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1
Zhao, Li Hua, Ming Liu, Tie Lv, and Xiao Qun Mei. "Numerical Simulation of Vertical Axis Wind Turbine Blade Airfoil Performance." Applied Mechanics and Materials 529 (June 2014): 173–77. http://dx.doi.org/10.4028/www.scientific.net/amm.529.173.
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Research of blade airfoil aerodynamic characteristics is an important foundation for the vertical axis wind turbine aerodynamic design and performance analysis. CFD simulation software has been applied in this paper. Representative lift-type vertical axis wind turbine airfoil NACA0014, NACA2414, NACA4414, NACA6414, NACA8414 's aerodynamic simulation have been studied. Camber airfoil relative with the change in to the flow velocity is analyzed. At different angles of attack effect on the aerodynamic performance of wind turbines, variation of parameters for airfoil aerodynamic had been analyzed. It will help the optimal design of airfoils for vertical axis wind turbines.
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Khalil, Yassine, Lhoussaine Tenghiri, Farid Abdi, and Anas Bentamy. "Improvement of aerodynamic performance of a small wind turbine." Wind Engineering 44, no. 1 (May 23, 2019): 21–32. http://dx.doi.org/10.1177/0309524x19849847.
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The aerodynamic performance of horizontal-axis wind turbines is strongly dependent on many parameters, among which the airfoil type and the blade geometry (mainly defined by the chord and the twist distributions) are considered the most critical ones. In this article, an approach giving the appropriate airfoil for a small wind turbine design was conducted by performing an aerodynamic improvement of the blade’s airfoil. First, a preliminary design of the rotor blades of a small wind turbine (11 kW) was conducted using the small wind turbine rotor design code. This preliminary approach was done for different airfoils, and it resulted in a maximum power coefficient of 0.40. Then, the aerodynamic efficiency of the wind turbine was improved by modifying the geometry of the airfoils. This technique targets the optimization of the lift-to-drag ratio (Cl/Cd) of the airfoil within a range of angles of attack. Also, a non-uniform rational B-spline approximation of the airfoil was adopted in order to reduce the number of the design variables of the optimization. This methodology determined the best airfoil for the design of a small wind turbine, and it gave an improved power coefficient of 0.42.
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Maleki Dastjerdi, Sajad, Kobra Gharali, Armughan Al-Haq, and Jatin Nathwani. "Application of Simultaneous Symmetric and Cambered Airfoils in Novel Vertical Axis Wind Turbines." Applied Sciences 11, no. 17 (August 30, 2021): 8011. http://dx.doi.org/10.3390/app11178011.
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Two novel four-blade H-darrieus vertical axis wind turbines (VAWTs) have been proposed for enhancing self-start capability and power production. The two different airfoil types for the turbines are assessed: a cambered S815 airfoil and a symmetric NACA0018 airfoil. For the first novel wind turbine configuration, the Non-Similar Airfoils 1 (NSA-1), two NACA0018 airfoils, and two S815 airfoils are opposite to each other. For the second novel configuration (NSA-2), each of the S815 airfoils is opposite to one NACA0018 airfoil. Using computational fluid dynamics (CFD) simulations, static and dynamic conditions are evaluated to establish self-starting ability and the power coefficient, respectively. Dynamic stall investigation of each blade of the turbines shows that NACA0018 under dynamic stall impacts the turbine’s performance and the onset of dynamic stall decreases the power coefficient of the turbine significantly. The results show that NSA-2 followed by NSA-1 has good potential to improve the self-starting ability (13.3%) compared to the turbine with symmetric airfoils called HT-NACA0018. In terms of self-starting ability, NSA-2 not only can perform in about 66.67% of 360° similar to the wind turbine with non-symmetric airfoils (named HT-S815) but the power coefficient of NSA-2 at the design tip speed ratio of 2.5 is also 4.5 times more than the power coefficient of HT-S815; the power coefficient difference between HT-NACA0018 and HT-S815 (=0.231) is decreased significantly when HT-S815 is replaced by NSA-2 (=0.076). These novel wind turbines are also simple.
4
Chen, Jin, Jiang Tao Cheng, and Wen Zhong Shen. "Research on Design Methods and Aerodynamics Performance of CQU-DTU-B21 Airfoil." Advanced Materials Research 455-456 (January 2012): 1486–90. http://dx.doi.org/10.4028/www.scientific.net/amr.455-456.1486.
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This paper presents the design methods of CQU-DTU-B21 airfoil for wind turbine. Compared with the traditional method of inverse design, the new method is described directly by a compound objective function to balance several conflicting requirements for design wind turbine airfoils, which based on design theory of airfoil profiles, blade element momentum (BEM) theory and airfoil Self-Noise prediction model. And then an optimization model with the target of maximum power performance on a 2D airfoil and low noise emission of design ranges for angle of attack has been developed for designing CQU-DTU-B21 airfoil. To validate the optimization results, the comparison of the aerodynamics performance by XFOIL and wind tunnels test respectively at Re=3×106 is made between the CQU-DTU-B21 and DU93-W-210 which is widely used in wind turbines.
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Yi, Mei, Qu Jianjun, and Li Yan. "Airfoil Design for Vertical Axis Wind Turbine Operating at Variable Tip Speed Ratios." Open Mechanical Engineering Journal 9, no. 1 (October 7, 2015): 1007–16. http://dx.doi.org/10.2174/1874155x01509011007.
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A new airfoil design method for H type vertical axis wind turbine is introduced in the present study. A novel indicator is defined to evaluate vertical axis wind turbine aerodynamic performance at variable tip speed ratios and selected as the airfoil design objective. A mathematic model describing the relationship between airfoil design variables and objective is presented for direct airfoil design on the basis of regression design theory. The aerodynamic performance simulation is conducted by computational fluid dynamics approach validated by a wind tunnel test in the study. Based on the newly developed mathematic model, a new airfoil is designed for a given wind turbine model under constant wind speed of 8 m/s. Meanwhile, the comparison of aerodynamic performance for newly designed airfoil and existing vertical axis wind turbine airfoils is studied. It has been demonstrated that, by the novel indicator, the rotor aerodynamic performance at variable tip speed ratios with the newly designed airfoil is 6.78% higher than the one with NACA0015 which is the airfoil widely used in commercial H type vertical axis wind turbine.
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Tian, Weijun, Zhen Yang, Qi Zhang, Jiyue Wang, Ming Li, Yi Ma, and Qian Cong. "Bionic Design of Wind Turbine Blade Based on Long-Eared Owl’s Airfoil." Applied Bionics and Biomechanics 2017 (2017): 1–10. http://dx.doi.org/10.1155/2017/8504638.
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The main purpose of this paper is to demonstrate a bionic design for the airfoil of wind turbines inspired by the morphology of Long-eared Owl’s wings. Glauert Model was adopted to design the standard blade and the bionic blade, respectively. Numerical analysis method was utilized to study the aerodynamic characteristics of the airfoils as well as the blades. Results show that the bionic airfoil inspired by the airfoil at the 50% aspect ratio of the Long-eared Owl’s wing gives rise to a superior lift coefficient and stalling performance and thus can be beneficial to improving the performance of the wind turbine blade. Also, the efficiency of the bionic blade in wind turbine blades tests increases by 12% or above (up to 44%) compared to that of the standard blade. The reason lies in the bigger pressure difference between the upper and lower surface which can provide stronger lift.
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Wu, Guo Qing, Xinghua Chen, Yang Cao, and Jing Ling Zhou. "Simulation and Test for Two Airfoils with Wind Guide Vane of VAWT." Advanced Materials Research 148-149 (October 2010): 1199–203. http://dx.doi.org/10.4028/www.scientific.net/amr.148-149.1199.
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Two airfoils of vertical axis wind turbine (VAWT) were designed, and the wind guide vane was added for VAWT. By using Fluent and the environment wind tunnel, some results were simulated and tested for two different types of airfoils and its wind guide vane. The performance data on certain condition was obtained. Research showed that utilization of wind energy with guide vane wind turbine was higher than those without guide vane structure. The performance of airfoil was more excellent than airfoil . Wind guide vane structure is a new structure for wind turbine which will have a wide prospect.
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Revaz, Tristan, Mou Lin, and Fernando Porté-Agel. "Numerical Framework for Aerodynamic Characterization of Wind Turbine Airfoils: Application to Miniature Wind Turbine WiRE-01." Energies 13, no. 21 (October 27, 2020): 5612. http://dx.doi.org/10.3390/en13215612.
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A numerical framework for the aerodynamic characterization of wind turbine airfoils is developed and applied to the miniature wind turbine WiRE-01. The framework is based on a coupling between wall-resolved large eddy simulation (LES) and application of the blade element momentum theory (BEM). It provides not only results for the airfoil aerodynamics but also for the wind turbine, and allows to cover a large range of turbine operating conditions with a minimized computational cost. In order to provide the accuracy and the flexibility needed, the unstructured finite volume method (FVM) and the wall-adapting local eddy viscosity (WALE) model are used within the OpenFOAM toolbox. With the purpose of representing the turbulence experienced by the blade sections of the turbine, a practical turbulent inflow is proposed and the effect of the inflow turbulence on the airfoil aerodynamic performance is studied. It is found that the consideration of the inflow turbulence has a strong effect on the airfoil aerodynamic performance. Through the application of the framework to WiRE-01 miniature wind turbine, a comprehensive characterization of the airfoil used in this turbine is provided, simplifying future studies. In the same time, the numerical results for the turbine are validated with experimental results and good consistency is found. Overall, the airfoil and turbine designs are found to be well optimized, even if the effective angle of attack of the blades should be reduced close to the hub.
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Grasso, Francesco, Domenico Coiro, Nadia Bizzarrini, and Giuseppe Calise. "Design of advanced airfoil for stall-regulated wind turbines." Wind Energy Science 2, no. 2 (July 27, 2017): 403–13. http://dx.doi.org/10.5194/wes-2-403-2017.
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Abstract. Nowadays, all the modern megawatt-class wind turbines make use of pitch control to optimise the rotor performance and control the turbine. However, for kilowatt-range machines, stall-regulated solutions are still attractive and largely used for their simplicity and robustness. In the design phase, the aerodynamics plays a crucial role, especially concerning the selection/design of the necessary airfoils. This is because the airfoil performance is supposed to guarantee high wind turbine performance but also the necessary machine control capabilities. In the present work, the design of a new airfoil dedicated to stall machines is discussed. The design strategy makes use of a numerical optimisation scheme, where a gradient-based algorithm is coupled with the RFOIL code and an original Bezier-curves-based parameterisation to describe the airfoil shape. The performances of the new airfoil are compared in free- and fixed-transition conditions. In addition, the performance of the rotor is analysed, comparing the impact of the new geometry with alternative candidates. The results show that the new airfoil offers better performance and control than existing candidates do.
10
Chen, Qing Yuan, Feng Lin Guo, and Jin Quan Xu. "Applications of a Coupled Methodology to the Wind Turbine Airfoils." Advanced Materials Research 516-517 (May 2012): 572–76. http://dx.doi.org/10.4028/www.scientific.net/amr.516-517.572.
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In this study, a coupled methodology is proposed for the aerodynamic behavior of wind turbine airfoils. The idea is to combine a Navier-Stokes solver with a free vortex model. The zone for the calculation of CFD is confined to the surrounding of the airfoil, whilst the free vortex model accounts for the far field of the airfoil. The flow around the airfoil is assumed to be two-dimensional (2D) incompressible fully turbulent flow, which is modeled by two equation turbulence models. The computed aerodynamic coefficients are presented for two wind turbine airfoils and compared with wind tunnel data.
11
Timmer, W. A., and R. P. J. O. M. van Rooij. "Summary of the Delft University Wind Turbine Dedicated Airfoils." Journal of Solar Energy Engineering 125, no. 4 (November 1, 2003): 488–96. http://dx.doi.org/10.1115/1.1626129.
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This paper gives an overview of the design and wind tunnel test results of the wind turbine dedicated airfoils developed by Delft University of Technology (DUT). The DU-airfoils range in maximum relative thickness from 15% to 40% chord. The first designs were made with the XFOIL code. The computer program RFOIL, which is a modified version of XFOIL featuring an improved prediction around the maximum lift coefficient and the capability of predicting the effect of rotation on airfoil characteristics, has been used to design the airfoils since 1995. The measured effect of Gurney flaps, trailing edge wedges, vortex generators (vg) and trip wires on the airfoil characteristics of various DU-airfoils is presented. Furthermore, a relation between the thickness of the airfoil leading edge and the angle-of-attack for leading edge separation is given.
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Baker, J. P., E. A. Mayda, and C. P. van Dam. "Experimental Analysis of Thick Blunt Trailing-Edge Wind Turbine Airfoils." Journal of Solar Energy Engineering 128, no. 4 (July 19, 2006): 422–31. http://dx.doi.org/10.1115/1.2346701.
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An experimental investigation of blunt trailing-edge or flatback airfoils was conducted in the University of California, Davis aeronautical wind tunnel. The blunt trailing-edge airfoil is created by symmetrically adding thickness to both sides of the camber line of the FB-3500 airfoil, while maintaining the maximum thickness-to-chord ratio of 35%. Three airfoils of various trailing-edge thicknesses (0.5%, 8.75%, and 17.5% chord) are discussed in this paper. In the present study, each airfoil was tested under free and fixed boundary layer transition flow conditions at Reynolds numbers of 333,000 and 666,000. The fixed transition conditions were used to simulate surface soiling effects by placing artificial tripping devices at 2% chord on the suction surface and 5% chord on the pressure surface of each airfoil. The results of this investigation show that lift increases and the well-documented thick airfoil sensitivity to leading-edge transition reduces with increasing trailing-edge thickness. The flatback airfoils yield increased drag coefficients over the sharp trailing-edge airfoil due to an increase in base drag. The experimental results are compared against numerical predictions obtained with two different computational aerodynamics methods. Computations at bounded and unbounded conditions are used to quantify the wind tunnel wall corrections for the wind tunnel tests.
13
Xie, Huan, and Wei Zeng. "The Design Method of Airfoils for Variable-Pitch Wind Turbines Based on Knowledge Engineering." Advanced Materials Research 1030-1032 (September 2014): 1342–47. http://dx.doi.org/10.4028/www.scientific.net/amr.1030-1032.1342.
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In order to make good use of the previous design knowledge, the knowledge-based engineering ideas were introduced to the design of airfoils for variable-pitch wind turbines, a new design method for airfoil of wind turbine was formed. Firstly, the structure-behavior-function (SBF) model of airfoils design was derived. Secondly, the neural rules for airfoils design of variable-pitch wind turbines were deduced. Thirdly, the design method of airfoils structure for wind turbines based on case-based-reasoning (CBR) was establishment. And the dimensionless model based on case representation was set up, and the algorithm of geometric parameters design for airfoils based on CBR was proposed at last.
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Wang, Quan, Pan Huang, Di Gan, and Jun Wang. "Integrated Design of Aerodynamic Performance and Structural Characteristics for Medium Thickness Wind Turbine Airfoil." Applied Sciences 9, no. 23 (December 2, 2019): 5243. http://dx.doi.org/10.3390/app9235243.
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The currently geometric and aerodynamic characteristics for wind turbine airfoils with the medium thickness are studied to pursue maximum aerodynamic performance, while the interaction between blade stiffness and aerodynamic performance is neglected. Combining the airfoil functional integration theory and the mathematical model of the blade cross-section stiffness matrix, an integrated design method of aerodynamic performance and structural stiffness characteristics for the medium thickness airfoils is presented. The aerodynamic and structural comparison of the optimized WQ-A300 airfoil, WQ-B300 airfoil, and the classic DU97-W-300 airfoil were analyzed. The results show that the aerodynamic performance of the WQ-A300 and WQ-B300 airfoils are better than that of the DU97-W-300 airfoil. Though the aerodynamic performance of the WQ-B300 airfoil is slightly reduced compared to the WQ-A300 airfoil, its blade cross-sectional stiffness properties are improved as the flapwise and edgewise stiffness are increased by 6.2% and 8.4%, respectively. This study verifies the feasibility for the novel design method. Moreover, it also provides a good design idea for the wind turbine airfoils and blade structural properties with medium or large thickness.
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Yuan, Shang Ke, and Zi Qin Zhao. "Research on Wind Turbine Airfoils Aerodynamic Performance of Trailing Edge Modification." Applied Mechanics and Materials 741 (March 2015): 554–57. http://dx.doi.org/10.4028/www.scientific.net/amm.741.554.
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The airfoil commonly employed in wind turbines is modified by attaching a Gurney flap with length of 2% chord at its trailing edge and its remodeled form as well,but it showed special aerodynamic characteristics.The software FLUENT are respectively used to carry out numerical computation of aerodynamic performances of above-mentioned three airfoils, so that their aerodynamic characteristics, surface pressure distribution, and streamline around them are obtained for different angles of attack. It is shown by the computation result that the modified airfoils will result in such a strong downwash effect and the pressure distribution on airfoil surface is remarkably altered, the lift coefficient, and meantime the airfoil stalling is greatly postponed,but the airfoil of Gurney flap shown the characteristics of opposite.
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Solís-Gallego, Irene, Katia María Argüelles Díaz, Jesús Manuel Fernández Oro, and Sandra Velarde-Suárez. "Wall-Resolved LES Modeling of a Wind Turbine Airfoil at Different Angles of Attack." Journal of Marine Science and Engineering 8, no. 3 (March 19, 2020): 212. http://dx.doi.org/10.3390/jmse8030212.
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Noise has arisen as one of the main restrictions for the deployment of wind turbines in urban environments or in sensitive ecosystems like oceans for offshore and coastal applications. An LES model, adequately planned and resolved, is useful to describe the noise generation mechanisms in wind turbine airfoils. In this work, a wall-resolved LES model of the turbulent flow around a typical wind turbine airfoil is presented and described in detail. The numerical results obtained have been validated with hot wire measurements in a wind tunnel. The description of the boundary layer over the airfoil provides an insight into the main noise generation mechanism, which is known to be the scattering of the vortical disturbances in the boundary layer into acoustic waves at the airfoil trailing edge. In the present case, 2D wave instabilities are observed in both suction and pressure sides, but these perturbations are diffused into a turbulent boundary layer prior to the airfoil trailing edge, so tonal noise components are not expected in the far-field noise propagation. The results obtained can be used as input data for the prediction of noise propagation to the far-field using a hybrid aeroacoustic model.
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Mayda, E. A., and C. P. van Dam. "Bubble-Induced Unsteadiness on A Wind Turbine Airfoil." Journal of Solar Energy Engineering 124, no. 4 (November 1, 2002): 335–44. http://dx.doi.org/10.1115/1.1510525.
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The effect of laminar separation bubbles on the surface pressure distribution and aerodynamic force characteristics of a horizontal axis wind turbine airfoil is studied numerically. The NREL S809 airfoil for stall-controlled horizontal-axis wind turbines is analyzed at a chord Reynolds number of 1.0×106. For all flow conditions involving laminar separation in the present study, bubble-induced vortex shedding is observed. This flow phenomenon causes significant oscillations in the airfoil surface pressures and, hence, in the airfoil-generated aerodynamic forces. The computed time-averaged pressures compare favorably with wind-tunnel measurements.
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Tang, Xin Zi, Xu Zhang, Rui Tao Peng, and Xiong Wei Liu. "Wind Tunnel Experimental Study of Wind Turbine Airfoil Aerodynamic Characteristics." Applied Mechanics and Materials 260-261 (December 2012): 125–29. http://dx.doi.org/10.4028/www.scientific.net/amm.260-261.125.
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High lift and low drag are desirable for wind turbine blade airfoils. The performance of a high lift airfoil at high Reynolds number (Re) for large wind turbine blades is different from that at low Re number for small wind turbine blades. This paper investigates the performance of a high lift airfoil DU93-W-210 at high Re number in low Re number flows through wind tunnel testing. A series of low speed wind tunnel tests were conducted in a subsonic low turbulence closed return wind tunnel at the Re number from 2×105to 5×105. The results show that the maximum lift, minimum drag and stall angle differ at different Re numbers. Prior to the onset of stall, the lift coefficient increases linearly and the slope of the lift coefficient curve is larger at a higher Re number, the drag coefficient goes up gradually as angle of attack increases for these low Re numbers, meanwhile the stall angle moves from 14° to 12° while the Re number changes from 2×105to 5×105.
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Seralathan, Sivamani, T. Micha Premkumar, S. Thangavel, and G. P. Pradeep. "Numerical Studies on the Effect of Cambered Airfoil Blades on Self-Starting of Vertical Axis Wind Turbine Part 2: NACA 0018 and NACA 63415." Applied Mechanics and Materials 787 (August 2015): 245–49. http://dx.doi.org/10.4028/www.scientific.net/amm.787.245.
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NACA 0012 and NACA 4415 were discussed in Part 1 of the paper to study the capabilities of the airfoil blades by considering the effect of cambered airfoil blade on self-starting of vertical axis wind turbine. The numerical studies are carried out to identify self-starting capability of the airfoil using CFD analysis by studying the flow field over the vertical axis wind turbine blades. In this Part 2 paper, detailed numerical results of asymmetrical NACA 0018 and cambered airfoil NACA 63415 are presented. The lift force generated and the rotor torque induced varies with angle of attack. Based on the contours of static pressure and velocity distribution as well as based on the torque induced in the flow field over blade profiles, NACA 0018 is found to be better compared to cambered airfoil. Even though the lift force for cambered airfoils are higher, based on the rotor torque values, the wind turbine with asymmetrical airfoil blades NACA 0012 is better by 9.80% compared with NACA 4415 and 21.73% compared with NACA 63415. Self-starting issue can be addressed by proper selection of NACA blade profiles. By comparing the four airfoil blades in Part 1 and Part 2 of the papers, the asymmetrical NACA 0012 is found to be most suitable airfoil for self-starting the vertical axis wind turbine (VAWT).
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Xudong, Wang, Wang Licun, and Xia Hongjun. "An Integrated Method for Designing Airfoils Shapes." Mathematical Problems in Engineering 2015 (2015): 1–12. http://dx.doi.org/10.1155/2015/838674.
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A new method for designing wind turbine airfoils is presented in this paper. As a main component in the design method, airfoil profiles are expressed in a trigonometric series form using conformal transformations and series of polynomial equations. The characteristics of the coefficient parameters in the trigonometric expression for airfoils profiles are first studied. As a direct consequence, three generic airfoil profiles are obtained from the expression. To validate and show the generality of the trigonometric expression, the profiles of the NACA 64418 and S809 airfoils are expressed by the present expression. Using the trigonometric expression for airfoil profiles, a so-called integrated design method is developed for designing wind turbine airfoils. As airfoil shapes are expressed with analytical functions, the airfoil surface can be kept smooth in a high degree. In the optimization step, drag and lift force coefficients are calculated using the XFOIL code. Three new airfoils CQ-A15, CQ-A18, and CQ-A21 with a thickness of 15%, 18%, and 21%, respectively, are designed with the new integrated design method.
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Sareen, Agrim, Chinmay A. Sapre, and Michael S. Selig. "Effects of Leading-Edge Protection Tape on Wind Turbine Blade Performance." Wind Engineering 36, no. 5 (October 2012): 525–34. http://dx.doi.org/10.1260/0309-524x.36.5.525.
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This paper presents results of a study to investigate the impact of using wind protection tape (WPT) to protect the leading edge of wind turbine airfoils from erosion. The tests were conducted on the DU 96-W-180 wind turbine airfoil at three Reynolds numbers between 1 and 1.85 million and angles of attack spanning the low drag range of the airfoil. Tests were run by varying the chordwise extent of the wind protection tape on the upper and lower surface in order to determine the relative impact of each configuration on the aerodynamics of the airfoil. The objective was to assess the performance losses due to the wind protection tape and compare them with losses due to leading-edge erosion in order to determine the potential benefits of using such tape to protect wind turbine blades. Results showed that the application of wind protection tape caused a drag increase of 5–15% for the various configurations tested and was significantly less detrimental to airfoil performance than leading edge erosion that could otherwise occur.
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Mohd Hafiz, Mohd Noh, Abdul Hamid Ahmad Hussein, Rashid Helmi, Wisnoe Wirachman, and Syahmi Nasir Mohd. "Wind Tunnel Experiment for Low Wind Speed Wind Turbine Blade." Applied Mechanics and Materials 110-116 (October 2011): 1589–93. http://dx.doi.org/10.4028/www.scientific.net/amm.110-116.1589.
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Environment and green energy awareness are two main factors why this study has been carried out. This research is focused on aerodynamics study for airfoil structure modification based on NACA 0044 and NACA 0063 by using wind tunnel experiment. Aerodynamic characteristics such as lift coefficient, CL, drag coefficient, CD, lift to drag ratio and cell relative velocity has been investigated in this study. CFD simulation has been carried out at the early stage of the investigation (for NACA 0044 and NACA 0063), and a new airfoil profile had been created (0044-63) by modified the chord length and the location of maximum thickness of the airfoil by using the modified NACA Four-Digit Series. Wind tunnel experiment has been take place for three different wind speeds from 25m/s, 35m/s and 45m/s at various angles of attack from 0o to 40o with 5o incremental for the respective airfoil. The results show that the modified 0044-63 produced the better lift coefficient and this airfoil has been fabricated and tested in the wind tunnel experiment in order to validate the CFD result. This paper reports the result of aerodynamics characteristics for respective new airfoil and it shows that at angle of attack between 5 o to 15 o, this airfoil produced good lift to drag ratio value. Also, by modified the location of maximum thickness 30% to the trailing edge give the increment of lift to drag ratio produced approximately 15% and at the same time, give insignificant changes to the drag coefficient value.
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Gigue`re, P., and M. S. Selig. "Desirable Airfoil Characteristics for Large Variable-Speed Horizontal Axis Wind Turbines." Journal of Solar Energy Engineering 119, no. 3 (August 1, 1997): 253–60. http://dx.doi.org/10.1115/1.2888028.
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In an effort to define the desirable airfoil characteristics for large variable-speed wind turbines, a systematic study was performed using a series of airfoils designed to have similar aerodynamic properties, except for the amount of lift, which varied over a wide range. For several airfoil combinations, blade shapes were designed for a 750-kW wind turbine with a 48.8-m diameter rotor using the optimization code PROPGA together with PROPID, which is an inverse design method for horizontalaxis wind turbines. Roughness effects, including the consideration of dirty-blade performance in the blade-shape optimization process, were also considered and are discussed. The results and conclusions reveal practical design implications that should aid in the aerodynamic blade design of not only large but also other sizes of variable-speed wind turbines.
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Mitchell, Samuel, Iheanyichukwu Ogbonna, and Konstantin Volkov. "Aerodynamic Characteristics of a Single Airfoil for Vertical Axis Wind Turbine Blades and Performance Prediction of Wind Turbines." Fluids 6, no. 7 (July 13, 2021): 257. http://dx.doi.org/10.3390/fluids6070257.
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The design of wind turbines requires a deep insight into their complex aerodynamics, such as dynamic stall of a single airfoil and flow vortices. The calculation of the aerodynamic forces on the wind turbine blade at different angles of attack (AOAs) is a fundamental task in the design of the blades. The accurate and efficient calculation of aerodynamic forces (lift and drag) and the prediction of stall of an airfoil are challenging tasks. Computational fluid dynamics (CFD) is able to provide a better understanding of complex flows induced by the rotation of wind turbine blades. A numerical simulation is carried out to determine the aerodynamic characteristics of a single airfoil in a wide range of conditions. Reynolds-averaged Navier–Stokes (RANS) equations and large-eddy simulation (LES) results of flow over a single NACA0012 airfoil are presented in a wide range of AOAs from low lift through stall. Due to the symmetrical nature of airfoils, and also to reduce computational cost, the RANS simulation is performed in the 2D domain. However, the 3D domain is used for the LES calculations with periodical boundary conditions in the spanwise direction. The results obtained are verified and validated against experimental and computational data from previous works. The comparisons of LES and RANS results demonstrate that the RANS model considerably overpredicts the lift and drag of the airfoil at post-stall AOAs because the RANS model is not able to reproduce vorticity diffusion and the formation of the vortex. LES calculations offer good agreement with the experimental measurements.
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Pabón Rojas, Cristhian Leonardo, Carlos Andrés Trujillo Suarez, Juan Carlos Serrano Rico, and Elkin Gregorio Flórez Serrano. "Airfoil optimization for small horizontal axis wind turbine." Renewable Energy and Power Quality Journal 19 (September 2021): 505–10. http://dx.doi.org/10.24084/repqj19.330.
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In order to take advantage of the low wind speed found in the Colombian territory, a gradient-based optimization process (GBA) of 2 airfoils is carried out, using the Xfoil software to evaluate the interactions. The shapes chosen will be destined for the root and for the middle zone of a blade for a small horizontal axis wind turbine (sHAWT). The blade will be created from the calculation of the chord and pitch angle with the blade element momentum methodology (BEM) and the SHAWT will be tested by CFD software to check its performance. As a preliminary result, a root-bound airfoil has been obtained with a higher performance than the airfoil used as a bases.
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Feng, Fang, Shouyang Zhao, Chunming Qu, Yuedi Bai, Yuliang Zhang, and Yan Li. "Research on Aerodynamic Characteristics of Straight-Bladed Vertical Axis Wind Turbine with S Series Airfoils." International Journal of Rotating Machinery 2018 (2018): 1–13. http://dx.doi.org/10.1155/2018/8350243.
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Background. In order to investigate the effect of aerodynamic characteristics of S series airfoils on the straight-bladed vertical axis wind turbine (SB-VAWT), numerical simulations and wind tunnel experiments were carried out using a small SB-VAWT model with three kinds of blade airfoils, which are asymmetric airfoil S809, symmetric airfoil S1046, and NACA0018 used for performance comparison among S series. The aerodynamics characteristics researched in this study included static torque coefficient, out power coefficient, and rotational speed performance. The flow fields of these three kinds of blade under static and dynamic conditions were also simulated and analyzed to explain the mechanism effect of aerodynamic performance. According to the results, the SB-VAWT with airfoil S1046 has better dynamic aerodynamic characteristics than other two airfoils, while the SB-VAWT with airfoil S809 is better in terms of the static characteristics. As the most suitable airfoil for SB-VAWT, the S series airfoil is worth researching deeply.
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Le-Duc, Thang, and Quoc-Hung Nguyen. "Aerodynamic Optimal Design for Horizontal Axis Wind Turbine Airfoil Using Integrated Optimization Method." International Journal of Computational Methods 16, no. 08 (August 29, 2019): 1841004. http://dx.doi.org/10.1142/s0219876218410049.
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In this work, a new approach for aerodynamic optimization of horizontal axis wind turbine (HAWT) airfoil is presented. This technique combines commercial computational fluid dynamics (CFD) codes with differential evolution (DE), a reliable gradient-free global optimization method. During the optimization process, commercial CFD codes are used to evaluate aerodynamic characteristics of HAWT airfoil and an improved DE algorithm is utilized to find the optimal airfoil design. The objective of this research is to maximize the aerodynamic coefficients of HAWT airfoil at the design angle of attack (AOA) with specific ambient environment. The airfoil shape is modeled by control points which their coordinates are design variables. The reliability of CFD codes is validated by comparing the analytical results of a typical HAWT airfoil with its experimental data. Finally, the optimal design of wind turbine airfoil is evaluated about aerodynamic performance in comparison with existing airfoils and some discussions are performed.
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Chen, Ya Qiong, and Yue Fa Fang. "Research on Improved Method of Wind Turbine Airfoil S834 Based on Noise and Aerodynamic Performance." Applied Mechanics and Materials 744-746 (March 2015): 253–58. http://dx.doi.org/10.4028/www.scientific.net/amm.744-746.253.
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In this paper, aerodynamic performance and noise of the wind turbine airfoil are the optimization design goal and based on this, the optimization design method with multi-operating points and multi-objective of the airfoils is built. The Bezier curve is used in parametric modeling of the contour of the airfoil and the general equation for control points is deduced form the discrete points coordinates of the airfoil. The weigh distribution schemes for multi-objective and multi-operating points are integrated designed by treating the NREL S834 airfoil as the initial airfoils. The results show that the lift-to-drag ratio of the optimized airfoils has a improvement around the designed operating angle and the overall noise has a reduction compared with the initial airfoils, which means that the optimized airfoils get a better aerodynamic and acoustic performance.
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Chen, Jing Ru, Zhen Zhou Zhao, and Tao Li. "Characteristic Analysis of Three-Bladed Darrieus Wind Turbine Based on the Multiple Streamtube Model." Applied Mechanics and Materials 651-653 (September 2014): 663–67. http://dx.doi.org/10.4028/www.scientific.net/amm.651-653.663.
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The paper analyzes the effect of airfoil thickness, camber and blade pitch angle on the performance of the three-bladed Darrieus wind turbines. The research results show that the increase of airfoil thickness, camber and pitch angle of blade, can improve power coefficient when the wind turbine tip speed ratio between zero and four. The increase of thickness and camber of the airfoil leads to running tip speed ratio range of wind turbine get narrowed, and reduces the power coefficient when wind turbine runs in high tip speed ratio range. When the pitch angle of blade is 1˚, power coefficient reaches the maximum value. Negative pitch angle has a bad impact on power coefficient and even creates negative power coefficients.
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Wu, Pan, Chun Li, and Zhi Min Li. "Numerical Simulation of Influence with Surface Contamination on Aerodynamic Performance of Dedicated Wind Turbine Airfoil." Advanced Materials Research 724-725 (August 2013): 572–75. http://dx.doi.org/10.4028/www.scientific.net/amr.724-725.572.
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A Numerical simulation on the influence of airfoil surface contamination on the aerodynamic performance of wind turbines was performed. It chose the dedicated wind turbine airfoil as the research object. The k-ω Shear Stress Transmission (SST) turbulence model was selected for CFD calculation. The roughness height which arranged evenly on the airfoil was changed from 0.03mm to 2.0mm to obtain the sensitive roughness. The airfoil was divided into 18 sections for analyzing the effect on the lift & the drag coefficient, due to various locations of sensitive roughness. By comparing the result computed by XFOIL and CFD calculation, it can be known this airfoils sensitive locations in suction surface and pressure surface. The sensitive locations in suction surface were 53% and 92% from the chord line towards the leading edge, while 44% and 88% in pressure surface. The sensitive roughness in sensitive locations delayed the location of the transition point.
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Chen, Ya Qiong, Yue Fa Fang, and Sheng Guo. "Optimization and Design for Wind Turbine Airfoil at Multiple Working Conditions Based on Genetic Algorithm." Applied Mechanics and Materials 668-669 (October 2014): 230–35. http://dx.doi.org/10.4028/www.scientific.net/amm.668-669.230.
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S827 wind turbine airfoil was considered as original airfoil, which was created by NREL. Linear perturbation methods were used to get new shape parameters of wind turbine airfoil. Optimization of original airfoil was carried out based on genetic algorithm and XFOIL software, which was used to get aerodynamic performance. Results shows that the lift-drag radio of optimized airfoil was remarkable improved under multiple working conditions. Aerodynamic performance of optimized airfoil was much better comparing with the original airfoil. The optimal design method for wind turbine airfoil used in this paper can be used to optimization design of high lift-drag ratio wind turbine airfoil. Engineering practical value is considered by this method and it is feasible and efficient through example.
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Li, Xingxing, and Ke Yang. "Parametric exploration on the airfoil design space by numerical design of experiment methodology and multiple regression model." Proceedings of the Institution of Mechanical Engineers, Part A: Journal of Power and Energy 234, no. 1 (May 17, 2019): 3–18. http://dx.doi.org/10.1177/0957650919850426.
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Robust airfoil design is crucial to efficient, stable, and safe operation for modern wind turbines. However, even for deterministic wind turbine airfoil design, the problem is complex regarding to aerodynamic, acoustic, and structural requirements of wind turbine blades. Therefore, this study aims to assess the design variable impact, identify significant variables, and obtain the correlation with the airfoil responses, to reduce the cost of the airfoil robust optimization. In this paper, the optimal hypercube design method was applied to an airfoil designed by the National Advisory Committee for Aeronautics, NACA 63-421, which is commonly employed in the outboard modern wind turbine blade, to perform the numerical design of experiments. Then, a parametric exploration on the characteristics of airfoil design space by the multiple regression model and statistical analysis method were conducted. It was identified that in regular design space, the variations of aerodynamic and structural parameters are dominated by the airfoil camber and radius of leading edge. Meanwhile, the chord-wise position of the maximum thickness also has strong impacts on the airfoil performance. In further, the overall design spaces are explored to be highly nonlinear in aerodynamic and acoustic responses because of the nonlinear effects of the airfoil chord-wise position of the maximum camber and radius of leading edge. Strong but undesirable correlations were demonstrated between the maximum lift-to-drag ratio and the total sound pressure level. These findings could serve as a valuable guidance for wind turbine airfoil robust design to screen the stochastic design variables, simplify the design space, and reduce the cost.
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Jhon, Wabang A., Abanat D. J. Jufra, and Hattu Edwin. "ANALISA PERFORMA TURBIN ANGIN SUMBU HORISONTAL BERSUDU AIRFOIL MELALUI VARIASI JUMLAH SUDU." ROTOR 11, no. 2 (November 1, 2018): 18. http://dx.doi.org/10.19184/rotor.v11i2.9338.
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Indonesia is an area that has the potential for sufficient wind resources to be utilized for kinetic energy into other energy such as mechanical energy and electrical energy through its generators (generators). The way to utilize wind kinetic energy into other energy is through a device called a wind turbine. Wind turbines have been around since ancient times, and are called airfoil angled wind turbines. This airfoil wind turbine is designed only for areas with average wind speeds above 6m / s. While in Indonesia not all regions have the same wind speed. In certain seasons, the average wind speed is below 6 m / s. This has become a major problem in regions that have average wind speeds below 6 m / s. Seeing this condition, there is a need for scientific research to obtain wind turbines that can be used in areas with average wind speeds below 5m / s. For this reason, the research I want to do is get a wind turbine that can be used as a power plant in areas that have wind speeds below 6m / s. This research was conducted on the basis of scientific theory in fluid mechanics regarding the sweeping area of wind turbines and the performance of variations in the number of blades in the wind. In addition, the research in several scientific journals was used as the basis of this research
This research method is an experimental method, in the form of testing a wind turbine axis prototype horizontal and airfoil axis. The details of the research activity are the design and manufacture of laboratory scale horizontal airfoil axis turbines. Next, testing with a fan as a source of wind. The fan used has three variations of speed, all of which are used to determine the lowest average wind speed that can be applied. The results of the research are where wind turbines with the greatest torque and power and the Coefficient of Performance (CP) with the highest value will be used as a result to be applied to the community. Based on experimental data, it can be concluded that the greatest torque and power occur in turbines with 4 blades with details at speed 1, the largest torque and power are 0.201 Nm and 4.5 W; at speed 2, the biggest torque and power are 0.25 Nm and 7.21 W; at speed 3, the biggest torque and power are 0.28 Nm and 8.35 W
Keywords: wind turbine, airfoil, nozzle, diffuser
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Asli, Majid, Behnam Mashhadi Gholamali, and Abolghasem Mesgarpour Tousi. "Numerical Analysis of Wind Turbine Airfoil Aerodynamic Performance with Leading Edge Bump." Mathematical Problems in Engineering 2015 (2015): 1–8. http://dx.doi.org/10.1155/2015/493253.
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Aerodynamic performance improvement of wind turbine blade is the key process to improve wind turbine performance in electricity generated and energy conversion in renewable energy sources concept. The flow behavior on wind turbine blades profile and the relevant phenomena like stall can be improved by some modifications. In the present paper, Humpback Whales flippers leading edge protuberances model as a novel passive stall control method was investigated on S809 as a thick airfoil. The airfoil was numerically analyzed by CFD method in Reynolds number of 106and aerodynamic coefficients in static angle of attacks were validated with the experimental data reported by Somers in NREL. Therefore, computational results for modified airfoil with sinusoidal wavy leading edge were presented. The results revealed that, at low angles of attacks before the stall region, lift coefficient decreases slightly rather than baseline model. However, the modified airfoil has a smooth stall trend while baseline airfoil lift coefficient decreases sharply due to the separation which occurred on suction side. According to the flow physics over the airfoils, leading edge bumps act as vortex generator so vortices containing high level of momentum make the flow remain attached to the surface of the airfoil at high angle of attack and prevent it from having a deep stall.
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Simatupang, Reza, and Deddy Supriatna. "Designing a Tapperless Blade with an S-4320 Airfoil on a Micro-Scale Horizontal Axis Wind Turbine (Case Studies at PT Lentera Bumi Nusantara)." MOTIVECTION : Journal of Mechanical, Electrical and Industrial Engineering 3, no. 1 (January 31, 2021): 27–34. http://dx.doi.org/10.46574/motivection.v3i1.81.
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This article aims to design a taperless blade in a micro-scale wind turbine in medium wind speed, a case study at PT Lentera Bumi Nusantara. The methodology used in this research is quantitative research methods. Based on the test results in calculating the data using Microsoft Excel software and the blade airfoil design simulation using Qblade software, the use of the S-4320 airfoil in the application of the taperless blade design has research results that show that the airfoil design of the blade produces mechanical power at moderate wind speeds. It can be concluded that this blade design shows that the taperless blade with S-4320 airfoil can be applied to medium wind speeds in micro-scale horizontal axis wind turbines.
Artikel ini bertujuan untuk merancang bilah jenis taperless pada turbin angin skala mikro dalam kecepatan angin sedang, studi kasus pada PT Lentera Bumi Nusantara. Metodologi yang digunakan dalam penelitian ini adalah dengan metode penelitian kuantitatif. Berdasarkan hasil pengujian dalam perhitungan data menggunakan software Microsoft Excel dan simulasi perancangan desain airfoil bilah menggunakan software Qblade, penggunaan airfoil S-4320 dalam pengaplikasian desain bilah jenis taperless memiliki hasil penelitian yang menunjukan bahwa desain airfoil bilah tersebut menghasilkan tenaga mekanik pada kecepatan angin sedang. Dapat disimpulkan dalam desain bilah ini menunjukan bahwa bilah jenis taperless dengan airfoil S-4320 dapat diterapkan pada kecepatan angin sedang pada turbin angin sumbu horizontal skala mikro.
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Basualdo, Santiago. "Load Alleviation on Wind Turbine Blades Using Variable Airfoil Geometry." Wind Engineering 29, no. 2 (March 2005): 169–82. http://dx.doi.org/10.1260/0309524054797122.
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A two-dimensional theoretical study of the aeroelastic behaviour of an airfoil has been performed, whose geometry can be altered using a rear-mounted flap. This device is governed by a controller, whose objective is to reduce the airfoil displacements and, therefore, the stresses present in a real blade. The aerodynamic problem was solved numerically by a panel method using the potential theory, suitable for modelling attached flows. It is therefore mostly applicable for Pitch Regulated Variable Speed (PRVS) wind turbines, which mainly operate under this flow condition. The results show evident reductions in the airfoil displacements by using simple control strategies having the airfoil position and its first and second derivatives as input, especially at the system's eigenfrequency. The use of variable airfoil geometry is an effective means of reducing the vibration magnitudes of an airfoil that represents a section of a wind turbine blade, when subject to stochastic wind signals. The results of this investigation encourage further investigations with 3D aeroelastic models to predict the reduction in loads in real wind turbines.
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Wu, Zhenlong, and Yihua Cao. "Investigation of vertical axis wind turbine airfoil performance in rain." Proceedings of the Institution of Mechanical Engineers, Part A: Journal of Power and Energy 232, no. 2 (July 22, 2017): 181–94. http://dx.doi.org/10.1177/0957650917721776.
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Rainfall is a common meteorological condition that wind turbines may encounter and by which their performance may be affected. This paper comprehensively investigates the effects of rainfall on a NACA 0015 airfoil which is commonly used in vertical axis wind turbines. A CFD-based Eulerian–Lagrangian multiphase approach is proposed to study the static, rotating, and oscillating performances of the NACA 0015 airfoil in rainy conditions. It is found that for the different airfoil movements, the airfoil performance can seriously be deteriorated in the rain condition. Rain also causes premature boundary layer separations and more severe flow recirculations than in the dry condition. These findings seem to be the first open reports on rain effects on wind turbine performance and should be of some significance to practical design.
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Somers, D. M., and J. L. Tangler. "Wind Tunnel Test of the S814 Thick Root Airfoil." Journal of Solar Energy Engineering 118, no. 4 (November 1, 1996): 217–21. http://dx.doi.org/10.1115/1.2871781.
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The objective of this wind-tunnel test was to verify the predictions of the Eppler Airfoil Design and Analysis Code for a very thick airfoil having a high maximum lift coefficient designed to be largely insensitive to leading-edge roughness effects. The 24 percent thick S814 airfoil was designed with these characteristics to accommodate aerodynamic and structural considerations for the root region of a wind-turbine blade. In addition, the airfoil’s maximum lift-to-drag ratio was designed to occur at a high lift coefficient. To accomplish the objective, a two-dimensional wind tunnel test of the S814 thick root airfoil was conducted in January 1994 in the low-turbulence wind tunnel of the Delft University of Technology Low Speed Laboratory, The Netherlands. Data were obtained with transition free and transition fixed for Reynolds numbers of 0.7, 1.0, 1.5, 2.0, and 3.0 × 106. For the design Reynolds number of 1.5 × 106, the maximum lift coefficient with transition free is 1.32, which satisfies the design specification. However, this value is significantly lower than the predicted maximum lift coefficient of almost 1.6. With transition fixed at the leading edge, the maximum lift coefficient is 1.22. The small difference in maximum lift coefficient between the transition-free and transition-fixed conditions demonstrates the airfoil’s minimal sensitivity to roughness effects. The S814 root airfoil was designed to complement existing NREL low maximum-lift-coefficient tip-region airfoils for rotor blades 10 to 15 meters in length.
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Ye, Kun, Zheng Yin Ye, and Zhan Qu. "A New Design Concept for Wind Turbine Airfoil." Applied Mechanics and Materials 798 (October 2015): 8–14. http://dx.doi.org/10.4028/www.scientific.net/amm.798.8.
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Wind energy has been attracting more and more attentions due to its clean and renewable source. The aerodynamic characteristic of wind turbine airfoil directly affects the turbine efficiency. In order to improve the airfoil aerodynamic characteristic, a new concept airfoil configuration for wind turbine is presented. A cave on the upper surface near the trailing edge is designed to generate a trapped vortex in the cave. The trapped vortex is used to stabilize the separated flow when the airfoil at high angle of attack. Combining with the Gurney flap, the airfoil with the cave behaves very good aerodynamic characteristics at wide range of incidences, especially at high angles of attack. The method is used on the well-known FFA-W3-301 turbine airfoil. By using numerical simulation, it is shown that the new airfoil has a higher lift than the original airfoil at the same angle of attack, the stall angle of attack increases from 12 degree to 17 degree, and the maximum lift coefficient increases approximately 64 percents. In addition, the effects of the chord-wise location of starting point of the designed cave are discussed. Therefore, it is believed that the new-designed concept can be investigated and explored further for wind turbine.
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Li, Xinkai, Ke Yang, Hao Hu, Xiaodong Wang, and Shun Kang. "Effect of Tailing-Edge Thickness on Aerodynamic Noise for Wind Turbine Airfoil." Energies 12, no. 2 (January 16, 2019): 270. http://dx.doi.org/10.3390/en12020270.
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The influence of wind turbine airfoil trailing edge thickness on aerodynamics and aerodynamic noise characteristics was studied using the computational fluid dynamics (CFD)/ Ffowcs Williams–Hawkings (FW–H) method in the present work. First, the airfoil of a DU97-W-300-flatback airfoil was chosen as the research object, and numerical method validation was performed. Three kinds of turbulence calculation methods (unsteady Reynolds average Navier-Stokes (URANS), detached eddy simulation (DES), and large eddy simulation (LES)) were investigated in detail, and three sets of grid scales were used to study the impact of the airfoil on the aerodynamic noise. Secondly, the airfoil trailing edge thickness was changed, and the impact of trailing edge thickness on aerodynamics and aerodynamic noise was investigated. Results show that three kinds of turbulence calculation methods yield the same sound pressure frequency, and the magnitude of the sound pressure level (SPL) corresponding to the mean frequency is almost the same. The calculation of the SPL of the peak value and the experimental results can match well with each other, but the calculated core frequency is slightly lower than the experimental frequency. The results of URANS and DES are closer to each other with a changing trend of SPL, and the consequences of the DES calculation are closer to the experimental results. From the comparison of two airfoils, the blunt trailing edge (BTE) airfoil has higher lift and drag coefficients than the original airfoil. The basic frequency of lift coefficients of the BTE airfoil is less than that of the original airfoil. It is demonstrated that the trailing vortex shedding frequency of the original airfoil is higher than that of the BTE airfoil. At a small angle of attack (AOA), the distribution of SPL for the original airfoil exhibits low frequency characteristics, while, at high AOA, the wide frequency characteristic is presented. For the BTE airfoil, the distribution of SPL exhibits low frequency characteristics for the range of the AOA. The maximum AOA of SPL is 4° and the minimum AOA of SPL is 15°, while, for the original airfoil, the maximum AOA of SPL is 19°, and the minimum AOA is 8°. For most AOAs, the SPL of the BTE airfoil is larger than that of the original airfoil.
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Wang, Lin, Xinzi Tang, and Xiongwei Liu. "Blade Design Optimisation for Fixed-Pitch Fixed-Speed Wind Turbines." ISRN Renewable Energy 2012 (August 16, 2012): 1–8. http://dx.doi.org/10.5402/2012/682859.
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Fixed-pitch fixed-speed (FPFS) wind turbines have some distinct advantages over other topologies for small wind turbines, particularly for low wind speed sites. The blade design of FPFS wind turbines is fundamentally different to fixed-pitch variable-speed wind turbine blade design. Theoretically, it is difficult to obtain a global mathematical solution for the blade design optimisation. Through case studies of a given baseline wind turbine and its blade airfoil, this paper aims to demonstrate a practical method for optimum blade design of FPFS small wind turbines. The optimum blade design is based on the aerodynamic characteristics of the airfoil, that is, the lift and drag coefficients, and the annual mean wind speed. The design parameters for the blade optimisation include design wind speed, design tip speed ratio, and design attack angle. A series of design case studies using various design parameters are investigated for the wind turbine blade design. The design outcomes are analyzed and compared to each other against power performance of the rotor and annual energy production. The design outcomes from the limited design cases demonstrate clearly which blade design provides the best performance. This approach can be used for any practice of FPFS wind turbine blade design and refurbishment.
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Sun, Wen Lei, Guo Yu Hu, and Hong Jiang. "Blade Reverse Design of Large Wind Turbine." Key Engineering Materials 522 (August 2012): 503–6. http://dx.doi.org/10.4028/www.scientific.net/kem.522.503.
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Blade is one of key parts in wind turbine. Its shape design and airfoil selection directly affects the performance of wind turbine. This paper presented reverse redesign method of blade of large wind turbine and developed a blade airfoil automatically generating system. The redesign of blade is achieved through such processes as reverse measurement, reverse CAD modeling and blade reverse model analysis as well as determining the formula of blade section parameters. The blade airfoil automatically generating system has been applied.
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Yu, Jing Mei, Yan Hong Yu, and Pan Pan Liu. "Horizontal Axis Wind Turbine Numerical Simulation of Two Dimensional Angle of Attack." Advanced Materials Research 619 (December 2012): 111–14. http://dx.doi.org/10.4028/www.scientific.net/amr.619.111.
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wind power is the most effective form of wind energy utilization, modern large-scale wind turbine with horizontal axis wind mainly. Horizontal axis wind turbine aerodynamic performance calculation of the wind turbine aerodynamics research hot spot, is a wind turbine aerodynamic optimization design and calculation of critical load. Horizontal axis wind turbine airfoil aerodynamic performance of the wind turbine operation characteristics and life plays a decisive role". Using Fluent software on the horizontal axis wind turbine numerical simulation, analysis of the United States of America S809NREL airfoil aerodynamic characteristics of different angles of attack numerical simulation, analyzes the different angles of attack in the vicinity of the pressure, velocity distribution. By solving the two-dimensional unsteady, compressible N-S equations for the calculation of wind turbine airfoil S809used the characteristics of flow around. N-S equation in body-fitted coordinate system is given, with the Poisson equation method to generate the C grid.
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Zhu, Wei Jun, Nicolai Heilskov, Wen Zhong Shen, and Jens Nørkær Sørensen. "Modeling of Aerodynamically Generated Noise From Wind Turbines." Journal of Solar Energy Engineering 127, no. 4 (June 9, 2005): 517–28. http://dx.doi.org/10.1115/1.2035700.
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A semiempirical acoustic generation model based on the work of Brooks, Pope, and Marcolini [NASA Reference Publication 1218 (1989)] has been developed to predict aerodynamic noise from wind turbines. The model consists of dividing the blades of the wind turbine into two-dimensional airfoil sections and predicting the total noise emission as the sum of the contribution from each blade element. Input is the local relative velocities and boundary layer parameters. These quantities are obtained by combining the model with a Blade Element Momentum (BEM) technique to predict local inflow characteristics to the blades. Boundary layer characteristics are determined from two-dimensional computations of airfoils. The model is applied to the Bonus 300 kW wind turbine at a wind speed of 8 m/s. Comparisons of total noise spectra show good agreement with experimental data.
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Mikhailov, Yu S., and Yu G. Stepanov. "SIMULATION OF 2D FLOW AROUND OF AIRFOILS AT LOW-SPEED WIND TUNNEL WITH OPEN JET TEST-SECTION." Civil Aviation High TECHNOLOGIES 22, no. 1 (February 27, 2019): 51–62. http://dx.doi.org/10.26467/2079-0619-2019-22-1-51-62.
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At present, there is a great interest in the development of new airfoils for wind turbines and high-lift wings of unmanned aerial vehicles (UAV). The requirements for such airfoils differ from conventional aircraft airfoils, because of structural reasons and extreme operating conditions. So, wind turbine airfoils operate frequently under fully separated flow when stall is used for power regulation at high wind speeds. At the same time design of airfoils for wings UAV poses the problem of availability of high-lift at low Reynolds number. Modern airfoils are to a large extent developed from numerical methods. However, the complex flow conditions such as separation at high angles of attack, laminar separation bubbles and the transition from laminar to turbulent flow are difficult to predict accurately. Hence, testing of airfoils at a two-dimensional condition is an important phase in airfoil design. The development and validation of a 2D testing facility for investigation of single and multi-element airfoils in the wind tunnel Т-102 with open test section are considered in this article. T-102 is a continuous-operation, closed-layout wind tunnel with two reverse channels. The test section has an elliptical cross-section of 4 ×2,33 m and a length of 4 m. Two big flat panels of the L × H=3 ×3,9 m size installed upright on balance frame aligned with the free stream are used for simulating two-dimensional flow in the tunnel test section. The airfoil section in the layout of a rectangular wing is mounted horizontally between flat panels with minimum gaps to ensure 2D flow conditions. The aerodynamic forces and pitch moment acting on the model were measured by wind tunnel balance. To determine boundary corrections for a new test section of wind tunnel, the experimental investigation of three geometrically similar models has been executed. The use of boundary corrections has provided good correlation of the test data of airfoil NACA 6712 with the results obtained from the wind tunnel except for lift and drag coefficient values at high angles of attack.
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Zhao, Wan Li, and Xiao Lei Zheng. "Numerical Simulation on the Flow Control by Mounting Indented Gurney Flaps for a Wind Turbine." Advanced Materials Research 512-515 (May 2012): 623–27. http://dx.doi.org/10.4028/www.scientific.net/amr.512-515.623.
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Numerical investigation of large thick and low Reynolds airfoil of wind turbines by mounting indented Gurney flaps was carried out. The influenced rules of the position of Gurney flaps on the aerodynamic performance of airfoil under same height of flaps were achieved, and the optimal position of Gurney flap was presented. At last, the mechanism of wind turbine performance controlled by Gurney flap was discussed. The results can provide the theoretical guidance and technical support to wind turbines control in practical engineering.
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Hansen, T. H. "Airfoil optimization for wind turbine application." Wind Energy 21, no. 7 (April 11, 2018): 502–14. http://dx.doi.org/10.1002/we.2174.
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Yuan, Shang Ke, and Ren Nian Li. "Analysis Influence of Trailing Edge Modification on Aerodynamic Performance of Airfoils for Wind Turbine." Applied Mechanics and Materials 220-223 (November 2012): 900–904. http://dx.doi.org/10.4028/www.scientific.net/amm.220-223.900.
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The airfoil NACA 4412 commonly employed in wind turbines is modified by attaching a Gurney flap with length of 2% chord at its trailing edge and its remodeled form as well. The SIMPLE algorithm of finite volume method and software FLUENT are respectively used to carry out numerical computation of aerodynamic performances of above-mentioned three airfoils (including the un-modified one), so that their aerodynamic characteristics, pressure distribution on their surface, and streamline around them are obtained for different angles of attack. It is shown by the computation result that the modified airfoils will result in such a strong downwash effect that the pressure distribution on airfoil surface is remarkably altered, the lift coefficient and as well as the slope of lift-drag characteristic curve are increased, and meantime the airfoil stalling is greatly postponed.
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Xu, Jianhua, Zhonghua Han, Xiaochao Yan, and Wenping Song. "Design Optimization of a Multi-Megawatt Wind Turbine Blade with the NPU-MWA Airfoil Family." Energies 12, no. 17 (August 29, 2019): 3330. http://dx.doi.org/10.3390/en12173330.
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A new airfoil family, called NPU-MWA (Northwestern Polytechnical University Multi-megawatt Wind-turbine A-series) airfoils, was designed to improve both aerodynamic and structural performance, with the outboard airfoils being designed at high design lift coefficient and high Reynolds number, and the inboard airfoils being designed as flat-back airfoils. This article aims to design a multi-megawatt wind turbine blade in order to demonstrate the advantages of the NPU-MWA airfoils in improving wind energy capturing and structural weight reduction. The distributions of chord length and twist angle for a 5 MW wind turbine blade are optimized by a Kriging surrogate model-based optimizer, with aerodynamic performance being evaluated by blade element-momentum theory. The Reynolds-averaged Navier–Stokes equations solver was used to validate the improvement in aerodynamic performance. Results show that compared with an existing NREL (National Renewable Energy Laboratory) 5 MW blade, the maximum power coefficient of the optimized NPU 5 MW blade is larger, and the chord lengths at all span-wise sections are dramatically smaller, resulting in a significant structural weight reduction (9%). It is shown that the NPU-MWA airfoils feature excellent aerodynamic and structural performance for the design of multi-megawatt wind turbine blades.
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Wang, Chengyu, Filippo Campagnolo, and Carlo L. Bottasso. "Identification of airfoil polars from uncertain experimental measurements." Wind Energy Science 5, no. 4 (November 10, 2020): 1537–50. http://dx.doi.org/10.5194/wes-5-1537-2020.
Full textAbstract:
Abstract. A new method is described to identify the aerodynamic characteristics of blade airfoils directly from operational data of the turbine. Improving on a previously published approach, the present method is based on a new maximum likelihood formulation that includes errors in both the outputs and the inputs, generalizing the classical error-in-the-outputs-only formulation. Since many parameters are necessary to meaningfully represent the behavior of airfoil polars as functions of angle of attack and Reynolds number, the approach uses a singular value decomposition to solve for a reduced set of observable parameters. The new method is demonstrated by identifying high-quality polars for small-scale wind turbines used in wind tunnel experiments for wake and wind farm control research.