Characterization of the carborundum used in rough airfoil surface tests and modelling with CFD

Méndez, Beatriz; Muñoz, Arturo; Pires, Oscar; Munduate, Xabier

doi:10.2514/6.2017-0916

Cited by 2 publications

(3 citation statements)

References 6 publications

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“…It is important to remark that for all roughness states, no correlation is used in this study between the emulated roughness height and a roughness height found in a real wind turbine. The scientific community is researching this correlation [25], [23], [24]. The relatively higher value of k s /c of the 30% thick airfoil, is combined with larger chords at the mid-span region of the blade.…”

Section: Roughness Emulation 30% Thick Airfoilmentioning

confidence: 99%

Induced stalled flow due to roughness sensitivity for thick airfoils in modern wind turbines

Gutierrez

Llorente

Ragni

2022

J. Phys.: Conf. Ser.

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The mid-span region of wind turbine blades can be thickened to fulfil the structural requirements of the blade. Hence, thick airfoils, that were designed to operate at the root region of the blade, are moved to the mid-span region. This could not imply remarkable variations of the blade performance once its surface is smooth. However, the sensitivity of thick airfoils to roughness could cause significant aerodynamic impacts such as flow separation. This research aims to quantify the impact of the blade thickness, under smooth and rough conditions, in the annual energy production and the fatigue loads of the blade. Ten blade designs, linearly interpolated in thickness, are studied employing aero-elastic computations. The results reveal that the thickest blade increases the annual energy production by 5% with respect to the thinnest blade under rough conditions. Whereas this increase is less than 1% under smooth conditions. The loss of annual energy production varies with the blade thickness linearly for thin blades while it varies exponentially for thick blades up to 22%. Fatigue loads assessment confirmed a reduction of the damage equivalent load under smooth conditions, whereas the thickest blade increased it 28% under rough conditions.

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Section: Roughness Emulation 30% Thick Airfoilmentioning

confidence: 99%

Induced stalled flow due to roughness sensitivity for thick airfoils in modern wind turbines

Gutierrez

Llorente

Ragni

2022

J. Phys.: Conf. Ser.

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“…WMB is an in-house compressible code developed and validated by CENER and the University of Liverpool for 2D and 3D aerodynamics analysis of WTs. This code has been used to characterize the effect of distributed roughness located in the aerofoil surface on aerofoil performance [2][3][4][5][6]. The code is capable of analysing compressible, RANS or URANS equations.…”

Section: Numerical Set-upmentioning

confidence: 99%

“…The aerodynamic profile of a blade of a wind turbine (WT) can be altered because of erosion or dirt, which can lead to losses in the annual energy production (AEP) [1][2][3][4][5]. Some studies estimated that such losses can be up to 4% for erosion and 24% for dirt [6][7][8]. Erosion has been identified as one of the largest WT problems globally and several projects, which involve blade manufacturers (OEM), research centres, material suppliers and WT operators, are focused on understanding erosion mechanism, prediction of the lifetime of coatings, development of new materials/systems for leading edge protection (LEP), erosion detection/monitoring, and reduction of erosion impact on the operational performance [9][10][11][12][13].…”

Section: Introductionmentioning

confidence: 99%

Effect of erosion morphology on wind turbine production losses

Saenz

Mendez

Muñoz

2022

J. Phys.: Conf. Ser.

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The impact of wind turbine (WT) blade erosion is still a major issue today because of the associated high maintenance costs and the loss of power production. The erosion process is influenced by many physical phenomena that still need to be understood better. Especially WT manufactures and owners need to know the potential impact of different levels of blade erosion on annual energy production (AEP). The damage produced by erosion modifies the aerofoil shape and therefore its aerodynamic properties, resulting in an AEP drop. In this study, the effect of various morphologies of erosion on AEP was obtained. First, a 3D characterisation of eroded blades using a laser scanner was performed. The erosion damages were grouped into two typologies: Typology 1 covers pits and gouges, and Typology 2 covers extended loss of top coat. Based on this, 2D section geometries were defined to evaluate the effect of erosion on the aerofoil aerodynamic 2D properties, which was done using the CFD code WMB. The aerofoil used as a reference was DU96W180. It was determined that the erosion damage alters the aerodynamic behaviour of the aerofoil by reducing the Cl max and the slope of the Cl- α curve, which resulted in a drop of the aerodynamic efficiency from 40% to 72%. These detrimental effects increased depending on the damage location (i.e., pressure side and closeness to the leading edge), damage size and shape (i.e., sharp transitions from the eroded to non-eroded surfaces). To evaluate the erosion effect on the AEP, the NREL 5 MW WT was selected. All its components were kept except the last 30% outer section of the 61.5 m blade whose NACA64_A17 aerofoil was replaced by a DU96W180. The erosion damages were modelled by extending the 2D eroded geometry along this outer section. The AEP was calculated using BLADED 4.5. It was concluded that erosion resulted in a decrease of the AEP, which can be up to 1% and 6% for damages of Typology 1 and 2, respectively. This study will help to standardize and estimate the effect of the type of erosion on AEP losses for different shapes and erosion typologies.

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Characterization of the carborundum used in rough airfoil surface tests and modelling with CFD

Cited by 2 publications

References 6 publications

Induced stalled flow due to roughness sensitivity for thick airfoils in modern wind turbines

Induced stalled flow due to roughness sensitivity for thick airfoils in modern wind turbines

Effect of erosion morphology on wind turbine production losses

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