Articles | Volume 7, issue 4
https://doi.org/10.5194/wes-7-1551-2022
© 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-7-1551-2022
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
20 Jul 2022
Research article |
| 20 Jul 2022
| 20 Jul 2022
Computational fluid dynamics studies on wind turbine interactions with the turbulent local flow field influenced by complex topography and thermal stratification
Patrick Letzgus
CORRESPONDING AUTHOR
Institute of Aerodynamics and Gas Dynamics, University of Stuttgart, Pfaffenwaldring 21, 70569 Stuttgart, Germany
Giorgia Guma
Institute of Aerodynamics and Gas Dynamics, University of Stuttgart, Pfaffenwaldring 21, 70569 Stuttgart, Germany
Thorsten Lutz
Institute of Aerodynamics and Gas Dynamics, University of Stuttgart, Pfaffenwaldring 21, 70569 Stuttgart, Germany
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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
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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.
Pascal Weihing, Marion Cormier, Thorsten Lutz, and Ewald Krämer
Wind Energ. Sci., 9, 933–962, https://doi.org/10.5194/wes-9-933-2024, https://doi.org/10.5194/wes-9-933-2024, 2024
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This study evaluates different approaches to simulate the near-wake flow of a wind turbine. The test case is in off-design conditions of the wind turbine, where the flow is separated from the blades and therefore very difficult to predict. The evaluation of simulation techniques is key to understand their limitations and to deepen the understanding of the near-wake physics. This knowledge can help to derive new wind farm design methods for yield-optimized farm layouts.
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
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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.
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.
Pradip Zamre and Thorsten Lutz
Wind Energ. Sci., 7, 1661–1677, https://doi.org/10.5194/wes-7-1661-2022, https://doi.org/10.5194/wes-7-1661-2022, 2022
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To get more insight into the influence of the urban-terrain flow on the performance of the rooftop-mounted two-bladed Darrieus vertical-axis wind turbine, scale resolving simulations are performed for a generic wind turbine in realistic terrain under turbulent conditions. It is found that the turbulence and skewed nature of the flow near rooftop locations have a positive impact on the performance of the wind turbine.
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
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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.
Florian Wenz, Judith Langner, Thorsten Lutz, and Ewald Krämer
Wind Energ. Sci., 7, 1321–1340, https://doi.org/10.5194/wes-7-1321-2022, https://doi.org/10.5194/wes-7-1321-2022, 2022
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To get a better understanding of the influence of the terrain flow on the unsteady pressure distributions on the wind turbine surface, a fully resolved turbine was simulated in the complex terrain of Perdigão, Portugal. It was found that the pressure fluctuations at the tower caused by vortex shedding are significantly hampered by the terrain flow, while the pressure fluctuations caused by the blade–tower interaction are hardly changed.
Giorgia Guma, Galih Bangga, Thorsten Lutz, and Ewald Krämer
Wind Energ. Sci., 6, 93–110, https://doi.org/10.5194/wes-6-93-2021, https://doi.org/10.5194/wes-6-93-2021, 2021
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With the increase in installed wind capacity, the rotor diameter of wind turbines is becoming larger and larger, and therefore it is necessary to take aeroelasticity into consideration. At the same time, wind turbines are in reality subjected to atmospheric inflow leading to high wind instabilities and fluctuations. Within this work, a high-fidelity chain is used to analyze the effects of both by the use of models of the same turbine with increasing complexity and technical details.
Simone Mancini, Koen Boorsma, Marco Caboni, Marion Cormier, Thorsten Lutz, Paolo Schito, and Alberto Zasso
Wind Energ. Sci., 5, 1713–1730, https://doi.org/10.5194/wes-5-1713-2020, https://doi.org/10.5194/wes-5-1713-2020, 2020
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This work characterizes the unsteady aerodynamic response of a scaled version of a 10 MW floating wind turbine subjected to an imposed platform motion. The focus has been put on the simple yet significant motion along the wind's direction (surge). For this purpose, different state-of-the-art aerodynamic codes have been used, validating the outcomes with detailed wind tunnel experiments. This paper sheds light on floating-turbine unsteady aerodynamics for a more conscious controller design.
Galih Bangga, Thorsten Lutz, and Matthias Arnold
Wind Energ. Sci., 5, 1037–1058, https://doi.org/10.5194/wes-5-1037-2020, https://doi.org/10.5194/wes-5-1037-2020, 2020
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Robust and accurate dynamic stall modeling remains one of the most difficult tasks in wind turbine load calculations despite its long research effort in the past. The present paper describes a new
second-order dynamic stall model for wind turbine airfoils. The new model is robust and improves the prediction for the aerodynamic forces and their higher-harmonic effects due to vortex shedding but also provides improved predictions for pitching moment and drag.
Levin Klein, Jonas Gude, Florian Wenz, Thorsten Lutz, and Ewald Krämer
Wind Energ. Sci., 3, 713–728, https://doi.org/10.5194/wes-3-713-2018, https://doi.org/10.5194/wes-3-713-2018, 2018
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To get a better understanding of noise emissions from wind turbines at frequencies far below the audible range, simulations with increasing complexity were conducted. Consistent with the literature, it has been found that acoustic emission is dominated by the noise generated when the rotor blades pass the tower. These specific frequencies are less dominant in the structure-borne emission. Considering aerodynamic forces acting on the tower is important for the correct modeling of emissions.
Pascal Weihing, Tim Wegmann, Thorsten Lutz, Ewald Krämer, Timo Kühn, and Andree Altmikus
Wind Energ. Sci., 3, 503–531, https://doi.org/10.5194/wes-3-503-2018, https://doi.org/10.5194/wes-3-503-2018, 2018
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This research poses the question of whether rotor performance can be increased by an optimized design of the nacelle. For this purpose, the main geometrical parameters of the nacelle, such as the diameter, the relative position of the blade and the detailed shape in the junction of the blade, are investigated by means of computational fluid dynamics. By implementing a fairing-type shape in the junction, the detrimental flow separation in the inner part of the rotor could be eliminated.
Annette Claudia Klein, Sirko Bartholomay, David Marten, Thorsten Lutz, George Pechlivanoglou, Christian Navid Nayeri, Christian Oliver Paschereit, and Ewald Krämer
Wind Energ. Sci., 3, 439–460, https://doi.org/10.5194/wes-3-439-2018, https://doi.org/10.5194/wes-3-439-2018, 2018
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The paper describes the experimental and numerical investigation of a model wind turbine with a diameter of 3.0 m in a narrow wind tunnel. The objectives of the study are the provision of validation data, the comparison and evaluation of methods of different fidelity, and the assessment of the influence of wind tunnel walls. It turned out that the accordance between the experimental and numerical results is good, but the wind tunnel walls have to be taken into account for the present setup.
Eva Jost, Annette Fischer, Galih Bangga, Thorsten Lutz, and Ewald Krämer
Wind Energ. Sci., 2, 241–256, https://doi.org/10.5194/wes-2-241-2017, https://doi.org/10.5194/wes-2-241-2017, 2017
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Trailing edge flaps applied to the outer part of a wind turbine rotor blade are a very promising concept to reduce fatigue loads as they are able to increase or decrease the airfoil lift for a given angle of attack. They have been widely researched on 2-D airfoils, but only little is known about their aerodynamic characteristics on 3-D wind turbine rotor blades. The present article addresses this issue.
Related subject area
Thematic area: Wind and the atmosphere | Topic: Wind and turbulence
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Til Kristian Vrana and Harald G. Svendsen
Wind Energ. Sci., 9, 919–932, https://doi.org/10.5194/wes-9-919-2024, https://doi.org/10.5194/wes-9-919-2024, 2024
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We developed new ways to plot comprehensive wind resource maps that show the revenue potential of different locations for future wind power developments. The relative capacity factor is introduced as an indicator showing the expected mean power output. The market value factor is introduced, which captures the expected mean market value relative to other wind parks. The Renewable Energy Complementarity (RECom) index combines the two into a single index, resulting in the RECom map.
Scott Dallas, Adam Stock, and Edward Hart
Wind Energ. Sci., 9, 841–867, https://doi.org/10.5194/wes-9-841-2024, https://doi.org/10.5194/wes-9-841-2024, 2024
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This review presents the current understanding of wind direction variability in the context of control-oriented modelling of wind turbines and wind farms in a manner suitable to a wide audience. Motivation comes from the significant and commonly seen yaw error of horizontal axis wind turbines, which carries substantial negative impacts on annual energy production and the levellised cost of wind energy. Gaps in the literature are identified, and the critical challenges in this area are discussed.
Christoffer Hallgren, Jeanie A. Aird, Stefan Ivanell, Heiner Körnich, Ville Vakkari, Rebecca J. Barthelmie, Sara C. Pryor, and Erik Sahlée
Wind Energ. Sci., 9, 821–840, https://doi.org/10.5194/wes-9-821-2024, https://doi.org/10.5194/wes-9-821-2024, 2024
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Knowing the wind speed across the rotor of a wind turbine is key in making good predictions of the power production. However, models struggle to capture both the speed and the shape of the wind profile. Using machine learning methods based on the model data, we show that the predictions can be improved drastically. The work focuses on three coastal sites, spread over the Northern Hemisphere (the Baltic Sea, the North Sea, and the US Atlantic coast) with similar results for all sites.
Lindsay M. Sheridan, Raghavendra Krishnamurthy, William I. Gustafson Jr., Ye Liu, Brian J. Gaudet, Nicola Bodini, Rob K. Newsom, and Mikhail Pekour
Wind Energ. Sci., 9, 741–758, https://doi.org/10.5194/wes-9-741-2024, https://doi.org/10.5194/wes-9-741-2024, 2024
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In 2020, lidar-mounted buoys owned by the US Department of Energy (DOE) were deployed off the California coast in two wind energy lease areas and provided valuable year-long analyses of offshore low-level jet (LLJ) characteristics at heights relevant to wind turbines. In addition to the LLJ climatology, this work provides validation of LLJ representation in atmospheric models that are essential for assessing the potential energy yield of offshore wind farms.
Eliot Quon
Wind Energ. Sci., 9, 495–518, https://doi.org/10.5194/wes-9-495-2024, https://doi.org/10.5194/wes-9-495-2024, 2024
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Engineering models used to design wind farms generally do not account for realistic atmospheric conditions that can rapidly evolve from minute to minute. This paper uses a first-principles simulation technique to predict the performance of five wind turbines during a wind farm control experiment. Challenges included limited observations and atypical conditions. The simulation accurately predicts the aerodynamics of a turbine when it is situated partially within the wake of an upstream turbine.
Lars Neuhaus, Matthias Wächter, and Joachim Peinke
Wind Energ. Sci., 9, 439–452, https://doi.org/10.5194/wes-9-439-2024, https://doi.org/10.5194/wes-9-439-2024, 2024
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Future wind turbines reach unprecedented heights and are affected by wind conditions that have not yet been studied in detail. With increasing height, a transition to laminar conditions with a turbulent–non-turbulent interface (TNTI) becomes more likely. In this paper, the presence and fractality of this TNTI in the atmosphere are studied. Typical fractalities known from ideal laboratory and numerical studies and a frequent occurrence of the TNTI at heights of multi-megawatt turbines are found.
Sebastiano Stipa, Arjun Ajay, Dries Allaerts, and Joshua Brinkerhoff
Wind Energ. Sci., 9, 297–320, https://doi.org/10.5194/wes-9-297-2024, https://doi.org/10.5194/wes-9-297-2024, 2024
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In the current study, we introduce TOSCA (Toolbox fOr Stratified Convective Atmospheres), an open-source computational fluid dynamics (CFD) tool, and demonstrate its capabilities by simulating the flow around a large wind farm, operating in realistic flow conditions. This is one of the grand challenges of the present decade and can yield better insight into physical phenomena that strongly affect wind farm operation but which are not yet fully understood.
Rebecca Foody, Jacob Coburn, Jeanie A. Aird, Rebecca J. Barthelmie, and Sara C. Pryor
Wind Energ. Sci., 9, 263–280, https://doi.org/10.5194/wes-9-263-2024, https://doi.org/10.5194/wes-9-263-2024, 2024
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Using lidar-derived wind speed measurements at approx. 150 m height at onshore and offshore locations, we quantify the advantages of deploying wind turbines offshore in terms of the amount of electrical power produced and the higher reliability and predictability of the electrical power.
Ronald B. Smith
Wind Energ. Sci., 9, 253–261, https://doi.org/10.5194/wes-9-253-2024, https://doi.org/10.5194/wes-9-253-2024, 2024
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Recent papers have investigated the impact of turbine drag on local wind patterns, but these studies have not given a full explanation of the induced pressure field. The pressure field blocks and deflects the wind and in other ways modifies farm efficiency. Current gravity wave models are complex and provide no estimation tools. We dig deeper into the cause of the pressure field and provide approximate closed-form expressions for pressure field effects.
Cédric Raibaudo, Jean-Christophe Gilloteaux, and Laurent Perret
Wind Energ. Sci., 8, 1711–1725, https://doi.org/10.5194/wes-8-1711-2023, https://doi.org/10.5194/wes-8-1711-2023, 2023
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The work presented here proposes interfacing experimental measurements performed in a wind tunnel with simulations conducted with the aeroelastic code FAST and applied to a floating wind turbine model under wave-induced motion. FAST simulations using experiments match well with those obtained using the inflow generation method provided by TurbSim. The highest surge motion frequencies show a significant decrease in the mean power produced by the turbine and a mitigation of the flow dynamics.
Oscar García-Santiago, Andrea N. Hahmann, Jake Badger, and Alfredo Peña
Wind Energ. Sci. Discuss., https://doi.org/10.5194/wes-2023-124, https://doi.org/10.5194/wes-2023-124, 2023
Revised manuscript accepted for WES
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We studied how good the representation of wind farms in weather models is by comparing two popular and simpler methods with a detailed simulation. Our results showed that while these simple methods can predict certain aspects well, they have limitations in specific scenarios. For instance, they can accurately predict wind speed changes in certain areas but might struggle in others. Ultimately, our goal was to make wind farm predictions more reliable and beneficial for the energy sector.
Christoffer Hallgren, Jeanie A. Aird, Stefan Ivanell, Heiner Körnich, Rebecca J. Barthelmie, Sara C. Pryor, and Erik Sahlée
Wind Energ. Sci., 8, 1651–1658, https://doi.org/10.5194/wes-8-1651-2023, https://doi.org/10.5194/wes-8-1651-2023, 2023
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Low-level jets (LLJs) are special types of non-ideal wind profiles affecting both wind energy production and loads on a wind turbine. However, among LLJ researchers, there is no consensus regarding which definition to use to identify these profiles. In this work, we compare two different ways of identifying the LLJ – the falloff definition and the shear definition – and argue why the shear definition is better suited to wind energy applications.
Dan Houck, Nathaniel de Velder, David Maniaci, and Brent Houchens
Wind Energ. Sci. Discuss., https://doi.org/10.5194/wes-2023-130, https://doi.org/10.5194/wes-2023-130, 2023
Revised manuscript accepted for WES
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Experiments offer incredible value to science but results must come with an uncertainty quantification to be meaningful. We present a method to simulate a proposed experiment, calculate uncertainties, and determine the measurement duration (total time of measurements) and the experiment duration (total time to collect the required measurement data when including condition variability and time when measurement is not occurring) required to produce statistically significant and converged results.
Serkan Kartal, Sukanta Basu, and Simon J. Watson
Wind Energ. Sci., 8, 1533–1551, https://doi.org/10.5194/wes-8-1533-2023, https://doi.org/10.5194/wes-8-1533-2023, 2023
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Peak wind gust is a crucial meteorological variable for wind farm planning and operations. Unfortunately, many wind farms do not have on-site measurements of it. In this paper, we propose a machine-learning approach (called INTRIGUE, decIsioN-TRee-based wInd GUst Estimation) that utilizes numerous inputs from a public-domain reanalysis dataset, generating long-term, site-specific peak wind gust series.
Nikolas Angelou, Jakob Mann, and Camille Dubreuil-Boisclair
Wind Energ. Sci., 8, 1511–1531, https://doi.org/10.5194/wes-8-1511-2023, https://doi.org/10.5194/wes-8-1511-2023, 2023
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This study presents the first experimental investigation using two nacelle-mounted wind lidars that reveal the upwind and downwind conditions relative to a full-scale floating wind turbine. We find that in the case of floating wind turbines with small pitch and roll oscillating motions (< 1°), the ambient turbulence is the main driving factor that determines the propagation of the wake characteristics.
Julian Quick, Pierre-Elouan Rethore, Mads Mølgaard Pedersen, Rafael Valotta Rodrigues, and Mikkel Friis-Møller
Wind Energ. Sci., 8, 1235–1250, https://doi.org/10.5194/wes-8-1235-2023, https://doi.org/10.5194/wes-8-1235-2023, 2023
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Wind turbine positions are often optimized to avoid wake losses. These losses depend on atmospheric conditions, such as the wind speed and direction. The typical optimization scheme involves discretizing the atmospheric inputs, then considering every possible set of these discretized inputs in every optimization iteration. This work presents stochastic gradient descent (SGD) as an alternative, which randomly samples the atmospheric conditions during every optimization iteration.
Sarah J. Ollier and Simon J. Watson
Wind Energ. Sci., 8, 1179–1200, https://doi.org/10.5194/wes-8-1179-2023, https://doi.org/10.5194/wes-8-1179-2023, 2023
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This modelling study shows that topographic trapped lee waves (TLWs) modify flow behaviour and power output in offshore wind farms. We demonstrate that TLWs can substantially alter the wind speeds at individual wind turbines and effect the power output of the turbine and whole wind farm. The impact on wind speeds and power is dependent on which part of the TLW wave cycle interacts with the wind turbines and wind farm. Positive and negative impacts of TLWs on power output are observed.
Khaled Yassin, Arne Helms, Daniela Moreno, Hassan Kassem, Leo Höning, and Laura J. Lukassen
Wind Energ. Sci., 8, 1133–1152, https://doi.org/10.5194/wes-8-1133-2023, https://doi.org/10.5194/wes-8-1133-2023, 2023
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The current turbulent wind field models stated in the IEC 61400-1 standard underestimate the probability of extreme changes in wind velocity. This underestimation can lead to the false calculation of extreme and fatigue loads on the turbine. In this work, we are trying to apply a random time-mapping technique to one of the standard turbulence models to adapt to such extreme changes. The turbulent fields generated are compared with a standard wind field to show the effects of this new mapping.
Mark Kelly and Maarten Paul van der Laan
Wind Energ. Sci., 8, 975–998, https://doi.org/10.5194/wes-8-975-2023, https://doi.org/10.5194/wes-8-975-2023, 2023
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The turning of the wind with height, which is known as veer, can affect wind turbine performance. Thus far meteorology has only given idealized descriptions of veer, which has not yet been related in a way readily usable for wind energy. Here we derive equations for veer in terms of meteorological quantities and provide practically usable forms in terms of measurable shear (change in wind speed with height). Flow simulations and measurements at turbine heights support these developments.
Moritz Gräfe, Vasilis Pettas, Julia Gottschall, and Po Wen Cheng
Wind Energ. Sci., 8, 925–946, https://doi.org/10.5194/wes-8-925-2023, https://doi.org/10.5194/wes-8-925-2023, 2023
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Inflow wind field measurements from nacelle-based lidar systems offer great potential for different applications including turbine control, load validation and power performance measurements. On floating wind turbines nacelle-based lidar measurements are affected by the dynamic behavior of the floating foundations. Therefore, the effects on lidar wind speed measurements induced by floater dynamics must be well understood. A new model for quantification of these effects is introduced in our work.
Robin Marcille, Maxime Thiébaut, Pierre Tandeo, and Jean-François Filipot
Wind Energ. Sci., 8, 771–786, https://doi.org/10.5194/wes-8-771-2023, https://doi.org/10.5194/wes-8-771-2023, 2023
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A novel data-driven method is proposed to design an optimal sensor network for the reconstruction of offshore wind resources. Based on unsupervised learning of numerical weather prediction wind data, it provides a simple yet efficient method for the siting of sensors, outperforming state-of-the-art methods for this application. It is applied in the main French offshore wind energy development areas to provide guidelines for the deployment of floating lidars for wind resource assessment.
Wei Fu, Alessandro Sebastiani, Alfredo Peña, and Jakob Mann
Wind Energ. Sci., 8, 677–690, https://doi.org/10.5194/wes-8-677-2023, https://doi.org/10.5194/wes-8-677-2023, 2023
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Nacelle lidars with different beam scanning locations and two types of systems are considered for inflow turbulence estimations using both numerical simulations and field measurements. The turbulence estimates from a sonic anemometer at the hub height of a Vestas V52 turbine are used as references. The turbulence parameters are retrieved using the radial variances and a least-squares procedure. The findings from numerical simulations have been verified by the analysis of the field measurements.
Daniel Hatfield, Charlotte Bay Hasager, and Ioanna Karagali
Wind Energ. Sci., 8, 621–637, https://doi.org/10.5194/wes-8-621-2023, https://doi.org/10.5194/wes-8-621-2023, 2023
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Wind observations at heights relevant to the operation of modern offshore wind farms, i.e. 100 m and more, are required to optimize their positioning and layout. Satellite wind retrievals provide observations of the wind field over large spatial areas and extensive time periods, yet their temporal resolution is limited and they are only representative at 10 m height. Machine-learning models are applied to lift these satellite winds to higher heights, directly relevant to wind energy purposes.
Anna von Brandis, Gabriele Centurelli, Jonas Schmidt, Lukas Vollmer, Bughsin' Djath, and Martin Dörenkämper
Wind Energ. Sci., 8, 589–606, https://doi.org/10.5194/wes-8-589-2023, https://doi.org/10.5194/wes-8-589-2023, 2023
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We propose that considering large-scale wind direction changes in the computation of wind farm cluster wakes is of high relevance. Consequently, we present a new solution for engineering modeling tools that accounts for the effect of such changes in the propagation of wakes. The new model is evaluated with satellite data in the German Bight area. It has the potential to reduce uncertainty in applications such as site assessment and short-term power forecasting.
Oliver Maas
Wind Energ. Sci., 8, 535–556, https://doi.org/10.5194/wes-8-535-2023, https://doi.org/10.5194/wes-8-535-2023, 2023
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The study compares small vs. large wind farms regarding the flow and power output with a turbulence-resolving simulation model. It shows that a large wind farm (90 km length) significantly affects the wind direction and that the wind speed is higher in the large wind farm wake. Both wind farms excite atmospheric gravity waves that also affect the power output of the wind farms.
Regis Thedin, Eliot Quon, Matthew Churchfield, and Paul Veers
Wind Energ. Sci., 8, 487–502, https://doi.org/10.5194/wes-8-487-2023, https://doi.org/10.5194/wes-8-487-2023, 2023
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We investigate coherence and correlation and highlight their importance for disciplines like wind energy structural dynamic analysis, in which blade loading and fatigue depend on turbulence structure. We compare coherence estimates to those computed using a model suggested by international standards. We show the differences and highlight additional information that can be gained using large-eddy simulation, further improving analytical coherence models used in synthetic turbulence generators.
Sheng-Lun Tai, Larry K. Berg, Raghavendra Krishnamurthy, Rob Newsom, and Anthony Kirincich
Wind Energ. Sci., 8, 433–448, https://doi.org/10.5194/wes-8-433-2023, https://doi.org/10.5194/wes-8-433-2023, 2023
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Turbulence intensity is critical for wind turbine design and operation as it affects wind power generation efficiency. Turbulence measurements in the marine environment are limited. We use a model to derive turbulence intensity and test how sea surface temperature data may impact the simulated turbulence intensity and atmospheric stability. The model slightly underestimates turbulence, and improved sea surface temperature data reduce the bias. Error with unrealistic mesoscale flow is identified.
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
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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.
Frédéric Blondel
Wind Energ. Sci., 8, 141–147, https://doi.org/10.5194/wes-8-141-2023, https://doi.org/10.5194/wes-8-141-2023, 2023
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Accurate wind farm flow predictions based on analytical wake models are crucial for wind farm design and layout optimization. Wake superposition methods play a key role and remain a substantial source of uncertainty. In the present work, a momentum-conserving superposition method is extended to the superposition of super-Gaussian-type velocity deficit models, allowing the full wake velocity deficit estimation and design of closely packed wind farms.
Abdul Haseeb Syed, Jakob Mann, Andreas Platis, and Jens Bange
Wind Energ. Sci., 8, 125–139, https://doi.org/10.5194/wes-8-125-2023, https://doi.org/10.5194/wes-8-125-2023, 2023
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Wind turbines extract energy from the incoming wind flow, which needs to be recovered. In very large offshore wind farms, the energy is recovered mostly from above the wind farm in a process called entrainment. In this study, we analyzed the effect of atmospheric stability on the entrainment process in large offshore wind farms using measurements recorded by a research aircraft. This is the first time that in situ measurements are used to study the energy recovery process above wind farms.
Kartik Venkatraman, Trond-Ola Hågbo, Sophia Buckingham, and Knut Erik Teigen Giljarhus
Wind Energ. Sci., 8, 85–108, https://doi.org/10.5194/wes-8-85-2023, https://doi.org/10.5194/wes-8-85-2023, 2023
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This paper is focused on the impact of modeling different effects, such as forest canopy and Coriolis forces, on the wind resource over a complex terrain site located near Perdigão, Portugal. A numerical model is set up and results are compared with field measurements. The results show that including a forest canopy improves the predictions close to the ground at some locations on the site, while the model with inflow from a precursor performed better at other locations.
Ishaan Sood, Elliot Simon, Athanasios Vitsas, Bart Blockmans, Gunner C. Larsen, and Johan Meyers
Wind Energ. Sci., 7, 2469–2489, https://doi.org/10.5194/wes-7-2469-2022, https://doi.org/10.5194/wes-7-2469-2022, 2022
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In this work, we conduct a validation study to compare a numerical solver against measurements obtained from the offshore Lillgrund wind farm. By reusing a previously developed inflow turbulent dataset, the atmospheric conditions at the wind farm were recreated, and the general performance trends of the turbines were captured well. The work increases the reliability of numerical wind farm solvers while highlighting the challenges of accurately representing large wind farms using such solvers.
Xiaoli Guo Larsén and Søren Ott
Wind Energ. Sci., 7, 2457–2468, https://doi.org/10.5194/wes-7-2457-2022, https://doi.org/10.5194/wes-7-2457-2022, 2022
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A method is developed for calculating the extreme wind in tropical-cyclone-affected water areas. The method is based on the spectral correction method that fills in the missing wind variability to the modeled time series, guided by best track data. The paper provides a detailed recipe for applying the method and the 50-year winds of equivalent 10 min temporal resolution from 10 to 150 m in several tropical-cyclone-affected regions.
Yulong Ma, Cristina L. Archer, and Ahmadreza Vasel-Be-Hagh
Wind Energ. Sci., 7, 2407–2431, https://doi.org/10.5194/wes-7-2407-2022, https://doi.org/10.5194/wes-7-2407-2022, 2022
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Wind turbine wakes are important because they reduce the power production of wind farms and may cause unintended impacts on the weather around wind farms. Weather prediction models, like WRF and MPAS, are often used to predict both power and impacts of wind farms, but they lack an accurate treatment of wind farm wakes. We developed the Jensen wind farm parameterization, based on the existing Jensen model of an idealized wake. The Jensen parameterization is accurate and computationally efficient.
Andrea N. Hahmann, Oscar García-Santiago, and Alfredo Peña
Wind Energ. Sci., 7, 2373–2391, https://doi.org/10.5194/wes-7-2373-2022, https://doi.org/10.5194/wes-7-2373-2022, 2022
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We explore the changes in wind energy resources in northern Europe using output from simulations from the Climate Model Intercomparison Project (CMIP6) under the high-emission scenario. Our results show that climate change does not particularly alter annual energy production in the North Sea but could affect the seasonal distribution of these resources, significantly reducing energy production during the summer from 2031 to 2050.
Turið Poulsen, Bárður A. Niclasen, Gregor Giebel, and Hans Georg Beyer
Wind Energ. Sci., 7, 2335–2350, https://doi.org/10.5194/wes-7-2335-2022, https://doi.org/10.5194/wes-7-2335-2022, 2022
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Wind power is cheap and environmentally friendly, but it has a disadvantage: it is a variable power source. Because wind is not blowing everywhere simultaneously, optimal placement of wind farms can reduce the fluctuations.
This is explored for a small isolated area. Combining wind farms reduces wind power fluctuations for timescales up to 1–2 d. By optimally placing four wind farms, the hourly fluctuations are reduced by 15 %. These wind farms are located distant from each other.
Graziela Luzia, Andrea N. Hahmann, and Matti Juhani Koivisto
Wind Energ. Sci., 7, 2255–2270, https://doi.org/10.5194/wes-7-2255-2022, https://doi.org/10.5194/wes-7-2255-2022, 2022
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This paper presents a comprehensive validation of time series produced by a mesoscale numerical weather model, a global reanalysis, and a wind atlas against observations by using a set of metrics that we present as requirements for wind energy integration studies. We perform a sensitivity analysis on the numerical weather model in multiple configurations, such as related to model grid spacing and nesting arrangements, to define the model setup that outperforms in various time series aspects.
Xiaodong Zhang and Anand Natarajan
Wind Energ. Sci., 7, 2135–2148, https://doi.org/10.5194/wes-7-2135-2022, https://doi.org/10.5194/wes-7-2135-2022, 2022
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Joint probability distribution of 10 min mean wind speed and the standard deviation is proposed using the Gaussian mixture model and has been shown to agree well with 15 years of measurements. The environmental contour with a 50-year return period (extreme turbulence) is estimated. The results from the model could be taken as inputs for structural reliability analysis and uncertainty quantification of wind turbine design loads.
Alex Rybchuk, Timothy W. Juliano, Julie K. Lundquist, David Rosencrans, Nicola Bodini, and Mike Optis
Wind Energ. Sci., 7, 2085–2098, https://doi.org/10.5194/wes-7-2085-2022, https://doi.org/10.5194/wes-7-2085-2022, 2022
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Numerical weather prediction models are used to predict how wind turbines will interact with the atmosphere. Here, we characterize the uncertainty associated with the choice of turbulence parameterization on modeled wakes. We find that simulated wind speed deficits in turbine wakes can be significantly sensitive to the choice of turbulence parameterization. As such, predictions of future generated power are also sensitive to turbulence parameterization choice.
Lindsay M. Sheridan, Raghu Krishnamurthy, Gabriel García Medina, Brian J. Gaudet, William I. Gustafson Jr., Alicia M. Mahon, William J. Shaw, Rob K. Newsom, Mikhail Pekour, and Zhaoqing Yang
Wind Energ. Sci., 7, 2059–2084, https://doi.org/10.5194/wes-7-2059-2022, https://doi.org/10.5194/wes-7-2059-2022, 2022
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Using observations from lidar buoys, five reanalysis and analysis models that support the wind energy community are validated offshore and at rotor-level heights along the California Pacific coast. The models are found to underestimate the observed wind resource. Occasions of large model error occur in conjunction with stable atmospheric conditions, wind speeds associated with peak turbine power production, and mischaracterization of the diurnal wind speed cycle in summer months.
Sebastian Brune and Jan D. Keller
Wind Energ. Sci., 7, 1905–1918, https://doi.org/10.5194/wes-7-1905-2022, https://doi.org/10.5194/wes-7-1905-2022, 2022
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A post-processing of the wind speed of the regional reanalysis COSMO-REA6 in Central Europe is performed based on a combined physical and statistical approach. The physical basis is provided by downscaling wind speeds with the help of a diagnostic wind model, which reduces the horizontal grid point spacing by a factor of 8. The statistical correction using a neural network based on different variables of the reanalysis leads to an improvement of 30 % in RMSE compared to COSMO-REA6.
Rieska Mawarni Putri, Etienne Cheynet, Charlotte Obhrai, and Jasna Bogunovic Jakobsen
Wind Energ. Sci., 7, 1693–1710, https://doi.org/10.5194/wes-7-1693-2022, https://doi.org/10.5194/wes-7-1693-2022, 2022
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As offshore wind turbines' sizes are increasing, thorough knowledge of wind characteristics in the marine atmospheric boundary layer (MABL) is becoming crucial to help improve offshore wind turbine design and reliability. The present study discusses the wind characteristics at the first offshore wind farm, Vindeby, and compares them with the wind measurements at the FINO1 platform. Consistent wind characteristics are found between Vindeby measurements and the FINO1 measurements.
Pradip Zamre and Thorsten Lutz
Wind Energ. Sci., 7, 1661–1677, https://doi.org/10.5194/wes-7-1661-2022, https://doi.org/10.5194/wes-7-1661-2022, 2022
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To get more insight into the influence of the urban-terrain flow on the performance of the rooftop-mounted two-bladed Darrieus vertical-axis wind turbine, scale resolving simulations are performed for a generic wind turbine in realistic terrain under turbulent conditions. It is found that the turbulence and skewed nature of the flow near rooftop locations have a positive impact on the performance of the wind turbine.
Eduardo Weide Luiz and Stephanie Fiedler
Wind Energ. Sci., 7, 1575–1591, https://doi.org/10.5194/wes-7-1575-2022, https://doi.org/10.5194/wes-7-1575-2022, 2022
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This work analyses a meteorological event, called nocturnal low-level jets (NLLJs), defined as high wind speeds relatively close to the surface. There were positive and negative impacts from NLLJs. While NLLJs increased the mean power production, they also increased the variability in the wind with height. Our results imply that long NLLJ events are also larger, affecting many wind turbines at the same time. Short NLLJ events are more local, having stronger effects on power variability.
Niels Troldborg, Søren J. Andersen, Emily L. Hodgson, and Alexander Meyer Forsting
Wind Energ. Sci., 7, 1527–1532, https://doi.org/10.5194/wes-7-1527-2022, https://doi.org/10.5194/wes-7-1527-2022, 2022
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This article shows that the power performance of a wind turbine may be very different in flat and complex terrain. This is an important finding because it shows that the power output of a given wind turbine is governed by not only the available wind at the position of the turbine but also how the ambient flow develops in the region behind the turbine.
Sarah Barber, Alain Schubiger, Sara Koller, Dominik Eggli, Alexander Radi, Andreas Rumpf, and Hermann Knaus
Wind Energ. Sci., 7, 1503–1525, https://doi.org/10.5194/wes-7-1503-2022, https://doi.org/10.5194/wes-7-1503-2022, 2022
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In this work, a range of simulations are carried out with seven different wind modelling tools at five different complex terrain sites and the results compared to wind speed measurements at validation locations. This is then extended to annual energy production (AEP) estimations (without wake effects), showing that wind profile prediction accuracy does not translate directly or linearly to AEP accuracy. It is therefore vital to consider overall AEP when evaluating simulation accuracies.
Louis de Montera, Henrick Berger, Romain Husson, Pascal Appelghem, Laurent Guerlou, and Mauricio Fragoso
Wind Energ. Sci., 7, 1441–1453, https://doi.org/10.5194/wes-7-1441-2022, https://doi.org/10.5194/wes-7-1441-2022, 2022
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A novel method for estimating offshore wind resources at turbine hub height with synthetic aperture radar (SAR) satellites is presented. The machine learning algorithm uses as input geometrical parameters of the SAR sensors and parameters related to atmospheric stability. It is trained with Doppler wind lidar vertical profiles. The extractable wind power accuracy up to 200 m is within 3 %, and SAR can resolve the coastal wind gradient, unlike the Weather Research and Forecasting numerical mode.
Florian Wenz, Judith Langner, Thorsten Lutz, and Ewald Krämer
Wind Energ. Sci., 7, 1321–1340, https://doi.org/10.5194/wes-7-1321-2022, https://doi.org/10.5194/wes-7-1321-2022, 2022
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To get a better understanding of the influence of the terrain flow on the unsteady pressure distributions on the wind turbine surface, a fully resolved turbine was simulated in the complex terrain of Perdigão, Portugal. It was found that the pressure fluctuations at the tower caused by vortex shedding are significantly hampered by the terrain flow, while the pressure fluctuations caused by the blade–tower interaction are hardly changed.
Rad Haghi and Curran Crawford
Wind Energ. Sci., 7, 1289–1304, https://doi.org/10.5194/wes-7-1289-2022, https://doi.org/10.5194/wes-7-1289-2022, 2022
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Based on the IEC standards, a limited number of simulations is sufficient to calculate the extreme and fatigue loads on a wind turbine. However, this means inaccuracy in the output statistics. This paper aims to build a surrogate model on blade element momentum aerodynamic model simulation output employing non-intrusive polynomial chaos expansion. The surrogate model is then used in a large number of Monte Carlo simulations to provide an accurate statistical estimate of the loads.
Beatriz Cañadillas, Maximilian Beckenbauer, Juan J. Trujillo, Martin Dörenkämper, Richard Foreman, Thomas Neumann, and Astrid Lampert
Wind Energ. Sci., 7, 1241–1262, https://doi.org/10.5194/wes-7-1241-2022, https://doi.org/10.5194/wes-7-1241-2022, 2022
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Scanning lidar measurements combined with meteorological sensors and mesoscale simulations reveal the strong directional and stability dependence of the wake strength in the direct vicinity of wind farm clusters.
Cited articles
Abkar, M., Sharifi, A., and Porté-Agel, F.: Wake Flow in a Wind Farm during a Diurnal Cycle, J. Turbul., 17, 1–22,
https://doi.org/10.1080/14685248.2015.1127379, 2016. a
Bangga, G., Weihing, P., Lutz, T., and Krämer, E.: Effect of computational
grid on accurate prediction of a wind turbine rotor using delayed
detached-eddy simulations, J. Mech. Sci. Technol., 31, 2359–2364, https://doi.org/10.1007/s12206-017-0432-6, 2017. a
Barber, S., Schubiger, A., Koller, S., Eggli, D., Radi, A., Rumpf, A., and Knaus, H.: The wide range of factors contributing to Wind Resource Assessment accuracy in complex terrain, Wind Energ. Sci. Discuss. [preprint], https://doi.org/10.5194/wes-2021-158, in review, 2022. a, b, c
Barthelmie, R., Pryor, S., Wildmann, N., and Menke, R.: Wind Turbine Wake
Characterization in Complex Terrain via integrated Doppler Lidar Data from
the Perdigão Experiment, J. Phys. Conf. Ser., 1037,
052022, https://doi.org/10.1088/1742-6596/1037/5/052022, 2018. a
Bechmann, A. and Sørensen, N. N.: Hybrid RANS/LES Method for Wind Flow over
Complex Terrain, Wind Energy, 13, 36–50,
https://doi.org/10.1002/we.346, 2010. a
Belcher, S., Harman, I., and Finnigan, J.: The Wind in the Willows: Flows in
Forest Canopies in Complex Terrain, Annu. Rev. Fluid Mech., 44,
479–504, https://doi.org/10.1146/annurev-fluid-120710-101036, 2012. a, b
Benek, J. A., Steger, J. L., Dougherty, F. C., and Buning, P. G.: Chimera, A
Grid-Embedding Technique, Tech. Arnold Engineering
Development Center, 7th Computational Physics Conference
15–17 July 1985, Cincinnati, OH, USA, AEDC-TR-85-64, https://doi.org/10.2514/6.1985-1523, 1986. a
Berge, K. z., Schoen, M., Mauz, M., Platis, A., Kesteren, B. v., Leukauf, D.,
El Bahlouli, A., Letzgus, P., Knaus, H., and Bange, J.: A Two-Day Case
Study: Comparison of Turbulence Data from an Unmanned Aircraft System with a
Model Chain for Complex Terrain, Bound.-Lay. Meteorol., 180, 53–78,
https://doi.org/10.1007/s10546-021-00608-2, 2021. a
Brodeur, P. and Masson, C.: Numerical Site Calibration over Complex Terrain, J. Sol. Energ., 130, 031020,
https://doi.org/10.1115/1.2931502, 2008. a
Churchfield, M. J., Lee, S., and Moriarty, P. J.: Adding Complex Terrain and
Stable Atmospheric Condition Capability to the OpenFOAM-based Flow Solver of
the Simulator for On/Offshore Wind Farm Applications (SOWFA), ITM Web Conf., 2, 02001, https://doi.org/10.1051/itmconf/20140202001, 2014. a
Desmond, C. J., Watson, S. J., and Hancock, P. E.: Modelling the Wind Energy
Resource in Complex Terrain and Atmospheres. Numerical Simulation and Wind
Tunnel Investigation of non-Neutral Forest Canopy Flow, J. Wind
Eng. Ind. Aerod., 166, 48–60,
https://doi.org/10.1016/j.jweia.2017.03.014, 2017. a, b
Dupont, S. and Patton, E.: Influence of stability and seasonal canopy changes
on micrometeorology within and above an orchard canopy: The CHATS experiment, Agr. Forest Meteorol., 157, 11–29,
https://doi.org/10.1016/j.agrformet.2012.01.011, 2012. a
Dupont, S., Brunet, Y., and Finnigan, J. J.: Large-Eddy Simulation of
Turbulent Flow over a Forested Hill: Validation and Coherent Structure
Identification, Q. J. Roy. Meteor. Soc., 134, 1911–1929, https://doi.org/10.1002/qj.328, 2008. a
El Bahlouli, A., Leukauf, D., Platis, A., zum Berge, K., Bange, J., and Knaus,
H.: Validating CFD Predictions of Flow over an Escarpment Using Ground-Based
and Airborne Measurement Devices, Energies, 13, 4688, https://doi.org/10.3390/en13184688, 2020. a
Finnigan, J., Ayotte, K., Harman, I., Katul, G., Oldroyd, H., Patton, E.,
Poggi, D., Ross, A., and Taylor, P.: Boundary-Layer Flow Over Complex
Topography, Bound.-Lay. Meteorol., 177, 247–313,
https://doi.org/10.1007/s10546-020-00564-3, 2020. a
Foken, T.: 50 Years of the Monin–Obukhov Similarity Theory, Bound.-Lay. Meteorol., 119, 431–447, https://doi.org/10.1007/s10546-006-9048-6, 2006. a
ForstBW: Schwäbische Alb,
https://www.forstbw.de/wald-im-land/zahlenwunder/strukturen/wuchsgebiete/schwaebische-alb/,
last access: 23 February 2021. a
Gryning, S.-E., Batchvarova, E., Brümmer, B., Jørgensen, H., and Larsen, S.:
On the extension of the wind profile over homogeneous terrain beyond the
surface layer, Bound.-Lay. Meteorol., 124, 251–268,
https://doi.org/10.1007/s10546-007-9166-9, 2007. a, b
Guma, G., Bangga, G., Schwarz, E., Lutz, T., and Krämer, E.: Consistent 3 D CFD
and BEM simulations of a research turbine considering rotational
augmentation, J. Phys. Conf. Ser., 1037, 022024,
https://doi.org/10.1088/1742-6596/1037/2/022024, 2018. a
Guma, G., Bangga, G., Lutz, T., and Krämer, E.: Aeroelastic analysis of wind turbines under turbulent inflow conditions, Wind Energ. Sci., 6, 93–110, https://doi.org/10.5194/wes-6-93-2021, 2021. a
Hanazaki, H. and Hunt, J. C. R.: Structure of unsteady stably stratified
turbulence with mean shear, J. Fluid Mech., 507, 1–42,
https://doi.org/10.1017/S0022112004007888, 2004. a
Ivanell, S., Arnqvist, J., Avila, M., Cavar, D., Chavez-Arroyo, R. A., Olivares-Espinosa, H., Peralta, C., Adib, J., and Witha, B.: Micro-scale model comparison (benchmark) at the moderately complex forested site Ryningsnäs, Wind Energ. Sci., 3, 929–946, https://doi.org/10.5194/wes-3-929-2018, 2018. a
Jameson, A.: Time Dependent Calculations using Multigrid, with Applications to Unsteady Flows past Airfoils and Wings, AIAA paper, 10th Computational Fluid Dynamics Conference, 24–26 June 1991, Honolulu, HI, USA, 1596,
https://doi.org/10.2514/6.1991-1596, 1991. a
Kelly, M.: From standard wind measurements to spectral characterization: turbulence length scale and distribution, Wind Energ. Sci., 3, 533–543, https://doi.org/10.5194/wes-3-533-2018, 2018. a, b
Kelly, M. and Gryning, S.-E.: Long-Term Mean Wind Profiles Based on Similarity Theory, Bound.-Lay. Meteorol., 136, 377–390,
https://doi.org/10.1007/s10546-010-9509-9, 2010. a
Kelly, M., Larsen, G., Dimitrov, N., and Natarajan, A.: Probabilistic
Meteorological Characterization for Turbine Loads, J. Phys. Conf. Ser., 524, 012 076, https://doi.org/10.1088/1742-6596/524/1/012076, 2014. a, b
Kroll, N., Rossow, C.-C., Becker, K., and Thiele, F.: The MEGAFLOW Project,
Aerosp. Sci. Technol., 4, 223–237,
https://doi.org/10.1016/S1270-9638(00)00131-0, 2000. a
Lalic, B. and Mihailovic, D.: An Empirical Relation Describing Leaf-Area
Density inside the Forest for Environmental Modeling, J. Appl. Meteorol., 43, 641–645,
https://doi.org/10.1175/1520-0450(2004)043<0641:AERDLD>2.0.CO;2, 2004. a
Letzgus, P., Lutz, T., and Krämer, E.: Detached Eddy Simulations of the local
Atmospheric Flow Field within a Forested Wind Energy Test Site located in
Complex Terrain, J. Phys. Conf. Ser., 1037, 072043,
https://doi.org/10.1088/1742-6596/1037/7/072043, 2018. a, b, c
Letzgus, P., Bahlouli, A. E., Leukauf, D., Hofsäß, M., Lutz, T., and
Krämer, E.: Microscale CFD Simulations of a Wind Energy Test Site in the
Swabian Alps with Mesoscale Based Inflow Data, J. Phys. Conf. Ser., 1618, 062021, https://doi.org/10.1088/1742-6596/1618/6/062021, 2020. a, b, c, d
Mann, J.: The spatial structure of neutral atmospheric surface layer
turbulence, J. Fluid Mech., 273, 141–168,
https://doi.org/10.1017/S0022112094001886, 1994. a, b, c, d
Mann, J.: Wind field simulation, Probabilistic Engineering Mechanics, 13,
269–282, https://doi.org/10.1016/S0266-8920(97)00036-2, 1998. a
Menter, F.: Two-Equation Eddy-Viscosity Turbulence Models for Engineering
Applications, AIAA journal, 32, 1598–1605,
https://doi.org/10.2514/3.12149, 1994. a
Müller, J., Lutz, T., and Krämer, E.: Numerical Simulation of the Swept FNG
Wing in Atmospheric Turbulence, AIAA Aviation 2020 FORUM, 15–19 June 2020, Virtual Event, AIAA 2020-2778, https://doi.org/10.2514/6.2020-2778, 2020. a
Murphy, P., Lundquist, J. K., and Fleming, P.: How wind speed shear and directional veer affect the power production of a megawatt-scale operational wind turbine, Wind Energ. Sci., 5, 1169–1190, https://doi.org/10.5194/wes-5-1169-2020, 2020. a
Peña, A., Gryning, S.-E., and Mann, J.: On the Length-Scale of the Wind
profile, Q. J. Roy. Meteor. Soc., 136, 2119–2131, https://doi.org/10.1002/qj.714, 2010. a, b, c, d
Radünz, W. C., Sakagami, Y., Haas, R., Petry, A. P., Passos, J. C.,
Miqueletti, M., and Dias, E.: Influence of Atmospheric Stability on Wind
Farm Performance in Complex Terrain, Appl. Energ., 282, 116149,
https://doi.org/10.1016/j.apenergy.2020.116149, 2021. a
Ross, A.: Large-eddy Simulations of Flow Over Forested Ridges, Bound.-Lay. Meteorol., 128, 59–76, https://doi.org/10.1007/s10546-008-9278-x, 2008. a
Sathe, A., Mann, J., Barlas, T., Bierbooms, W., and van Bussel, G.: Influence
of atmospheric stability on wind turbine loads, Wind Energy, 16, 1013–1032, https://doi.org/10.1002/we.1528, 2013. a, b, c
Schäferlein, U., Keßler, M., and Krämer, E.: High Order CFD-Simulation of
the Rotor-Fuselage Interaction, 39th European Rotorcraft Forum, 37–39,
ISBN 9781510810075, 2013. a
Schulz, C., Hofsäß, M., Anger, J., Rautenberg, A., Lutz, T., Cheng,
P. W., and Bange, J.: Comparison of Different Measurement Techniques and a
CFD Simulation in Complex Terrain, J. Phys. Conf. Ser.,
753, 082017, https://doi.org/10.1088/1742-6596/753/8/082017, 2016.
a, b
Shaw, R. H. and Schumann, U.: Large-eddy Simulation of Turbulent Flow above
and within a Forest, Bound.-Lay. Meteorol., 61, 47–64,
https://doi.org/10.1007/BF02033994, 1992. a
Sogachev, A., Kelly, M., and LeClerc, M.: Consistent Two-Equation Closure
Modelling for Atmospheric Research: Buoyancy and Vegetation Implementations,
Bound.-Lay. Meteorol., 145, 307–327, https://doi.org/10.1007/s10546-012-9726-5, 2012. a
Sørensen, N. 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
Troldborg, N., Sørensen, J., Mikkelsen, R., and Sørensen, N.: A Simple
Atmospheric Boundary Layer Model applied to Large Eddy Simulation of Wind
Turbine Wakes, Wind Energy, 17, 657–669, https://doi.org/10.1002/we.1608, 2014. a, b
Van der Hoven, I.: Power Spectrum of Horizontal Wind Speed in the Frequency
Range from 0.0007 to 900 Cycles per Hour, Journal of Atmospheric Sciences,
14, 160–164, https://doi.org/10.1175/1520-0469(1957)014<0160:PSOHWS>2.0.CO;2,
1957. a
Wegley, H. L., Ramsdell, J. V., Orgill, M. M., and Drake, R. L.: Siting
Handbook for Small Wind Energy Conversion Systems, Battelle Pacific
Northwest Labs., Richland, WA, USA, 5490541, https://doi.org/10.2172/5490541, 1980. a
Weihing, P.: Numerical Study of Transition, Flow Separation and Wake Phenomena of Wind Turbines with Enhanced Hybrid RANS/LES Methods, Dissertation, ISBN 978-3-8439-4772-5, 2020. a
Weihing, P., Letzgus, J., Bangga, G., Lutz, T., and Krämer, E.: Hybrid
RANS/LES Capabilities of the Flow Solver FLOWer – Application to Flow Around
Wind Turbines, Progress in Hybrid RANS-LES Modelling, 137, 369–380,
https://doi.org/10.1007/978-3-319-70031-1_31, 2016. a
Weihing, P., Letzgus, J., Bangga, G., Lutz, T., and Krämer, E.: Hybrid
RANS/LES capabilities of the flow solver FLOWer-Application to flow around
wind turbines, Progress in Hybrid RANS-LES Modelling, 137, 369–380, https://doi.org/10.1007/978-3-319-70031-1_31, 2018. a, b
Wyngaard, J. C.: Turbulence in the Atmosphere, Cambridge University Press,
https://doi.org/10.1017/CBO9780511840524, 2010. a
Short summary
The research article presents the results of a study of highly resolved numerical simulations of a wind energy test site in complex terrain that is currently under construction in the Swabian Alps in southern Germany. The numerical results emphasised the importance of considering orography, vegetation, and thermal stratification in numerical simulations to resolve the wind field decently. In this way, the effects on loads, power, and wake of the wind turbine can also be predicted well.
The research article presents the results of a study of highly resolved numerical simulations of...
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