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Boorsma, K. (author), Schepers, J.G. (author), Madsen, H.A. (author), Pirrung, G. (author), Sorensen, N. (author), Bangga, G. (author), Imiela, M. (author), Grinderslev, C. (author), Forsting, A.M. (author), Shen, W.Z. (author), Croce, A. (author), Cacciola, S. (author), Schafferczyk, A.P. (author), Lobo, B. (author), Blondel, F. (author), Gilbert, P. (author), Boisard, R. (author), Honing, L. (author), Greco, L. (author), Testa, C. (author), Branlard, E. (author), Jonkman, J. (author), Vijayakumar, G. (author)Within the framework of the fourth phase of the International Energy Agency (IEA) Wind Task 29, a large comparison exercise between measurements and aeroelastic simulations has been carried out featuring three simulation cases in axial, sheared and yawed inflow conditions. Results were obtained from more than 19 simulation tools originating from...article 2023
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Mancini, S. (author), Boorsma, K. (author), Schepers, J.G. (author), Savenije, F.J. (author)With the increase in rotor sizes, the implementation of innovative pitch control strategies, and the first floating solutions entering the market, the importance of unsteady aerodynamic phenomena in the operation of modern offshore wind turbines has increased significantly. Including aerodynamic unsteadiness in blade element momentum (BEM)...article 2023
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Vimalakanthan, K. (author), van der Mijle Meijer, H. (author), Bakhmet, I. (author), Schepers, J.G. (author)Leading edge erosion (LEE) is one of the most critical degradation mechanisms that occur with wind turbine blades (WTBs), generally starting from the tip section of the blade. A detailed understanding of the LEE process and the impact on aerodynamic performance due to the damaged leading edge (LE) is required to select the most appropriate...article 2023
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Langidis, A. (author), Petrovic, V. (author), Mancini, S. (author), Boorsma, K. (author), Schepers, J.G. (author), Kühn, M. (author)Dynamic inflow effects occur due to the rapid change of the rotor loading under conditions such as fast pitch steps. The paper presents a setup suitable for the investigation of those effects for non-axisymmetric rotor conditions, namely individual pitch steps. Furthermore, insights into the relevant phenomena are gathered. An individual pitch...conference paper 2023
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- Sahoo, A. (author), Ferreira, C.S. (author), Schepers, J.G. (author), Ravishankara, A.K. (author), Yu, W. (author) public lecture 2023
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Mancini, S. (author), Boorsma, K. (author), Schepers, J.G. (author), Savenije, F.J. (author)With the increase in rotor sizes, the implementation of innovative pitch control strategies, and the first floating solutions entering the market, the importance of unsteady aerodynamic phenomena in the operation of modern offshore wind turbines has increased significantly. Including aerodynamic unsteadiness in Blade Element Momentum (BEM)...article 2022
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Bianchini, A. (author), Bangga, G. (author), Baring-Gould, I. (author), Croce, A. (author), Ignacio Cruz, J. (author), Damiani, R. (author), Erfort, G. (author), Simao Ferreira, C. (author), Infield, D. (author), Nayeri, C.N. (author), Pechivanoglou, G. (author), Runacres, M. (author), Schepers, J.G. (author), Summerville, B. (author), Wood, D. (author), Orrell, A. (author)While modern wind turbines have become by far the largest rotating machines on Earth with further upscaling planned for the future, a renewed interest in small wind turbines (SWTs) is fostering energy transition and smart grid development. Small machines have traditionally not received the same level of aerodynamic refinement as their larger...article 2022
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Berger, F. (author), Neuhaus, L. (author), Onnen, D. (author), Holling, M. (author), Schepers, J.G. (author), Kuhn, M. (author)The dynamic inflow effect describes the unsteady aerodynamic response to fast changes in rotor loading due to the inertia of the wake. Fast changes in turbine loading due to pitch actuation or rotor speed transients lead to load overshoots. The phenomenon is suspected to be also relevant for gust situations; however, this was never shown, and...article 2022
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Hur, C. (author), Ferreira, C. (author), Schepers, J.G. (author)Horizontal axis wind turbines (HAWTs) experience yaw misalignments due to the phy sical limitations of yaw controllers and various novel active yaw controls. Moreover, the motion of floating offshore wind turbines (FOWTs) accelerates yaw misalignment. The blade element mo mentum (BEM) method is widely used due to its computational efficiency for...article 2022
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Sanderse, B. (author), Dighe, V.V. (author), Boorsma, K. (author), Schepers, J.G. (author)This paper presents an efficient strategy for the Bayesian calibration of parameters of aerodynamic wind turbine models. The strategy relies on constructing a surrogate model (based on adaptive polynomial chaos expansions), which is used to perform both parameter selection using global sensitivity analysis and parameter calibration with Bayesian...article 2022
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- Schepers, J.G. (author) public lecture 2022
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Schepers, J.G. (author), Sanderse, B. (author), Carrion, M. (author), Rodriguez, C. (author)The project is carried out by TNO, CWI, DNV-GL and Suzlon within the framework of TKI Wind op Zee and with subsidy from the Ministry of Economic Affairs and Climate, through RVO. The main objective of this project is to develop calibrated aerodynamic models with a quantified level of uncertainty for optimal design of the next generation of...report 2021
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Berger, F. (author), Onnen, D. (author), Schepers, J.G. (author), Kuhn, M. (author)The dynamic inflow effect denotes the unsteady aerodynamic response to fast changes in rotor load ing due to a gradual adaption of the wake. This does lead to load overshoots. The objective of the paper was to increase the understanding of that effect based on pitch step experiments on a 1.8 m diameter model wind turbine, which are performed in...article 2021
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Stoevesandt, B. (author), Schepers, J.G. (author), Sun, Y. (author), Fuglsang, P. (author)Wind turbine aerodynamics remains to be a central field in the development of wind turbines. It comprises several aspects, and methods to be understood really make the best use of it in today’s wind turbine and wind farm development. This chapter gives an overview of all aspects in wind energy aerodynamics covered within this book and the...bookPart 2021
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Schepers, J.G. (author)This chapter discusses several aspects related to engineering methods in wind tur bine design codes. Current engineering models for rotor aerodynamics topic are built around the Blade Element Momentum (BEM) theory. The Blade Element Momentum theory in itself is very basic, e.g., it is derived for two-dimensional, stationary, homogenous, and non...bookPart 2021
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Elgammi, M. (author), Schepers, J.G. (author), Osta-Omar, S. (author)Horizontal axis wind turbines (HAWTs) experience three-dimensional rotational and unsteady aerodynamic phenomena at the rotor blades sections. These highly unsteady three-dimensional effects have a dramatic impact on the aerodynamic load distributions on the blades, in particular, when they occur at high angles of attack due to stall delay and...article 2020
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Neunaber, I. (author), Holling, M. (author), Stevens, R.J.A.M. (author), Schepers, J.G. (author), Peinke, J. (author)Wind turbines are usually clustered in wind farms which causes the downstream turbines to operate in the turbulent wakes of upstream turbines. As turbulence is directly related to increased fatigue loads, knowledge of the turbulence in the wake and its evolution are important. Therefore, the main objective of this study is a comprehensive...article 2020
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Caboni, M. (author), Carrion, M. (author), Rodriquez, C. (author), Schepers, J.G. (author), Boorsma, K. (author), Sanderse, B. (author)The general goal of the work reported in this paper is to gain more confidence when performing blade element momentum (BEM)-based aeroelastic simulations, especially when setting-up sub-models and their parameters. Due to limited or no information, the set-up of these methods is often highly uncertain. To achieve this objective, we have...conference paper 2020
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Schepers, J.G. (author), van Dorp, P. (author), Verzijlbergh, R. (author), Baas, P. (author), Jonker, H. (author)This article describes a study in which the loads are assessed as calculated on a 10 MW wind turbine in response to extreme wind events on the North Sea. The turbine on which the loads are calculated is the 10 MW Reference Wind Turbine as designed in the EU project AVATAR (Sieros, et al., January 2015). The study is carried out within the Dutch...article 2020
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Schepers, J.G. (author), Schreck, S.J. (author)This article reviews the aerodynamic measurement programs on wind turbines that have been performed in the last decades. It is largely based on results from four projects carried out under auspices of the international Energy Agency (IEA), which are denoted as IEA Tasks 14, 18, 20, and 29. The aim of these projects was to collect and analyze...article 2019