Articles | Volume 7, issue 3
https://doi.org/10.5194/wes-7-943-2022
© 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-7-943-2022
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
03 May 2022
Research article |
| 03 May 2022
| 03 May 2022
Experimental investigation of mini Gurney flaps in combination with vortex generators for improved wind turbine blade performance
Jörg Alber
CORRESPONDING AUTHOR
Technische Universität Berlin, Hermann-Föttinger Institut,
Müller-Breslau-Str. 8, 10623 Berlin, Germany
Marinos Manolesos
College of Engineering, Swansea University, Bay Campus, Fabian Way,
Swansea, SA1 8EN, United Kingdom
Guido Weinzierl-Dlugosch
SMART BLADE GmbH, Waldemarstr. 39, 10999 Berlin, Germany
Johannes Fischer
SMART BLADE GmbH, Waldemarstr. 39, 10999 Berlin, Germany
Alexander Schönmeier
Technische Universität Berlin, Hermann-Föttinger Institut,
Müller-Breslau-Str. 8, 10623 Berlin, Germany
Christian Navid Nayeri
Technische Universität Berlin, Hermann-Föttinger Institut,
Müller-Breslau-Str. 8, 10623 Berlin, Germany
Christian Oliver Paschereit
Technische Universität Berlin, Hermann-Föttinger Institut,
Müller-Breslau-Str. 8, 10623 Berlin, Germany
Joachim Twele
Hochschule für Technik und Wirtschaft Berlin, Wilhelminenhofstraße 75A, 12459 Berlin, Germany
Jens Fortmann
Hochschule für Technik und Wirtschaft Berlin, Wilhelminenhofstraße 75A, 12459 Berlin, Germany
Pier Francesco Melani
Università degli Studi di Firenze, Department of Industrial
Engineering (DIEF), Via di Santa Marta 3, 50139 Florence, Italy
Alessandro Bianchini
Università degli Studi di Firenze, Department of Industrial
Engineering (DIEF), Via di Santa Marta 3, 50139 Florence, Italy
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Robert Behrens de Luna, Francesco Papi, David Marten, and Christian Oliver Paschereit
Wind Energ. Sci., 10, 3045–3068, https://doi.org/10.5194/wes-10-3045-2025, https://doi.org/10.5194/wes-10-3045-2025, 2025
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Floating offshore wind turbines make wind resources in deeper waters accessible. However, these systems are more complex and costly than fixed-bottom wind turbines and require further optimization to reduce cost. This study analyzed the effect of aeroelastic modeling fidelity on the design of the floater and the wind turbine controller. The results showed that an increase in fidelity resulted in lighter platforms, influenced controller parameters and led to lower costs overall.
Francesco Papi, Pier Francesco Melani, and Alessandro Bianchini
Wind Energ. Sci. Discuss., https://doi.org/10.5194/wes-2025-257, https://doi.org/10.5194/wes-2025-257, 2025
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The paper presents an open-access database of aerodynamic polars for a wide range of airfoils, relevant for wind turbine design and simulation. It includes lift, drag, and moment coefficients for multiple Reynolds and Mach numbers. Coefficients are computed with CFD for fully turbulent and free transition boundary layers, as well as for a blend of the two. Beyond-stall extrapolation models are calibrated via a number of high-fidelity calculations at various angles of attack in separated flow.
Stefano Cioni, Francesco Papi, Pier Francesco Melani, Alessandro Fontanella, Agnese Firpo, Andrea Giuseppe Sanvito, Giacomo Persico, Vincenzo Dossena, Sara Muggiasca, Marco Belloli, and Alessandro Bianchini
Wind Energ. Sci. Discuss., https://doi.org/10.5194/wes-2025-149, https://doi.org/10.5194/wes-2025-149, 2025
Revised manuscript under review for WES
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A multi-fidelity approach is leveraged to investigate the capabilities of engineering models to capture the wake dynamics of a wind turbine model under imposed motion. Differently from previous studies, many more different operating conditions have investigated, including surge, pitch, yaw and wind-wave misalignment cases; moreover, numerical methos are here consistently applied to the same test cases, which are part of the first experimental round of the NETTUNO project.
Leonardo Pagamonci, Francesco Papi, Gabriel Cojocaru, Marco Belloli, and Alessandro Bianchini
Wind Energ. Sci., 10, 1707–1736, https://doi.org/10.5194/wes-10-1707-2025, https://doi.org/10.5194/wes-10-1707-2025, 2025
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The study presents a critical analysis using wind tunnel experiments and large-eddy simulations aimed at quantifying to what extent turbulence affects the wake structures of a floating turbine undergoing large motions. Analyses show that, whenever realistic turbulence comes into play, only small gains in terms of wake recovery are noticed in comparison to bottom-fixed turbines, suggesting the absence of hypothesized superposition effects between inflow and platform motion.
Alessandro Fontanella, Alberto Fusetti, Stefano Cioni, Francesco Papi, Sara Muggiasca, Giacomo Persico, Vincenzo Dossena, Alessandro Bianchini, and Marco Belloli
Wind Energ. Sci., 10, 1369–1387, https://doi.org/10.5194/wes-10-1369-2025, https://doi.org/10.5194/wes-10-1369-2025, 2025
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This paper investigates the impact of large movements allowed by floating wind turbine foundations on their aerodynamics and wake behavior. Wind tunnel tests with a model turbine reveal that platform motions affect wake patterns and turbulence levels. Insights from these experiments are crucial for optimizing large-scale floating wind farms. The dataset obtained from the experiment is published and can aid in developing simulation tools for floating wind turbines.
Alessandro Fontanella, Stefano Cioni, Francesco Papi, Sara Muggiasca, Alessandro Bianchini, and Marco Belloli
Wind Energ. Sci. Discuss., https://doi.org/10.5194/wes-2025-106, https://doi.org/10.5194/wes-2025-106, 2025
Revised manuscript under review for WES
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This study explores how the movement of floating wind turbines affects nearby turbines. Using wind tunnel experiments, we found that certain motions of an upstream turbine can improve the energy produced by a downstream one and change the forces it experiences. These effects depend on how the turbines are spaced and aligned. Our results show that the motion of floating turbines plays a key role in how future offshore wind farms should be designed and operated.
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
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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
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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.
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
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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.
Robert Behrens de Luna, Sebastian Perez-Becker, Joseph Saverin, David Marten, Francesco Papi, Marie-Laure Ducasse, Félicien Bonnefoy, Alessandro Bianchini, and Christian-Oliver Paschereit
Wind Energ. Sci., 9, 623–649, https://doi.org/10.5194/wes-9-623-2024, https://doi.org/10.5194/wes-9-623-2024, 2024
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A novel hydrodynamic module of QBlade is validated on three floating offshore wind turbine concepts with experiments and two widely used simulation tools. Further, a recently proposed method to enhance the prediction of slowly varying drift forces is adopted and tested in varying met-ocean conditions. The hydrodynamic capability of QBlade matches the current state of the art and demonstrates significant improvement regarding the prediction of slowly varying drift forces with the enhanced 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
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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.
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
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Critical unknowns in the design, manufacturing, and operation of future wind turbine and wind plant systems are articulated, and key research activities are recommended.
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
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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.
Paul Veers, Katherine Dykes, Sukanta Basu, Alessandro Bianchini, Andrew Clifton, Peter Green, Hannele Holttinen, Lena Kitzing, Branko Kosovic, Julie K. Lundquist, Johan Meyers, Mark O'Malley, William J. Shaw, and Bethany Straw
Wind Energ. Sci., 7, 2491–2496, https://doi.org/10.5194/wes-7-2491-2022, https://doi.org/10.5194/wes-7-2491-2022, 2022
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Wind energy will play a central role in the transition of our energy system to a carbon-free future. However, many underlying scientific issues remain to be resolved before wind can be deployed in the locations and applications needed for such large-scale ambitions. The Grand Challenges are the gaps in the science left behind during the rapid growth of wind energy. This article explains the breadth of the unfinished business and introduces 10 articles that detail the research needs.
Alessandro Bianchini, Galih Bangga, Ian Baring-Gould, Alessandro Croce, José Ignacio Cruz, Rick Damiani, Gareth Erfort, Carlos Simao Ferreira, David Infield, Christian Navid Nayeri, George Pechlivanoglou, Mark Runacres, Gerard Schepers, Brent Summerville, David Wood, and Alice Orrell
Wind Energ. Sci., 7, 2003–2037, https://doi.org/10.5194/wes-7-2003-2022, https://doi.org/10.5194/wes-7-2003-2022, 2022
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The paper is part of the Grand Challenges Papers for Wind Energy. It provides a status of small wind turbine technology in terms of technical maturity, diffusion, and cost. Then, five grand challenges that are thought to be key to fostering the development of the technology are proposed. To tackle these challenges, a series of unknowns and gaps are first identified and discussed. Improvement areas are highlighted, within which 10 key enabling actions are finally proposed to the wind community.
Rodrigo Soto-Valle, Stefano Cioni, Sirko Bartholomay, Marinos Manolesos, Christian Navid Nayeri, Alessandro Bianchini, and Christian Oliver Paschereit
Wind Energ. Sci., 7, 585–602, https://doi.org/10.5194/wes-7-585-2022, https://doi.org/10.5194/wes-7-585-2022, 2022
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This paper compares different vortex identification methods to evaluate their suitability to study the tip vortices of a wind turbine. The assessment is done through experimental data from the wake of a wind turbine model. Results show comparability in some aspects as well as significant differences, providing evidence to justify further comparisons. Therefore, this study proves that the selection of the most suitable postprocessing methods of tip vortex data is pivotal to ensure robust results.
Sebastian Perez-Becker, David Marten, and Christian Oliver Paschereit
Wind Energ. Sci., 6, 791–814, https://doi.org/10.5194/wes-6-791-2021, https://doi.org/10.5194/wes-6-791-2021, 2021
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Active trailing edge flaps can potentially enable further increases in wind turbine sizes without the disproportionate increase in loads, thus reducing the cost of wind energy even further. Extreme loads and critical deflections of the turbine blade are design-driving issues that can effectively be reduced by flaps. This paper considers the flap hinge moment as an input sensor for a flap controller that reduces extreme loads and critical deflections of the blade in turbulent wind conditions.
Sirko Bartholomay, Tom T. B. Wester, Sebastian Perez-Becker, Simon Konze, Christian Menzel, Michael Hölling, Axel Spickenheuer, Joachim Peinke, Christian N. Nayeri, Christian Oliver Paschereit, and Kilian Oberleithner
Wind Energ. Sci., 6, 221–245, https://doi.org/10.5194/wes-6-221-2021, https://doi.org/10.5194/wes-6-221-2021, 2021
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This paper presents two methods on how to estimate the lift force that is created by a wing. These methods were experimentally assessed in a wind tunnel. Furthermore, an active trailing-edge flap, as seen on airplanes for example, is used to alleviate fluctuating loads that are created within the employed wind tunnel. Thereby, an active flow control device that can potentially serve on wind turbines to lower fatigue or lower the material used for the blades is examined.
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Short summary
This paper investigates the potentials and the limitations of mini Gurney flaps and their combination with vortex generators for improved rotor blade performance of wind turbines. These small passive add-ons are installed in order to increase the annual energy production by mitigating the effects of both early separation toward the root region and surface erosion toward the tip region of the blade. As such, this study contributes to the reliable and long-term generation of renewable energy.
This paper investigates the potentials and the limitations of mini Gurney flaps and their...
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