the expected linearized quasi-steady behavior when the reduced frequency exceeds 0.5. In the far wake, the impact of platform motion is overestimated by simulations and even seems to be oriented to the generation of a wake less prone to dissipation.
Christian Grinderslev, Felix Houtin-Mongrolle, Niels Nørmark Sørensen, Georg Raimund Pirrung, Pim Jacobs, Aqeel Ahmed, and Bastien Duboc
Wind Energ. Sci., 8, 1625–1638, https://doi.org/10.5194/wes-8-1625-2023, https://doi.org/10.5194/wes-8-1625-2023, 2023
Short summary
Short summary
In standstill conditions wind turbines are at risk of vortex-induced vibrations (VIVs). VIVs can become large and lead to significant fatigue of the wind turbine structure over time. Thus it is important to have tools that can accurately compute this complex phenomenon. This paper studies the sensitivities to the chosen models of computational fluid dynamics (CFD) simulations when modelling VIVs and finds that much care is needed when setting up simulations, especially for specific flow angles.
Paul Veers, Carlo L. Bottasso, Lance Manuel, Jonathan Naughton, Lucy Pao, Joshua Paquette, Amy Robertson, Michael Robinson, Shreyas Ananthan, Thanasis Barlas, Alessandro Bianchini, Henrik Bredmose, Sergio González Horcas, Jonathan Keller, Helge Aagaard Madsen, James Manwell, Patrick Moriarty, Stephen Nolet, and Jennifer Rinker
Wind Energ. Sci., 8, 1071–1131, https://doi.org/10.5194/wes-8-1071-2023, https://doi.org/10.5194/wes-8-1071-2023, 2023
Short summary
Short summary
Critical unknowns in the design, manufacturing, and operation of future wind turbine and wind plant systems are articulated, and key research activities are recommended.
Maarten Paul van der Laan, Oscar García-Santiago, Mark Kelly, Alexander Meyer Forsting, Camille Dubreuil-Boisclair, Knut Sponheim Seim, Marc Imberger, Alfredo Peña, Niels Nørmark Sørensen, and Pierre-Elouan Réthoré
Wind Energ. Sci., 8, 819–848, https://doi.org/10.5194/wes-8-819-2023, https://doi.org/10.5194/wes-8-819-2023, 2023
Short summary
Short summary
Offshore wind farms are more commonly installed in wind farm clusters, where wind farm interaction can lead to energy losses. In this work, an efficient numerical method is presented that can be used to estimate these energy losses. The novel method is verified with higher-fidelity numerical models and validated with measurements of an existing wind farm cluster.
Roger Bergua, Amy Robertson, Jason Jonkman, Emmanuel Branlard, Alessandro Fontanella, Marco Belloli, Paolo Schito, Alberto Zasso, Giacomo Persico, Andrea Sanvito, Ervin Amet, Cédric Brun, Guillén Campaña-Alonso, Raquel Martín-San-Román, Ruolin Cai, Jifeng Cai, Quan Qian, Wen Maoshi, Alec Beardsell, Georg Pirrung, Néstor Ramos-García, Wei Shi, Jie Fu, Rémi Corniglion, Anaïs Lovera, Josean Galván, Tor Anders Nygaard, Carlos Renan dos Santos, Philippe Gilbert, Pierre-Antoine Joulin, Frédéric Blondel, Eelco Frickel, Peng Chen, Zhiqiang Hu, Ronan Boisard, Kutay Yilmazlar, Alessandro Croce, Violette Harnois, Lijun Zhang, Ye Li, Ander Aristondo, Iñigo Mendikoa Alonso, Simone Mancini, Koen Boorsma, Feike Savenije, David Marten, Rodrigo Soto-Valle, Christian W. Schulz, Stefan Netzband, Alessandro Bianchini, Francesco Papi, Stefano Cioni, Pau Trubat, Daniel Alarcon, Climent Molins, Marion Cormier, Konstantin Brüker, Thorsten Lutz, Qing Xiao, Zhongsheng Deng, Florence Haudin, and Akhilesh Goveas
Wind Energ. Sci., 8, 465–485, https://doi.org/10.5194/wes-8-465-2023, https://doi.org/10.5194/wes-8-465-2023, 2023
Short summary
Short summary
This 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.
Brandon Arthur Lobo, Özge Sinem Özçakmak, Helge Aagaard Madsen, Alois Peter Schaffarczyk, Michael Breuer, and Niels N. Sørensen
Wind Energ. Sci., 8, 303–326, https://doi.org/10.5194/wes-8-303-2023, https://doi.org/10.5194/wes-8-303-2023, 2023
Short summary
Short summary
Results from the DAN-AERO and aerodynamic glove projects provide significant findings. The effects of inflow turbulence on transition and wind turbine blades are compared to computational fluid dynamic simulations. It is found that the transition scenario changes even over a single revolution. The importance of a suitable choice of amplification factor is evident from the simulations. An agreement between the power spectral density plots from the experiment and large-eddy simulations is seen.
Koen Boorsma, Gerard Schepers, Helge Aagard Madsen, Georg Pirrung, Niels Sørensen, Galih Bangga, Manfred Imiela, Christian Grinderslev, Alexander Meyer Forsting, Wen Zhong Shen, Alessandro Croce, Stefano Cacciola, Alois Peter Schaffarczyk, Brandon Lobo, Frederic Blondel, Philippe Gilbert, Ronan Boisard, Leo Höning, Luca Greco, Claudio Testa, Emmanuel Branlard, Jason Jonkman, and Ganesh Vijayakumar
Wind Energ. Sci., 8, 211–230, https://doi.org/10.5194/wes-8-211-2023, https://doi.org/10.5194/wes-8-211-2023, 2023
Short summary
Short summary
Within the framework of the fourth phase of the International Energy Agency's (IEA) Wind Task 29, a large comparison exercise between measurements and aeroelastic simulations has been carried out. Results were obtained from more than 19 simulation tools of various fidelity, originating from 12 institutes and compared to state-of-the-art field measurements. The result is a unique insight into the current status and accuracy of rotor aerodynamic modeling.
Thanasis Barlas, Georg Raimund Pirrung, Néstor Ramos-García, Sergio González Horcas, Ang Li, and Helge Aagaard Madsen
Wind Energ. Sci., 7, 1957–1973, https://doi.org/10.5194/wes-7-1957-2022, https://doi.org/10.5194/wes-7-1957-2022, 2022
Short summary
Short summary
An aeroelastically optimized curved wind turbine blade tip is designed, manufactured, and tested on a novel outdoor rotating rig facility at the Risø campus of the Technical University of Denmark. Detailed aerodynamic measurements for various atmospheric conditions and results are compared to a series of in-house aeroelastic tools with a range of fidelities in aerodynamic modeling. The comparison highlights details in the ability of the codes to predict the performance of such a curved tip.
Mads H. Aa. Madsen, Frederik Zahle, Sergio González Horcas, Thanasis K. Barlas, and Niels N. Sørensen
Wind Energ. Sci., 7, 1471–1501, https://doi.org/10.5194/wes-7-1471-2022, https://doi.org/10.5194/wes-7-1471-2022, 2022
Short summary
Short summary
This work presents a shape optimization framework based on computational fluid dynamics. The design framework is used to optimize wind turbine blade tips for maximum power increase while avoiding that extra loading is incurred. The final results are shown to align well with related literature. The resulting tip shape could be mounted on already installed wind turbines as a sleeve-like solution or be conceived as part of a modular blade with tips designed for site-specific conditions.
Ang Li, Mac Gaunaa, Georg Raimund Pirrung, Alexander Meyer Forsting, and Sergio González Horcas
Wind Energ. Sci., 7, 1341–1365, https://doi.org/10.5194/wes-7-1341-2022, https://doi.org/10.5194/wes-7-1341-2022, 2022
Short summary
Short summary
A consistent method of using two-dimensional airfoil data when using generalized lifting-line methods for the aerodynamic load calculation of non-planar horizontal-axis wind turbines is described. The important conclusions from the unsteady two-dimensional airfoil aerodynamics are highlighted. The impact of using a simplified approach instead of using the full model on the prediction of the aerodynamic performance of non-planar rotors is shown numerically for different aerodynamic models.
Ang Li, Georg Raimund Pirrung, Mac Gaunaa, Helge Aagaard Madsen, and Sergio González Horcas
Wind Energ. Sci., 7, 129–160, https://doi.org/10.5194/wes-7-129-2022, https://doi.org/10.5194/wes-7-129-2022, 2022
Short summary
Short summary
An engineering aerodynamic model for the swept horizontal-axis wind turbine blades is proposed. It uses a combination of analytical results and engineering approximations. The performance of the model is comparable with heavier high-fidelity models but has similarly low computational cost as currently used low-fidelity models. The model could be used for an efficient and accurate load calculation of swept wind turbine blades and could eventually be integrated in a design optimization framework.
Ang Li, Mac Gaunaa, Georg Raimund Pirrung, and Sergio González Horcas
Wind Energ. Sci., 7, 75–104, https://doi.org/10.5194/wes-7-75-2022, https://doi.org/10.5194/wes-7-75-2022, 2022
Short summary
Short summary
An engineering aerodynamic model for non-planar horizontal-axis wind turbines is proposed. The performance of the model is comparable with high-fidelity models but has similarly low computational cost as currently used low-fidelity models, which do not have the capability to model non-planar rotors. The developed model could be used for an efficient and accurate load calculation of non-planar wind turbines and eventually be integrated in a design optimization framework.
Thanasis Barlas, Georg Raimund Pirrung, Néstor Ramos-García, Sergio González Horcas, Robert Flemming Mikkelsen, Anders Smærup Olsen, and Mac Gaunaa
Wind Energ. Sci., 6, 1311–1324, https://doi.org/10.5194/wes-6-1311-2021, https://doi.org/10.5194/wes-6-1311-2021, 2021
Short summary
Short summary
Curved blade tips can potentially have a significant impact on wind turbine performance and loads. A swept tip shape optimized for wind turbine applications is tested in a wind tunnel. A range of numerical aerodynamic simulation tools with various levels of fidelity are compared. We show that all numerical tools except for the simplest blade element momentum based are in good agreement with the measurements, suggesting the required level of model fidelity necessary for the design of such tips.
Thales Fava, Mikaela Lokatt, Niels Sørensen, Frederik Zahle, Ardeshir Hanifi, and Dan Henningson
Wind Energ. Sci., 6, 715–736, https://doi.org/10.5194/wes-6-715-2021, https://doi.org/10.5194/wes-6-715-2021, 2021
Short summary
Short summary
This work develops a simplified framework to predict transition to turbulence on wind-turbine blades. The model is based on the boundary-layer and parabolized stability equations, including rotation and three-dimensionality effects. We show that these effects may promote transition through highly oblique Tollmien–Schlichting (TS) or crossflow modes at low radii, and they should be considered for a correct transition prediction. At high radii, transition tends to occur through 2D TS modes.
Christian Grinderslev, Niels Nørmark Sørensen, Sergio González Horcas, Niels Troldborg, and Frederik Zahle
Wind Energ. Sci., 6, 627–643, https://doi.org/10.5194/wes-6-627-2021, https://doi.org/10.5194/wes-6-627-2021, 2021
Short summary
Short summary
This study investigates aero-elasticity of wind turbines present in the turbulent and chaotic wind flow of the lower atmosphere, using fluid–structure interaction simulations. This method combines structural response computations with high-fidelity modeling of the turbulent wind flow, using a novel turbulence model which combines the capabilities of large-eddy simulations for atmospheric flows with improved delayed detached eddy simulations for the separated flow near the rotor.
Thanasis Barlas, Néstor Ramos-García, Georg Raimund Pirrung, and Sergio González Horcas
Wind Energ. Sci., 6, 491–504, https://doi.org/10.5194/wes-6-491-2021, https://doi.org/10.5194/wes-6-491-2021, 2021
Short summary
Short summary
A method to design advanced tip extensions for modern wind turbine blades is presented in this work. The resulting design concept has high potential in terms of actual implementation in a real rotor upscaling with a potential business case in reducing the cost of energy produced by future large wind turbine rotors.
Özge Sinem Özçakmak, Helge Aagaard Madsen, Niels Nørmark Sørensen, and Jens Nørkær Sørensen
Wind Energ. Sci., 5, 1487–1505, https://doi.org/10.5194/wes-5-1487-2020, https://doi.org/10.5194/wes-5-1487-2020, 2020
Short summary
Short summary
Accurate prediction of the laminar-turbulent transition process is critical for design and prediction tools to be used in the industrial design process, particularly for the high Reynolds numbers experienced by modern wind turbines. Laminar-turbulent transition behavior of a wind turbine blade section is investigated in this study by means of field experiments and 3-D computational fluid dynamics (CFD) rotor simulations.
Christian Grinderslev, Federico Belloni, Sergio González Horcas, and Niels Nørmark Sørensen
Wind Energ. Sci., 5, 543–560, https://doi.org/10.5194/wes-5-543-2020, https://doi.org/10.5194/wes-5-543-2020, 2020
Short summary
Short summary
This study focuses on coupled computational fluid and structural dynamics simulations of a dynamic structural test of a wind turbine blade, as performed in laboratories. It is found that drag coefficients used for simulations, when planning fatigue tests, underestimate air resistance to the dynamic motion that the blade undergoes during tests. If this is not corrected for, this can result in the forces applied to the blade actually being lower in reality during tests than what was planned.
Alexander R. Meyer Forsting, Georg R. Pirrung, and Néstor Ramos-García
Wind Energ. Sci., 5, 349–353, https://doi.org/10.5194/wes-5-349-2020, https://doi.org/10.5194/wes-5-349-2020, 2020
Short summary
Short summary
Simulations of wind farms allow the estimation of the forces acting on the turbines and thus their lifetime and power production. Representing the actual geometric shape of turbines in a realistic atmospheric flow is computationally expensive; therefore they are modelled in a simplified manner. Unfortunately, these simplifications negatively impact the estimated forces. We developed an open-source aerodynamic model that corrects the forces, giving more accurate estimates of lifetime and power.
Helge Aagaard Madsen, Torben Juul Larsen, Georg Raimund Pirrung, Ang Li, and Frederik Zahle
Wind Energ. Sci., 5, 1–27, https://doi.org/10.5194/wes-5-1-2020, https://doi.org/10.5194/wes-5-1-2020, 2020
Short summary
Short summary
We show in the paper that the upscaling of turbines has led to new requirements in simulation of the unsteady aerodynamic forces by the engineering blade element momentum (BEM) model, originally developed for simulation of the aerodynamics of propellers and helicopters. We present a new implementation of the BEM model on a polar grid which can be characterized as an engineering actuator disc model. The aeroelastic load impact of the new BEM implementation is analyzed and quantified.
Alexander R. Meyer Forsting, Georg Raimund Pirrung, and Néstor Ramos-García
Wind Energ. Sci., 4, 369–383, https://doi.org/10.5194/wes-4-369-2019, https://doi.org/10.5194/wes-4-369-2019, 2019
Short summary
Short summary
The actuator line was intended as a lifting line technique for CFD applications. In this paper we prove – theoretically and practically – that smearing the forces of the actuator line in the flow domain leads to smeared velocity fields. By combining a near-wake representation of the trailed vorticity with a viscous vortex core model, the missing induction from the smeared velocity is recovered and a lifting line for CFD simulations established.
Maarten Paul van der Laan, Søren Juhl Andersen, Néstor Ramos García, Nikolas Angelou, Georg Raimund Pirrung, Søren Ott, Mikael Sjöholm, Kim Hylling Sørensen, Julio Xavier Vianna Neto, Mark Kelly, Torben Krogh Mikkelsen, and Gunner Christian Larsen
Wind Energ. Sci., 4, 251–271, https://doi.org/10.5194/wes-4-251-2019, https://doi.org/10.5194/wes-4-251-2019, 2019
Short summary
Short summary
Over the past few decades, single-rotor wind turbines have increased in size with the blades being extended toward lengths of 100 m. An alternative upscaling of turbines can be achieved by using multi-rotor wind turbines. In this article, measurements and numerical simulations of a utility-scale four-rotor wind turbine show that rotor interaction leads to increased energy production and faster wake recovery; these findings may allow for the design of wind farms with improved energy production.
Mads H. Aa. Madsen, Frederik Zahle, Niels N. Sørensen, and Joaquim R. R. A. Martins
Wind Energ. Sci., 4, 163–192, https://doi.org/10.5194/wes-4-163-2019, https://doi.org/10.5194/wes-4-163-2019, 2019
Short summary
Short summary
The wind energy industry relies heavily on CFD to analyze new designs. This paper investigates a way to utilize CFD further upstream the design process where lower-fidelity methods are used. We present the first comprehensive 3-D CFD adjoint-based shape optimization of a 10 MW modern offshore wind turbine. The present work shows that, with the right tools, we can model the entire geometry, including the root, and optimize modern wind turbine rotors at the cost of a few hundred CFD evaluations.
Georg Raimund Pirrung and Maarten Paul van der Laan
Wind Energ. Sci. Discuss., https://doi.org/10.5194/wes-2018-59, https://doi.org/10.5194/wes-2018-59, 2018
Revised manuscript not accepted
Short summary
Short summary
Wind turbine loading decreases towards the blade tip due to the velocities induced by the tip vortex and the spanwise flow. It has been shown that the tip loss factor applied on the aerodynamic forces should be different for the axial and tangential loading of the turbine due to the rotation of the resulting force vector caused by the induced velocity. The present article contains the derivation of a simple correction for the tangential load factor that takes this rotation into account.
Georg Raimund Pirrung and Helge Aagaard Madsen
Wind Energ. Sci., 3, 545–551, https://doi.org/10.5194/wes-3-545-2018, https://doi.org/10.5194/wes-3-545-2018, 2018
Short summary
Short summary
A wind turbine sees an overshoot in loading after a step change in pitch angle because the wake takes some time to reach a new equilibrium. The time constants of this dynamic inflow effect are expected to decrease significantly towards the blade tip. This radial dependency has not been found to the expected extent in previous analyses of force measurements from the NASA Ames Phase VI experiment. In the present article the findings from the experiment are explained based on a simple vortex model.
Georg R. Pirrung, Helge A. Madsen, and Scott Schreck
Wind Energ. Sci., 2, 521–532, https://doi.org/10.5194/wes-2-521-2017, https://doi.org/10.5194/wes-2-521-2017, 2017
Short summary
Short summary
Current fast aeroelastic wind turbine codes suitable for certification lack an induction model for standstill conditions. A near-wake model for wind turbines in operation is extended to cover these conditions. The model is validated in aerodynamic simulations of the NREL/NASA Ames Phase VI rotor. Good agreement with the experiments has been obtained in attached flow and beginning separation. Aeroelastic simulations of the DTU 10 MW turbine in standstill indicate a minor impact of the model.
Maarten Paul van der Laan and Niels Nørmark Sørensen
Wind Energ. Sci., 2, 285–294, https://doi.org/10.5194/wes-2-285-2017, https://doi.org/10.5194/wes-2-285-2017, 2017
Short summary
Short summary
In recent years, wind farms have grown in size and are more frequently placed in wind farm clusters. This means that large-scale effects such as the interaction of the Coriolis force and wind farm wakes are becoming more important for designing energy efficient wind farms. The literature disagrees on the turning direction of a wind farm wake due to the Coriolis force. In this article, we explain why the Coriolis force turns a wind farm wake clockwise in the Northern Hemisphere.
Georg Pirrung, Vasilis Riziotis, Helge Madsen, Morten Hansen, and Taeseong Kim
Wind Energ. Sci., 2, 15–33, https://doi.org/10.5194/wes-2-15-2017, https://doi.org/10.5194/wes-2-15-2017, 2017
Short summary
Short summary
The certification process of a wind turbine requires simulations of a coupled structural and aerodynamic wind turbine model in many different external conditions. Due to the large number of load cases, the complexity of the aerodynamics models has to be limited. In this paper, a simplified vortex method based aerodynamics model is described. It is shown that this model, which is fast enough for use in a certification context, can produce results similar to those of a more complex vortex model.
Dalibor Cavar, Pierre-Elouan Réthoré, Andreas Bechmann, Niels N. Sørensen, Benjamin Martinez, Frederik Zahle, Jacob Berg, and Mark C. Kelly
Wind Energ. Sci., 1, 55–70, https://doi.org/10.5194/wes-1-55-2016, https://doi.org/10.5194/wes-1-55-2016, 2016
Short summary
Short summary
Feasibility of a freely available CFD tool, OpenFOAM, in calculating flows of general relevance to the wind industry is investigated by comparing several aspects of its performance to a well-established in-house EllipSys3D solver. The comparison is focused on CFD solver demands regarding grid generation process and computational time.
The quality and accuracy of the achieved results are investigated by conducting the computations using identical/similar solver parameters and numerical setups..
Related subject area
Thematic area: Fluid mechanics | Topic: Wind turbine aerodynamics
Investigation of blade flexibility effects on the loads and wake of a 15 MW wind turbine using a flexible actuator line method
On optimizing the sensor spacing for pressure measurements on wind turbine airfoils
Experimental analysis of a horizontal-axis wind turbine with swept blades using PIV data
Aerodynamic characterisation of a thrust-scaled IEA 15 MW wind turbine model: experimental insights using PIV data
Going beyond BEM with BEM: an insight into dynamic inflow effects on floating wind turbines
Quantifying the impact of modeling fidelity on different substructure concepts – Part 2: Code-to-code comparison in realistic environmental conditions
Wind turbine rotors in surge motion: new insights into unsteady aerodynamics of floating offshore wind turbines (FOWTs) from experiments and simulations
An insight into the capability of the actuator line method to resolve tip vortices
Aerodynamic model comparison for an X-shaped vertical-axis wind turbine
Development and application of a mesh generator intended for unsteady vortex-lattice method simulations of wind turbines and wind farms
An experimental study on the aerodynamic loads of a floating offshore wind turbine under imposed motions
Force Partitioning Analysis of Vortex-Induced Vibrations of Wind Turbine Tower Sections
Developing a digital twin framework for wind tunnel testing: validation of turbulent inflow and airfoil load applications
Influence of rotor blade flexibility on the near-wake behavior of the NREL 5 MW wind turbine
Field-data-based validation of an aero-servo-elastic solver for high-fidelity large-eddy simulations of industrial wind turbines
An analytical linear two-dimensional actuator disc model and comparisons with computational fluid dynamics (CFD) simulations
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 project Phase III
Forced-motion simulations of vortex-induced vibrations of wind turbine blades – a study of sensitivities
Towards smart blades for vertical axis wind turbines: different airfoil shapes and tip speed ratios
Numerical study of the unsteady blade root aerodynamics of a 2 MW wind turbine equipped with vortex generators
Generalized analytical body force model for actuator disc computations of wind turbines
Nonlinear inviscid aerodynamics of a wind turbine rotor in surge, sway, and yaw motions using a free-wake panel method
OC6 project Phase III: validation of the aerodynamic loading on a wind turbine rotor undergoing large motion caused by a floating support structure
A simple vortex model applied to an idealized rotor in sheared inflow
Comparison of free vortex wake and blade element momentum results against large-eddy simulation results for highly flexible turbines under challenging inflow conditions
Numerical simulations of ice accretion on wind turbine blades: are performance losses due to ice shape or surface roughness?
Progress in the validation of rotor aerodynamic codes using field data
A comparison of dynamic inflow models for the blade element momentum method
Model tests of a 10 MW semi-submersible floating wind turbine under waves and wind using hybrid method to integrate the rotor thrust and moments
Atmospheric rotating rig testing of a swept blade tip and comparison with multi-fidelity aeroelastic simulations
A WaveNet-based fully stochastic dynamic stall model
Experimental analysis of the dynamic inflow effect due to coherent gusts
High-Reynolds-number wind turbine blade equipped with root spoilers – Part 2: Impact on energy production and turbine lifetime
Wind tunnel investigation of the aerodynamic response of two 15 MW floating wind turbines
Vertical wake deflection for floating wind turbines by differential ballast control
High-fidelity aeroelastic analyses of wind turbines in complex terrain: fluid–structure interaction and aerodynamic modeling
Development of a wireless, non-intrusive, MEMS-based pressure and acoustic measurement system for large-scale operating wind turbine blades
How should the lift and drag forces be calculated from 2-D airfoil data for dihedral or coned wind turbine blades?
Francois Trigaux, Philippe Chatelain, and Grégoire Winckelmans
Wind Energ. Sci., 9, 1765–1789, https://doi.org/10.5194/wes-9-1765-2024, https://doi.org/10.5194/wes-9-1765-2024, 2024
Short summary
Short summary
In this research, the impact of blade flexibility is investigated for a very large wind turbine using numerical simulations. It is shown that bending and torsion decrease the power production and affect aerodynamic loads. Blade deformation also affects the flow of wind behind the turbine, resulting in a higher mean velocity. Our study highlights the importance of including blade flexibility in the simulation of large wind turbines to obtain accurate power and load predictions.
Erik K. Fritz, Christopher L. Kelley, and Kenneth A. Brown
Wind Energ. Sci., 9, 1713–1726, https://doi.org/10.5194/wes-9-1713-2024, https://doi.org/10.5194/wes-9-1713-2024, 2024
Short summary
Short summary
This study investigates the benefits of optimizing the spacing of pressure sensors for measurement campaigns on wind turbine blades and airfoils. It is demonstrated that local aerodynamic properties can be estimated considerably more accurately when the sensor layout is optimized compared to commonly used simpler sensor layouts. This has the potential to reduce the number of sensors without losing measurement accuracy and, thus, reduce the instrumentation complexity and experiment cost.
Erik Fritz, Koen Boorsma, and Carlos Ferreira
Wind Energ. Sci., 9, 1617–1629, https://doi.org/10.5194/wes-9-1617-2024, https://doi.org/10.5194/wes-9-1617-2024, 2024
Short summary
Short summary
This study presents results from a wind tunnel experiment on a model wind turbine with swept blades, thus blades curved in the rotor plane. Using a non-intrusive measurement technique, the flow around the turbine blades was measured from which blade-level aerodynamics are derived in post-processing. The detailed experimental database gives insight into swept-blade aerodynamics and has great value in validating numerical tools, which aim at simulating swept wind turbine blades.
Erik Fritz, André Ribeiro, Koen Boorsma, and Carlos Ferreira
Wind Energ. Sci., 9, 1173–1187, https://doi.org/10.5194/wes-9-1173-2024, https://doi.org/10.5194/wes-9-1173-2024, 2024
Short summary
Short summary
This study presents results from a wind tunnel experiment on a model wind turbine. Using a non-intrusive measurement technique, the flow around the turbine blades was measured. In post-processing, the blade-level aerodynamics are derived from the measured flow fields. The detailed experimental database has great value in validating numerical tools of varying complexity, which aim at simulating wind turbine aerodynamics as accurately as possible.
Francesco Papi, Jason Jonkman, Amy Robertson, and Alessandro Bianchini
Wind Energ. Sci., 9, 1069–1088, https://doi.org/10.5194/wes-9-1069-2024, https://doi.org/10.5194/wes-9-1069-2024, 2024
Short summary
Short summary
Blade element momentum (BEM) theory is the backbone of many industry-standard aerodynamic models. However, the analysis of floating offshore wind turbines (FOWTs) introduces new challenges, which could put BEM models to the test. This study systematically compares four aerodynamic models, ranging from BEM to computational fluid dynamics, in an attempt to shed light on the unsteady aerodynamic phenomena that are at stake in FOWTs and whether BEM is able to model them appropriately.
Francesco Papi, Giancarlo Troise, Robert Behrens de Luna, Joseph Saverin, Sebastian Perez-Becker, David Marten, Marie-Laure Ducasse, and Alessandro Bianchini
Wind Energ. Sci., 9, 981–1004, https://doi.org/10.5194/wes-9-981-2024, https://doi.org/10.5194/wes-9-981-2024, 2024
Short summary
Short summary
Wind turbines need to be simulated for thousands of hours to estimate design loads. Mid-fidelity numerical models are typically used for this task to strike a balance between computational cost and accuracy. The considerable displacements of floating wind turbines may be a challenge for some of these models. This paper enhances comprehension of how modeling theories affect floating wind turbine loads by comparing three codes across three turbines, simulated in a real environment.
Christian W. Schulz, Stefan Netzband, Umut Özinan, Po Wen Cheng, and Moustafa Abdel-Maksoud
Wind Energ. Sci., 9, 665–695, https://doi.org/10.5194/wes-9-665-2024, https://doi.org/10.5194/wes-9-665-2024, 2024
Short summary
Short summary
Understanding the underlying physical phenomena of the aerodynamics of floating offshore wind turbines (FOWTs) is crucial for successful simulations. No consensus has been reached in the research community on which unsteady aerodynamic phenomena are relevant and how much they can influence the loads acting on a FOWT. This work contributes to the understanding and characterisation of such unsteady phenomena using a novel experimental approach and comprehensive numerical investigations.
Pier Francesco Melani, Omar Sherif Mohamed, Stefano Cioni, Francesco Balduzzi, and Alessandro Bianchini
Wind Energ. Sci., 9, 601–622, https://doi.org/10.5194/wes-9-601-2024, https://doi.org/10.5194/wes-9-601-2024, 2024
Short summary
Short summary
The actuator line method (ALM) is a powerful tool for wind turbine simulation but struggles to resolve tip effects. The reason is still unclear. To investigate this, we use advanced angle of attack sampling and vortex tracking techniques to analyze the flow around a NACA0018 finite wing, simulated with ALM and blade-resolved computational fluid dynamics. Results show that the ALM can account for tip effects if the correct angle of attack sampling and force projection strategies are adopted.
Adhyanth Giri Ajay, Laurence Morgan, Yan Wu, David Bretos, Aurelio Cascales, Oscar Pires, and Carlos Ferreira
Wind Energ. Sci., 9, 453–470, https://doi.org/10.5194/wes-9-453-2024, https://doi.org/10.5194/wes-9-453-2024, 2024
Short summary
Short summary
This paper compares six different numerical models to predict the performance of an X-shaped vertical-axis wind turbine, offering insights into how it works in 3D when its blades are fixed at specific angles. The results showed the 3D models here reliably predict the performance while still taking this turbine's complex aerodynamics into account compared to 2D models. Further, these blade angles caused more complexity in predicting the turbine's behaviour, which is highlighted in this paper.
Bruno A. Roccia, Luis R. Ceballos, Marcos L. Verstraete, and Cristian G. Gebhardt
Wind Energ. Sci., 9, 385–416, https://doi.org/10.5194/wes-9-385-2024, https://doi.org/10.5194/wes-9-385-2024, 2024
Short summary
Short summary
In the literature there is a lack of meshing tools when it comes to building aerodynamic grids of wind turbines/farms to be used along with potential flow solvers. In this work, we present a detailed description of the geometric modeling and computational implementation of an interactive mesh generator, named UVLMeshGen, for onshore/offshore wind farms. The work is completed by providing a series of aerodynamic results related to wind turbines/farms to show the capacity of the mesh generator.
Federico Taruffi, Felipe Novais, and Axelle Viré
Wind Energ. Sci., 9, 343–358, https://doi.org/10.5194/wes-9-343-2024, https://doi.org/10.5194/wes-9-343-2024, 2024
Short summary
Short summary
Floating wind turbines are subject to complex aerodynamics that are not yet fully understood. Lab-scale experiments are crucial for capturing these phenomena and validate numerical tools. This paper presents a new wind tunnel experimental setup able to study the response of a wind turbine rotor when subjected to prescribed motions in 6 degrees of freedom. The observed unsteady effects underscore the importance of pursuing research on the impact of floater motions on wind turbine performance.
Shyam VimalKumar, Delphine De Tavernier, Dominic von Terzi, Marco Belloli, and Axelle Viré
Wind Energ. Sci. Discuss., https://doi.org/10.5194/wes-2024-10, https://doi.org/10.5194/wes-2024-10, 2024
Revised manuscript accepted for WES
Short summary
Short summary
When standing still without a nacelle or blades, the vibrations on the wind turbine tower are a concern to its structural health. This study finds that the air which flows around the tower recirculates behind the tower, forming so-called wakes. This wakes initiates the vibration, and the movement itself keeps the vibration increasing or decreasing depending on the wind speed. The current study uses a methodology called Force-partitioning to analyse this in depth.
Rishabh Mishra, Emmanuel Guilmineau, Ingrid Neunaber, and Caroline Braud
Wind Energ. Sci., 9, 235–252, https://doi.org/10.5194/wes-9-235-2024, https://doi.org/10.5194/wes-9-235-2024, 2024
Short summary
Short summary
To investigate the impact of turbulence on aerodynamic forces, we first model turbulent kinetic energy decay theoretically using the Taylor length scale and employ this model to create a digital wind tunnel replica for simulating grid-generated turbulence. Experimental validation shows good alignment among theory, simulations, and experiments, paving the way for aerodynamic simulations. Finally, we successfully use the digital replica to obtain force coefficients for a 2D rotor blade section.
Leo Höning, Laura J. Lukassen, Bernhard Stoevesandt, and Iván Herráez
Wind Energ. Sci., 9, 203–218, https://doi.org/10.5194/wes-9-203-2024, https://doi.org/10.5194/wes-9-203-2024, 2024
Short summary
Short summary
This study analyzes the impact of wind turbine rotor blade flexibility on the aerodynamic loading of the blades and the consequential wind characteristics in the near wake of the turbine. It is shown that gravitation leads to rotational periodic fluctuations of blade loading, which directly impacts the trajectory of the blade tip vortex at different rotor blade positions while also resulting in a non-uniform wind velocity deficit in the wake of the wind turbine.
Etienne Muller, Simone Gremmo, Félix Houtin-Mongrolle, Bastien Duboc, and Pierre Bénard
Wind Energ. Sci., 9, 25–48, https://doi.org/10.5194/wes-9-25-2024, https://doi.org/10.5194/wes-9-25-2024, 2024
Short summary
Short summary
This article presents an advanced tool designed for the high-fidelity and high-performance simulation of operating wind turbines, allowing for instance the computation of a blade deformation, as well as of the surrounding airflow. As this tool relies on coupling two existing codes, the coupling strategy is first described in depth. The article then compares the code results to field data for validation.
Helge Aagaard Madsen
Wind Energ. Sci., 8, 1853–1872, https://doi.org/10.5194/wes-8-1853-2023, https://doi.org/10.5194/wes-8-1853-2023, 2023
Short summary
Short summary
We present a linear analytical solution for a two-dimensional (2-D) actuator disc (AD) for a plane disc, a yawed disc and a coned disc. Comparisons of the 2-D model with three-dimensional computational fluid dynamics (CFD) AD simulations for a circular yawed disc and with an axis-symmetric CFD simulation of a coned disc show good correlation for the normal velocity component of the disc. This indicates that the 2-D AD model could form the basis for a consistent, simple new rotor induction model.
Stefano Cioni, Francesco Papi, Leonardo Pagamonci, Alessandro Bianchini, Néstor Ramos-García, Georg Pirrung, Rémi Corniglion, Anaïs Lovera, Josean Galván, Ronan Boisard, Alessandro Fontanella, Paolo Schito, Alberto Zasso, Marco Belloli, Andrea Sanvito, Giacomo Persico, Lijun Zhang, Ye Li, Yarong Zhou, Simone Mancini, Koen Boorsma, Ricardo Amaral, Axelle Viré, Christian W. Schulz, Stefan Netzband, Rodrigo Soto-Valle, David Marten, Raquel Martín-San-Román, Pau Trubat, Climent Molins, Roger Bergua, Emmanuel Branlard, Jason Jonkman, and Amy Robertson
Wind Energ. Sci., 8, 1659–1691, https://doi.org/10.5194/wes-8-1659-2023, https://doi.org/10.5194/wes-8-1659-2023, 2023
Short summary
Short summary
Simulations of different fidelities made by the participants of the OC6 project Phase III are compared to wind tunnel wake measurements on a floating wind turbine. Results in the near wake confirm that simulations and experiments tend to diverge from the expected linearized quasi-steady behavior when the reduced frequency exceeds 0.5. In the far wake, the impact of platform motion is overestimated by simulations and even seems to be oriented to the generation of a wake less prone to dissipation.
Christian Grinderslev, Felix Houtin-Mongrolle, Niels Nørmark Sørensen, Georg Raimund Pirrung, Pim Jacobs, Aqeel Ahmed, and Bastien Duboc
Wind Energ. Sci., 8, 1625–1638, https://doi.org/10.5194/wes-8-1625-2023, https://doi.org/10.5194/wes-8-1625-2023, 2023
Short summary
Short summary
In standstill conditions wind turbines are at risk of vortex-induced vibrations (VIVs). VIVs can become large and lead to significant fatigue of the wind turbine structure over time. Thus it is important to have tools that can accurately compute this complex phenomenon. This paper studies the sensitivities to the chosen models of computational fluid dynamics (CFD) simulations when modelling VIVs and finds that much care is needed when setting up simulations, especially for specific flow angles.
Mohammad Rasoul Tirandaz, Abdolrahim Rezaeiha, and Daniel Micallef
Wind Energ. Sci., 8, 1403–1424, https://doi.org/10.5194/wes-8-1403-2023, https://doi.org/10.5194/wes-8-1403-2023, 2023
Short summary
Short summary
Vertical axis wind turbines experience a variation of torque and power throughout their rotation. Traditional non-morphing blades are intrinsically not able to respond to this variation, resulting in a turbine which has suboptimal performance. In principle, it is possible to have a morphing blade that adapts to the blade's rotation and changes its geometry in such a way as to optimise the performance of the turbine. This paper addresses the question of how such blade should morph as it rotates.
Ferdinand Seel, Thorsten Lutz, and Ewald Krämer
Wind Energ. Sci., 8, 1369–1385, https://doi.org/10.5194/wes-8-1369-2023, https://doi.org/10.5194/wes-8-1369-2023, 2023
Short summary
Short summary
Vortex generators are evaluated on a 2 MW wind turbine rotor blade by computational fluid dynamic methods. Those devices delay flow separation on the airfoils and thus increase their efficiency. On the wind turbine blade, rotational phenomena (e.g. rotational augmentation) appear and interact with the vortices from the vortex generators. The understanding of those interactions is crucial in order to optimise the placement of the vortex generators and evaluate their real efficiency on the blade.
Jens N. Sørensen
Wind Energ. Sci., 8, 1017–1027, https://doi.org/10.5194/wes-8-1017-2023, https://doi.org/10.5194/wes-8-1017-2023, 2023
Short summary
Short summary
The paper presents a simple analytical model that, with surprisingly good accuracy, represents the loading for virtually any horizontal axis wind turbine, independent of size and operating regime. The aim of the model is to have a simple tool that may represent the loading of any wind turbine without having access to the details regarding the specific geometry and airfoil data, information that is normally kept confidential by the manufacturer of the turbine.
André F. P. Ribeiro, Damiano Casalino, and Carlos S. Ferreira
Wind Energ. Sci., 8, 661–675, https://doi.org/10.5194/wes-8-661-2023, https://doi.org/10.5194/wes-8-661-2023, 2023
Short summary
Short summary
Floating offshore wind turbines move due to not having a rigid foundation. Hence, as the blades rotate they experience more complex aerodynamics than standard onshore wind turbines. In this paper, we show computational simulations of a wind turbine rotor moving in various ways and quantify the effects of the motion in the forces acting on the blades. We show that these forces behave in nonlinear ways in some cases.
Roger Bergua, Amy Robertson, Jason Jonkman, Emmanuel Branlard, Alessandro Fontanella, Marco Belloli, Paolo Schito, Alberto Zasso, Giacomo Persico, Andrea Sanvito, Ervin Amet, Cédric Brun, Guillén Campaña-Alonso, Raquel Martín-San-Román, Ruolin Cai, Jifeng Cai, Quan Qian, Wen Maoshi, Alec Beardsell, Georg Pirrung, Néstor Ramos-García, Wei Shi, Jie Fu, Rémi Corniglion, Anaïs Lovera, Josean Galván, Tor Anders Nygaard, Carlos Renan dos Santos, Philippe Gilbert, Pierre-Antoine Joulin, Frédéric Blondel, Eelco Frickel, Peng Chen, Zhiqiang Hu, Ronan Boisard, Kutay Yilmazlar, Alessandro Croce, Violette Harnois, Lijun Zhang, Ye Li, Ander Aristondo, Iñigo Mendikoa Alonso, Simone Mancini, Koen Boorsma, Feike Savenije, David Marten, Rodrigo Soto-Valle, Christian W. Schulz, Stefan Netzband, Alessandro Bianchini, Francesco Papi, Stefano Cioni, Pau Trubat, Daniel Alarcon, Climent Molins, Marion Cormier, Konstantin Brüker, Thorsten Lutz, Qing Xiao, Zhongsheng Deng, Florence Haudin, and Akhilesh Goveas
Wind Energ. Sci., 8, 465–485, https://doi.org/10.5194/wes-8-465-2023, https://doi.org/10.5194/wes-8-465-2023, 2023
Short summary
Short summary
This 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.
Mac Gaunaa, Niels Troldborg, and Emmanuel Branlard
Wind Energ. Sci., 8, 503–513, https://doi.org/10.5194/wes-8-503-2023, https://doi.org/10.5194/wes-8-503-2023, 2023
Short summary
Short summary
We present an analytical vortex model. Despite its simplicity, the model is fully consistent with 1D momentum theory. It shows that the flow through a non-uniformly loaded rotor operating in non-uniform inflow behaves locally as predicted by 1D momentum theory. As a consequence, the local power coefficient (based on local inflow) of an ideal rotor is unaltered by the presence of shear. Finally, the model shows that there is no cross-shear deflection of the wake of a rotor in sheared inflow.
Kelsey Shaler, Benjamin Anderson, Luis A. Martínez-Tossas, Emmanuel Branlard, and Nick Johnson
Wind Energ. Sci., 8, 383–399, https://doi.org/10.5194/wes-8-383-2023, https://doi.org/10.5194/wes-8-383-2023, 2023
Short summary
Short summary
Free-vortex wake (OLAF) and low-fidelity blade-element momentum (BEM) structural results are compared to high-fidelity simulation results for a flexible downwind turbine for varying inflow conditions. Overall, OLAF results were more consistent than BEM results when compared to SOWFA results under challenging inflow conditions. Differences between OLAF and BEM results were dominated by yaw misalignment angle, with varying shear exponent and turbulence intensity causing more subtle differences.
Francesco Caccia and Alberto Guardone
Wind Energ. Sci., 8, 341–362, https://doi.org/10.5194/wes-8-341-2023, https://doi.org/10.5194/wes-8-341-2023, 2023
Short summary
Short summary
Ice roughness deteriorates wind turbine aerodynamics. We have shown numerically that this also occurs when complex ice shapes are present on the leading edge, as long as the blade's wet region extends beyond the ice shape itself and roughness elements are high enough. Such features are typical of icing events on wind turbines but are not captured by current icing simulation tools. Future research should focus on correctly computing both the wet region of the blade and the roughness height.
Koen Boorsma, Gerard Schepers, Helge Aagard Madsen, Georg Pirrung, Niels Sørensen, Galih Bangga, Manfred Imiela, Christian Grinderslev, Alexander Meyer Forsting, Wen Zhong Shen, Alessandro Croce, Stefano Cacciola, Alois Peter Schaffarczyk, Brandon Lobo, Frederic Blondel, Philippe Gilbert, Ronan Boisard, Leo Höning, Luca Greco, Claudio Testa, Emmanuel Branlard, Jason Jonkman, and Ganesh Vijayakumar
Wind Energ. Sci., 8, 211–230, https://doi.org/10.5194/wes-8-211-2023, https://doi.org/10.5194/wes-8-211-2023, 2023
Short summary
Short summary
Within the framework of the fourth phase of the International Energy Agency's (IEA) Wind Task 29, a large comparison exercise between measurements and aeroelastic simulations has been carried out. Results were obtained from more than 19 simulation tools of various fidelity, originating from 12 institutes and compared to state-of-the-art field measurements. The result is a unique insight into the current status and accuracy of rotor aerodynamic modeling.
Simone Mancini, Koen Boorsma, Gerard Schepers, and Feike Savenije
Wind Energ. Sci., 8, 193–210, https://doi.org/10.5194/wes-8-193-2023, https://doi.org/10.5194/wes-8-193-2023, 2023
Short summary
Short summary
Modern wind turbines are subject to complex wind conditions that are far from the hypothesis of steady uniform inflow at the core of blade element momentum methods (the current industry standard for wind turbine design). Various corrections have been proposed to model this complexity. The present work focuses on modelling the unsteady evolution of wind turbine wakes (dynamic inflow), comparing the different corrections available and highlighting their effects on design load predictions.
Felipe Vittori, José Azcona, Irene Eguinoa, Oscar Pires, Alberto Rodríguez, Álex Morató, Carlos Garrido, and Cian Desmond
Wind Energ. Sci., 7, 2149–2161, https://doi.org/10.5194/wes-7-2149-2022, https://doi.org/10.5194/wes-7-2149-2022, 2022
Short summary
Short summary
This paper describes the results of a wave tank test campaign of a scaled SATH 10 MW INNWIND floating platform. The software-in-the-loop (SiL) hybrid method was used to include the wind turbine thrust and the in-plane rotor moments. Experimental results are compared with a numerical model developed in OpenFAST of the floating wind turbine. The results are discussed, identifying limitations of the numerical models and obtaining conclusions on how to improve them.
Thanasis Barlas, Georg Raimund Pirrung, Néstor Ramos-García, Sergio González Horcas, Ang Li, and Helge Aagaard Madsen
Wind Energ. Sci., 7, 1957–1973, https://doi.org/10.5194/wes-7-1957-2022, https://doi.org/10.5194/wes-7-1957-2022, 2022
Short summary
Short summary
An aeroelastically optimized curved wind turbine blade tip is designed, manufactured, and tested on a novel outdoor rotating rig facility at the Risø campus of the Technical University of Denmark. Detailed aerodynamic measurements for various atmospheric conditions and results are compared to a series of in-house aeroelastic tools with a range of fidelities in aerodynamic modeling. The comparison highlights details in the ability of the codes to predict the performance of such a curved tip.
Jan-Philipp Küppers and Tamara Reinicke
Wind Energ. Sci., 7, 1889–1903, https://doi.org/10.5194/wes-7-1889-2022, https://doi.org/10.5194/wes-7-1889-2022, 2022
Short summary
Short summary
Airfoils play a major role in the technical harnessing of energy from currents such as wind and water. When the angle of attack of a wing changes dynamically, the forces on the wing often change more than would have been assumed from static measurements alone. Since these dynamic forces have a strong influence, e.g., on the performance of airplanes and wind turbines, a neural-network-based model was created that can predict these loads and their stochastic fluctuations.
Frederik Berger, Lars Neuhaus, David Onnen, Michael Hölling, Gerard Schepers, and Martin Kühn
Wind Energ. Sci., 7, 1827–1846, https://doi.org/10.5194/wes-7-1827-2022, https://doi.org/10.5194/wes-7-1827-2022, 2022
Short summary
Short summary
We proof the dynamic inflow effect due to gusts in wind tunnel experiments with MoWiTO 1.8 in the large wind tunnel of ForWind – University of Oldenburg, where we created coherent gusts with an active grid. The effect is isolated in loads and rotor flow by comparison of a quasi-steady and a dynamic case. The observed effect is not caught by common dynamic inflow engineering models. An improvement to the Øye dynamic inflow model is proposed, matching experiment and corresponding FVWM simulations.
Thomas Potentier, Emmanuel Guilmineau, Arthur Finez, Colin Le Bourdat, and Caroline Braud
Wind Energ. Sci., 7, 1771–1790, https://doi.org/10.5194/wes-7-1771-2022, https://doi.org/10.5194/wes-7-1771-2022, 2022
Short summary
Short summary
A wind turbine blade equipped with root spoilers is analysed using time domain aeroelastic simulations to assess the impact of passive devices on the turbine AEP and lifetime. A novel way to account for aerofoil-generated unsteadiness in the fatigue calculation is proposed and detailed. The outcome shows that spoilers, on average, can increase the AEP of the turbine. However, the structural impacts on the turbine can be severe if not accounted for initially in the turbine design.
Alessandro Fontanella, Alan Facchinetti, Simone Di Carlo, and Marco Belloli
Wind Energ. Sci., 7, 1711–1729, https://doi.org/10.5194/wes-7-1711-2022, https://doi.org/10.5194/wes-7-1711-2022, 2022
Short summary
Short summary
The aerodynamics of floating wind turbines is complicated by large motions permitted by the foundation. The interaction between turbine, wind, and wake is not yet fully understood. The wind tunnel experiments of this paper shed light on the aerodynamic force and wake response of the floating IEA 15 MW turbine subjected to platform motion as would occur during normal operation. This will help future research on turbine and wind farm control.
Emmanouil M. Nanos, Carlo L. Bottasso, Simone Tamaro, Dimitris I. Manolas, and Vasilis A. Riziotis
Wind Energ. Sci., 7, 1641–1660, https://doi.org/10.5194/wes-7-1641-2022, https://doi.org/10.5194/wes-7-1641-2022, 2022
Short summary
Short summary
A novel way of wind farm control is presented where the wake is deflected vertically to reduce interactions with downstream turbines. This is achieved by moving ballast in a floating offshore platform in order to pitch the support structure and thereby tilt the wind turbine rotor disk. The study considers the effects of this new form of wake control on the aerodynamics of the steering and wake-affected turbines, on the structure, and on the ballast motion system.
Giorgia Guma, Philipp Bucher, Patrick Letzgus, Thorsten Lutz, and Roland Wüchner
Wind Energ. Sci., 7, 1421–1439, https://doi.org/10.5194/wes-7-1421-2022, https://doi.org/10.5194/wes-7-1421-2022, 2022
Short summary
Short summary
Wind turbine aeroelasticity is becoming more and more important because turbine sizes are increasingly leading to more slender blades. On the other hand, complex terrains are of interest because they are far away from urban areas. These regions are characterized by low velocities and high turbulence and are mostly influenced by the presence of forest, and that is why it is necessary to develop high-fidelity tools to correctly simulate the wind turbine's response.
Sarah Barber, Julien Deparday, Yuriy Marykovskiy, Eleni Chatzi, Imad Abdallah, Gregory Duthé, Michele Magno, Tommaso Polonelli, Raphael Fischer, and Hanna Müller
Wind Energ. Sci., 7, 1383–1398, https://doi.org/10.5194/wes-7-1383-2022, https://doi.org/10.5194/wes-7-1383-2022, 2022
Short summary
Short summary
Aerodynamic and acoustic field measurements on operating large-scale wind turbines are key for the further reduction in the costs of wind energy. In this work, a novel cost-effective MEMS (micro-electromechanical systems)-based aerodynamic and acoustic wireless measurement system that is thin, non-intrusive, easy to install, low power and self-sustaining is designed and tested.
Ang Li, Mac Gaunaa, Georg Raimund Pirrung, Alexander Meyer Forsting, and Sergio González Horcas
Wind Energ. Sci., 7, 1341–1365, https://doi.org/10.5194/wes-7-1341-2022, https://doi.org/10.5194/wes-7-1341-2022, 2022
Short summary
Short summary
A consistent method of using two-dimensional airfoil data when using generalized lifting-line methods for the aerodynamic load calculation of non-planar horizontal-axis wind turbines is described. The important conclusions from the unsteady two-dimensional airfoil aerodynamics are highlighted. The impact of using a simplified approach instead of using the full model on the prediction of the aerodynamic performance of non-planar rotors is shown numerically for different aerodynamic models.
Cited articles
Bak, C., Zahle, F., Bitsche, R., Kim, T., Yde, A., Henriksen, L., Hansen, M.,
Blasques, J., Gaunaa, M., and Natarajan, A.: Description of the DTU 10 MW Reference Wind Turbine, technical report, DTU Wind Energy Report_I_0092, DTU Wind Energy, 2013. a
Barlas, T., Pirrung, G. R., Ramos-García, N., Horcas, S. G., Mikkelsen, R. F., Olsen, A. S., and Gaunaa, M.: Wind tunnel testing of a swept tip shape and comparison with multi-fidelity aerodynamic simulations, Wind Energ. Sci., 6, 1311–1324, https://doi.org/10.5194/wes-6-1311-2021, 2021. a
Bearman, P. W.: Circular cylinder wakes and vortex-induced vibrations,
J. Fluid. Struct., 27, 648–658,
https://doi.org/10.1016/j.jfluidstructs.2011.03.021, 2011. a
Bechmann, A., Sørensen, N., and Zahle, F.: CFD simulations of the MEXICO
rotor, Wind Energy, 14, 677–689, 2011. a
Bertagnolio, F., Gaunaa, M., Hansen, M., Sørensen, N., and Rasmussen, F.:
Computation of aerodynamic damping for wind turbine applications, in: CD-Rom
proceedings, edited by: Tsahalis, D., Greek Association of Computational
Mechanics, 4th GRACM Congress on Computational Mechanics, Patras, Greece,
27–29 June 2002,
https://backend.orbit.dtu.dk/ws/portalfiles/portal/148414970/paper.pdf
(last access: 1 November 2022), 2002. a
Blevins, R.: Flow-induced vibration, Krieger Publishing Company, Malabar,
Florida, USA, 2nd edn., ISBN 1-57524-183-8, 2001. a
Blevins, R. D. and Coughran, C. S.: Experimental investigation of
vortex-induced vibration in one and two dimensions with variable mass,
damping, and reynolds number, J. Fluid Eng., 131, 1012021–1012027, https://doi.org/10.1115/1.3222904, 2009. a
Bortolotti, P., Canet Tarrés, H., Dykes, K., Merz, K., Sethuraman, L.,
Verelst, D., and Zahle, F.: Systems Engineering in Wind Energy – WP2.1
Reference Wind Turbines, Tech. rep., National Renewable Energy Laboratory
(NREL),
https://www.osti.gov/biblio/1529216-iea-wind-tcp-task-systems-engineering-wind-energy-wp2-reference-wind-turbines (last access: 1 November 2022),
2019. a, b, c, d
Ceyhan, J. S. O., Boorsma, K., Gonzalez, A., Munduate, X., Pires, O.,
Sørensen, N., Ferreira, C., Sieros, G., Madsen, J., Voutsinas, S., Lutz,
T., Barakos, G., Colonia, S., Heißelmann, H., Meng, F., and Croce, A.:
Latest results from the EU project AVATAR: Aerodynamic modelling of 10
MW wind turbines, J. Phys.-Conf. Ser., 753, 022017,
https://doi.org/10.1088/1742-6596/753/2/022017, 2016. a
DTU Computing Center: DTU Computing Center resources, Technical University of Denmark,
https://doi.org/10.48714/DTU.HPC.0001, 2021. a
EUDP: Predicting wind turbine stability in general inflow PRESTIGE,
https://energiforskning.dk/en/node/15974
(last access: 1 November 2022),
2020. a
García Ramos, N., Sessarego, M., and Horcas, S. G.:
Aero-hydro-servo-elastic coupling of a multi-body finite-element solver and
a multi-fidelity vortex method, Wind Energy, 24, 481–501,
https://doi.org/10.1002/we.2584, 2020. a
Grinderslev, C., Belloni, F., Horcas, S. G., and Sørensen, N. N.: Investigations of aerodynamic drag forces during structural blade testing using high-fidelity fluid–structure interaction, Wind Energ. Sci., 5, 543–560, https://doi.org/10.5194/wes-5-543-2020, 2020a. a
Grinderslev, C., Vijayakumar, G., Ananthan, S., Sørensen, N., Zahle, F., and
Sprague, M.: Validation of blade-resolved computational fluid dynamics for a
MW-scale turbine rotor in atmospheric flow, J. Phys.-Conf.
Ser., 1618, 052049, https://doi.org/10.1088/1742-6596/1618/5/052049,
2020b. a
Grinderslev, C., Horcas, S., and Sørensen, N.: Fluid–structure interaction
simulations of a wind turbine rotor in complex flows, validated through field
experiments, Wind Energy, 24,
1426–1442, https://doi.org/10.1002/we.2639,
2021a. a
Grinderslev, C., Sørensen, N. N., Horcas, S. G., Troldborg, N., and Zahle, F.: Wind turbines in atmospheric flow: fluid–structure interaction simulations with hybrid turbulence modeling, Wind Energ. Sci., 6, 627–643, https://doi.org/10.5194/wes-6-627-2021, 2021b. a
Gritskevich, M. S., Garbaruk, A. V., Schütze, J., and Menter, F. R.:
Development of DDES and IDDES formulations for the k−ω shear stress
transport model, Flow Turbul. Combust., 88, 431–449,
https://doi.org/10.1007/s10494-011-9378-4, 2012. a
Hansen, M. H.: Aeroelastic stability analysis of wind turbines using an
eigenvalue approach, Wind Energy, 7, 133–143,
https://doi.org/10.1002/we.116, 2004. a
Heinz, J., Sørensen, N., and Zahle, F.: Fluid-structure interaction
computations for geometrically resolved rotor simulations using CFD, Wind
Energy, 19, 2205–2221, 2016a. a
Heinz, J., Sørensen, N., Zahle, F., and Skrzypinski, W.: Vortex-induced
vibrations on a modern wind turbine blade, Wind Energy, 19, 2041–2051,
https://doi.org/10.1002/we.1967, 2016b. a, b
Horcas, S., Madsen, M., Sørensen, N., and Zahle, F.: Suppressing Vortex
Induced Vibrations of Wind Turbine Blades with Flaps, in: Recent Advances in
CFD for Wind and Tidal Offshore Turbines, edited by: Ferrer, E. and Montlaur, A., Springer,
11–24, https://doi.org/10.1007/978-3-030-11887-7_2, 2019. a, b, c
Horcas, S., Barlas, T., Zahle, F., and Sørensen, N.: Vortex induced vibrations
of wind turbine blades: Influence of the tip geometry, Phys. Fluids, 32,
065104, https://doi.org/10.1063/5.0004005, 2020. a, b, c, d
Hu, P., Sun, C., Zhu, X., and Du, Z.: Investigations on vortex-induced
vibration of a wind turbine airfoil at a high angle of attack via modal
analysis, J. Renew. Sustain. Ener., 13, 054105,
https://doi.org/10.1063/5.0040509, 2021. a
Koopmann, G. H.: The vortex wakes of vibrating cylinders at low Reynolds
numbers, J. Fluid Mech., 28, 501–512, 1967. a
Larsen, T. and Hansen, A.: How 2 HAWC2, the user's manual, Tech. rep., Risø
National Laboratory, https://orbit.dtu.dk/en/publications/how-2-hawc2-the-users-manual
(last access: 1 November 2022), ISBN 978-87-550-3583-6, 2007. a
Lee, J. H. and Bernitsas, M. M.: High-damping, high-Reynolds VIV tests for
energy harnessing using the VIVACE converter, Ocean Eng., 38,
1697–1712, https://doi.org/10.1016/j.oceaneng.2011.06.007, 2011. a
Lupi, F., Höffer, R., and Niemann, H. J.: Aerodynamic damping in vortex
resonance from aeroelastic wind tunnel tests on a stack, J. Wind
Eng. Ind. Aerod., 208, 104438,
https://doi.org/10.1016/j.jweia.2020.104438, 2021. a
Madsen, H. A., Larsen, T. J., Pirrung, G. R., Li, A., and Zahle, F.: Implementation of the blade element momentum model on a polar grid and its aeroelastic load impact, Wind Energ. Sci., 5, 1–27, https://doi.org/10.5194/wes-5-1-2020, 2020. a
Madsen, H. A., Sørensen, N. N., Bak, C., Troldborg, N., and Pirrung, G.:
Measured aerodynamic forces on a full scale 2 MW turbine in comparison with
EllipSys3D and HAWC2 simulations, J. Phys.-Conf. Ser.,
1037, 022011,
https://doi.org/10.1088/1742-6596/1037/2/022011, 2018. a
Meskell, C. and Pellegrino, A.: Vortex shedding lock-in due to pitching
oscillation of a wind turbine blade section at high angles of attack,
Int. J. Aerospace Eng., 2019, 6919505,
https://doi.org/10.1155/2019/6919505, 2019. a
Michelsen, J.: Basis3D – A Platform for Development of Multiblock PDE Solvers., Tech. rep., Risø National Laboratory, https://backend.orbit.dtu.dk/ws/portalfiles/portal/272917945/Michelsen_J_Basis3D.pdf
(last access: 1 November 2022), 1992. a
Michelsen, J.: Block Structured Multigrid Solution of 2D and 3D Elliptic
PDE's., Tech. rep., Technical University of Denmark, 1994. a
Pavese, C., Wang, Q., Kim, T., Jonkman, J., and Sprague, M.: HAWC2 and BeamDyn:
Comparison Between Beam Structural Models for Aero-Servo-Elastic Frameworks,
in: Proceedings of the EWEA Annual Event and Exhibition 2015, European Wind
Energy Association (EWEA), paper for poster presentation, EWEA Annual
Conference and Exhibition 2015, Paris, France, 17–20 November 2015, NREL/CP-5000-65115, https://www.nrel.gov/docs/fy16osti/65115.pdf
(last access: 1 November 2022), 2015. a
Placzek, A., Sigrist, J. F., and Hamdouni, A.: Numerical simulation of an
oscillating cylinder in a cross-flow at low Reynolds number: Forced and free
oscillations, Comput. Fluids, 38, 80–100,
https://doi.org/10.1016/j.compfluid.2008.01.007, 2009. a
Riva, R., Horcas, S. G., Sørensen, N. N., Grinderslev, C., and Pirrung,
G. R.: Stability analysis of vortex-induced vibrations on wind turbines,
J. Phys.-Conf. Ser., 2265, 042054,
https://doi.org/10.1088/1742-6596/2265/4/042054, 2022. a
Schepers, J. G., Boorsma, K., Madsen, H. A., Pirrung, G. R., Bangga, G., Guma, G., Lutz, T., Potentier, T., Braud, C., Guilmineau, E., Croce, A., Cacciola, S., Schaffarczyk, A. P., Lobo, B. A., Ivanell, S., Asmuth, H., Bertagnolio, F., Sørensen, N. N., Shen, W. Z., Grinderslev, C., Forsting, A. M., Blondel, F., Bozonnet, P., Boisard, R., Yassin, K., Hoening, L., Stoevesandt, B., Imiela, M., Greco, L., Testa, C., Magionesi, F., Vijayakumar, G., Ananthan, S., Sprague, M. A., Branlard, E., Jonkman, J., Carrion, M., Parkinson, S., and Cicirello, E.: IEA Wind TCP Task 29, Phase IV: Detailed Aerodynamics of
Wind Turbines, Zenodo, https://doi.org/10.5281/zenodo.4813068, 2021. a
Shur, M. L., Spalart, P. R., Strelets, M. K., and Travin, A. K.: A hybrid
RANS-LES approach with delayed-DES and wall-modelled LES capabilities,
Int. J. Heat Fluid Fl., 29, 1638–1649,
https://doi.org/10.1016/j.ijheatfluidflow.2008.07.001, 2008.
a
Sørensen, N. and Schreck, S.: Transitional DDES computations of the NREL
Phase-VI rotor in axial flow conditions, J. Phys.-Conf.
Ser., 555, 012096, https://doi.org/10.1088/1742-6596/555/1/012096, 2014. a
Sørensen, N., Zahle, F., Boorsma, K., and Schepers, G.: CFD computations
of the second round of MEXICO rotor measurements, J. Phys.-Conf. Ser., 753, 022054, https://doi.org/10.1088/1742-6596/753/2/022054, 2016. a
Sørensen, N.: General purpose flow solver applied to flow over hills, PhD
thesis, https://backend.orbit.dtu.dk/ws/portalfiles/portal/12280331/Ris_R_827.pdf (last access: 1 November 2022) 1995. a
Sørensen, N.: HypGrid2D. A 2-d mesh generator, Tech. rep., Risø National
Laboratory, https://backend.orbit.dtu.dk/ws/portalfiles/portal/7750949/RIS_R_1035.pdf (last access: 1 November 2022), ISBN 87-550-2368-1, 1998. a
Sørensen, N. N., Michelsen, J. A., and Schreck, S.: Navier–Stokes
predictions of the NREL phase VI rotor in the NASA Ames 80 ft × 120 ft wind
tunnel, Wind Energy, 5, 151–169, https://doi.org/10.1002/we.64, 2002. a
Williamson, C. and Govardhan, R.: Vortex-Induced Vibrations, Annu. Rev. Fluid
Mech., 36, 413–55, https://doi.org/10.1146/annurev.fluid.36.050802.122128, 2004. a
Zhang, M., Song, Y., Wang, J., Abdelkefi, A., Yu, H., and Yu, H.:
Vortex-induced vibration of a circular cylinder with nonlinear stiffness :
prediction using forced vibration data, Nonlinear Dynam., 108, 1867–1884,
https://doi.org/10.1007/s11071-022-07332-7, 2022. a
Download
The requested paper has a corresponding corrigendum published. Please read the corrigendum first before downloading the article.
- Article
(7578 KB) - Full-text XML
Short summary
As wind turbines increase in size, the risk of flow-induced instabilities increases. This study investigates the phenomenon of vortex-induced vibrations (VIVs) on a large 10 MW wind turbine blade using two high-fidelity methods. It is found that VIVs can occur with multiple equilibrium states for the same flow case, showing an dependence on the initial conditions. This means that a blade which is stable in a flow can become unstable if, e.g., a turbine operation provokes an initial vibration.
As wind turbines increase in size, the risk of flow-induced instabilities increases. This study...
Altmetrics
Final-revised paper
Preprint