Computational investigations of blunt trailing‐edge and twist modifications to the inboard region of the NREL 5 MW rotor

Chow, Raymond; Dam, C. P. van

doi:10.1002/we.1505

Cited by 13 publications

(6 citation statements)

References 26 publications

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“…In the horizontal axis wind turbine context, in [16] is shown by means of CFD that modifying the TE thickness distribution of a rotor can improve its performance characteristics such as efficiency and stability while still maintaining safety standards set forth by regulatory bodies. More recently, the effects of modifications to twist and TE on aerodynamic characteristics of a rotor by means of CFD were investigated [17]. They conclude that increasing TE thickness leads to an increased thrust, however, this additional load is primarily concentrated at the inboard region, causing a small rise in root bending moments.…”

Section: Introductionmentioning

confidence: 99%

Computational investigation of the effect of the trailing edge thickness on the wind turbine performance

Echenique,

Puertolas,

Amo

2024

J. Phys.: Conf. Ser.

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Trailing edge (TE) thickness is a manufacturing constraint in blade design, especially for airfoils with a sharp TE. To achieve a specific TE thickness, blade geometry is often modified during the design process, typically in the outer zone of the blade where the airfoil’s TE is thinner. This area has a significant impact on energy production and loads. Quantifying the effect of TE thickness modifications is crucial for making informed design decisions. Therefore, this study quantifies and compares the impact of linear and polynomial geometry modifications on airfoil aerodynamics and turbine performance. Xfoil and OpenFAST were used to calculate these performance variations in the well-known NREL 5 MW wind turbine. The TE thickness of the model was modified to meet various manufacturing constraints, ranging from no restriction to a limit of 12mm TE thickness. In terms of the aerodynamic behavior of the airfoils, the maximum efficiency of airfoils with low relative thickness decreases as the TE thickness increases. Annual Energy Production shows a reduction of up to 0.42% for the worst case, while blade root loads increase by up to 20%. For low relative thickness airfoils, the linear method has proven to be a better option with less impact on performance.

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Section: Introductionmentioning

confidence: 99%

Computational investigation of the effect of the trailing edge thickness on the wind turbine performance

Echenique,

Puertolas,

Amo

2024

J. Phys.: Conf. Ser.

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“…Standish et al [12] symmetrically increased the thickness of an airfoil on both sides of the airfoil mid-curve through an exponential mixing function method that does not change the maximum thickness of the original airfoil and the centerline distribution. Chow et al [13] found that blunt trailing-edge modification can not only provide a number of structural advantages, such as increasing the cross-section area and inertia moment of bend for a given maximum thickness and chord, but it also produces a great improvement in the lift coefficient and reduces the sensitivity to surface soiling. Baker [14] analyzed airfoils with a symmetric blunt trailing-edge thickness through the experimental method.…”

Section: Introductionmentioning

confidence: 99%

Aerodynamic Performance Analysis of a Modified Joukowsky Airfoil: Parametric Control of Trailing Edge Thickness

et al. 2021

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In order to ensure the blade strength of large-scale wind turbine, the blunt trailing edge airfoil structure is proposed, aiming at assessing the impact of the trailing edge shape on the flow characteristics and airfoil performance. In this paper, a Joukowsky airfoil is modified by adding the tail thickness parameter K to achieve the purpose of accurately modifying the thickness of the blunt tail edge of the airfoil. Using Ansys Fluent as a tool, a large eddy simulation (LES) model was used to analyze the vortex structure of the airfoil trailing edge. The attack angles were used as variables to analyze the aerodynamic performance of airfoils with different K-values. It was found that when α = 0°, α = 4°, and α = 8°, the lift coefficient and lift–drag ratio increased with increasing K-value. With the increase in the angle of attack from 8° to 12°, the lift–drag ratio of the airfoil with the blunt tail increased from +70% to −7.3% compared with the original airfoil, which shows that the airfoil with the blunt trailing edge has a better aerodynamic performance at a small angle of attack. The aerodynamic characteristics of the airfoil are affected by the periodic shedding of the wake vortex and also have periodic characteristics. By analyzing the vortex structure at the trailing edge, it was found that the value of K can affect the size of the vortex and the position of vortex generation/shedding. When α = 0°, α = 4°, and α = 8°, the blunt trailing edge could improve the aerodynamic performance of the airfoil; when α = 12°, the position of vortex generation changed, which reduced the aerodynamic performance of the airfoil. Therefore, when designing the trailing edge of an airfoil, the thickness of the trailing edge can be designed according to the specific working conditions. It can provide valuable information for the design and optimization of blunt trailing edge airfoil.

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“…Guntur (2013) numerically studied the MEXICO rotor with inboard twist modifications and found that the trailing vortices, which is caused by the change in the span-wise loading, results in an effect similar to that typically observed near the blade tip. Chow and van Dam (2012) investigated the effects of twist modifications in the inner area of the 5 MW rotor. The study focused on wind speed of 11m/s, at the knee of the power curve.…”

Section: Introductionmentioning

confidence: 99%

Numerical Study of Effect of Blade Twist Modifications on the Aerodynamic Performance of Wind Turbine

Beabpimai

Chitsomboon

2019

Int. J. Renew. Energy Dev.

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This paper aims to investigate aerodynamic performance of a wind turbine blade with twist modifications using computational fluid dynamics (CFD). The phenomenon of 3D stall-delay effect in relation to blade twist is the key feature to be investigated in order to improve efficiency of a wind turbine. The NREL (National Renewable Energy Laboratory) Phase VI wind turbine rotor was used for validation and as the baseline rotor. The baseline blade geometry was modified by increasing/decreasing the twist angles in the inboard, mid-board and outboard regions of the blade in the form of a symmetrical curve with maximum twist angle of 3°. The steady incompressible Reynolds-averaged Navier-Stokes (RANS) equations with the k-ω Shear Stress Transport (SST) turbulence closure model were used for the calculations at wind speeds ranging from 5-20 m/s. The computational results for the baseline Phase VI rotor were validated against experimental data and a good agreement was found. The computational results for the modified blades were compared against those of the baseline blade. It was found that increase of annual energy production of up to 5.1% could be achieved by this modification technique. ©2019. CBIORE-IJRED. All rights reserved

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Computational investigations of blunt trailing‐edge and twist modifications to the inboard region of the NREL 5 MW rotor

Cited by 13 publications

References 26 publications

Computational investigation of the effect of the trailing edge thickness on the wind turbine performance

Computational investigation of the effect of the trailing edge thickness on the wind turbine performance

Aerodynamic Performance Analysis of a Modified Joukowsky Airfoil: Parametric Control of Trailing Edge Thickness

Numerical Study of Effect of Blade Twist Modifications on the Aerodynamic Performance of Wind Turbine

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