Effects of vortex generators on a blunt trailing-edge airfoil for wind turbines

Gao, Linyue; Zhang, Hui; Liu, Yongqian; Han, Soonhung

doi:10.1016/j.renene.2014.11.043

Cited by 127 publications

(66 citation statements)

References 17 publications

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“…In the work carried out by Gao et al [16] and Baldacchino et al [17] on a 30% thick DU97-W-300 airfoil (Delft University of Technology, Delft, The Nederlands), the maximum lift coefficient was substantially increased due to the implementation of passive VGs. When the angle of attack increases, both lift and drag coefficients rise up to values higher than the ones reached in steady state conditions.…”

Section: Introductionmentioning

confidence: 99%

Computational Modelling of Rectangular Sub-Boundary Layer Vortex Generators

et al. 2018

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Vortex generators (VGs) are increasingly used in the wind turbine manufacture industry as flow control devices to improve rotor blade aerodynamic performance. Nevertheless, VGs may produce excess residual drag in some applications. The so-called sub-boundary layer VGs can provide an effective flow-separation control with lower drag than the conventional VGs. The main objective of this study is to investigate how well the simulations can reproduce the physics of the flow of the primary vortex generated by rectangular sub-boundary layer VGs mounted on a flat plate with a negligible pressure gradient with an angle of attack of the vane to the oncoming flow of β = 18 • . Three devices with aspect ratio values of 2, 2.5 and 3 are qualitatively and quantitatively compared. To that end, computational simulations have been carried out using the RANS (Reynolds averaged Navier-Stokes) method and at Reynolds number Re = 2600 based on the boundary layer momentum thickness θ at the VG position. The computational results show good agreement with the experimental data provided by the Advanced Aerodynamic Tools of Large Rotors (AVATAR) European project for the development and validation of aerodynamic models. Finally, the results indicate that the highest VG seems to be more suitable for separation control applications.

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Section: Introductionmentioning

confidence: 99%

Computational Modelling of Rectangular Sub-Boundary Layer Vortex Generators

et al. 2018

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“…Oye [162] studied the effect of VG on the performance of 1 MW rated capacity wind turbine and reported that the addition of VGs to the rotor blades significantly improved the performance of the turbine. To explore the extent of reduction in drag achieved using the VG, it was compared without VG numerically by Gao et al [163] taking into consideration a three-dimensional model which accurately predicts the rotating condition of the turbine blade. VG jets are the streams of fluid that enter through the wall of the blade in a cross flow direction and create a dominant streamwise vortex that stays in the boundary layer causing the flow to stick to the surface, Khan and Johnston [164].…”

Section: Active Flow Control Techniquesmentioning

confidence: 99%

Horizontal Axis Wind Turbine Blade Design Methodologies for Efficiency Enhancement—A Review

et al. 2018

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Among renewable sources of energy, wind is the most widely used resource due to its commercial acceptance, low cost and ease of operation and maintenance, relatively much less time for its realization from concept till operation, creation of new jobs, and least adverse effect on the environment. The fast technological development in the wind industry and availability of multi megawatt sized horizontal axis wind turbines has further led the promotion of wind power utilization globally. It is a well-known fact that the wind speed increases with height and hence the energy output. However, one cannot go above a certain height due to structural and other issues. Hence other attempts need to be made to increase the efficiency of the wind turbines, maintaining the hub heights to acceptable and controllable limits. The efficiency of the wind turbines or the energy output can be increased by reducing the cut-in-speed and/or the rated-speed by modifying and redesigning the blades. The problem is tackled by identifying the optimization parameters such as annual energy yield, power coefficient, energy cost, blade mass, and blade design constraints such as physical, geometric, and aerodynamic. The present paper provides an overview of the commonly used models, techniques, tools and experimental approaches applied to increase the efficiency of the wind turbines. In the present review work, particular emphasis is made on approaches used to design wind turbine blades both experimental and numerical, methodologies used to study the performance of wind turbines both experimentally and analytically, active and passive techniques used to enhance the power output from wind turbines, reduction in cut-in-speed for improved wind turbine performance, and lastly the research and development work related to new and efficient materials for the wind turbines.

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“…Great care is also needed to be taken in Fernandez-Gamiz et al [10] and Urkiola et al [11] studied the behaviour of a rectangular VG on a flat plate and the streamwise vortices produced to investigate how the physics of the wake behind VGs in a negligible streamwise pressure gradient flow can be reproduced in CFD simulations. In the work carried by Gao et al [12] on a 30% thick DU97-W-300 airfoil (Delft University family airfoils, Delft, The Netherlands), the maximum lift coefficient was increased from 1.5 to approximately 2 due to the implementation of passive VGs. When the angle of attack increases, both the lift and drag coefficients rise to values higher than the ones reached in the steady state conditions.…”

Section: Introductionmentioning

confidence: 99%

Five Megawatt Wind Turbine Power Output Improvements by Passive Flow Control Devices

et al. 2017

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Abstract:The effects of two types of flow control devices, vortex generators (VGs) and Gurney flaps (GFs), on the power output performance of a multi-megawatt horizontal axis wind turbine is presented. To that end, an improved blade element momentum (BEM)-based solver has been developed and BEM-based computations have been carried out on the National Renewable Energy Laboratory (NREL) 5 MW baseline wind turbine. The results obtained from the clean wind turbine are compared with the ones obtained from the wind turbine equipped with the flow control devices. A significant increase in the average wind turbine power output has been found for all of the flow control device configurations and for the wind speed realizations studied in the present work. Furthermore, a best configuration case is proposed which has the largest increase of the average power output. In that case, increments on the average power output of 10.4% and 3.5% have been found at two different wind speed realizations. The thrust force and bending moment in the root of the blade have also been determined and compared with the values of the clean wind turbine. A residual increase in the bending moment of less than 1% has been found.

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Effects of vortex generators on a blunt trailing-edge airfoil for wind turbines

Cited by 127 publications

References 17 publications

Computational Modelling of Rectangular Sub-Boundary Layer Vortex Generators

Computational Modelling of Rectangular Sub-Boundary Layer Vortex Generators

Horizontal Axis Wind Turbine Blade Design Methodologies for Efficiency Enhancement—A Review

Five Megawatt Wind Turbine Power Output Improvements by Passive Flow Control Devices

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