Drag Reduction for Wind Turbine Blades

The uneven distribution of electricity demand across Indonesia necessitates the development Renewable Energy Sources, particularly wind energy. This study evaluates performance efficiency horizontal-axis turbines equipped with two blade types: taper and taperless, both using NACA 0012 airfoil. Aerodynamic simulations were conducted QBlade software. Wind speed data from 2017 to 2022 sourced European Centre for Medium-Range Weather Forecasts (ECMWF), while consumption obtained Statistics Bureau Pesisir Barat Regency. A quantitative approach descriptive graphical analysis was employed compare metrics designs. results show that taperless achieves higher power coefficient (Cp) torque (Ct) values compared blade, although produces greater (T). energy conversion reached 347.6 kWh, representing an increase approximately 4.83% over 331.6 kWh generated by blade. Further indicates 19 taperless-blade are required meet daily 6,545 in These findings support recommendation adopt blades improved utilization region.

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Wind turbine with improved blade connecting tension members to extract more power from the wind. The tension members have a core surrounded by a textured layer. The core provides strength and the textured layer has a rougher surface. This texture reduces drag compared to a smooth core. The rougher texture also erodes less compared to a smooth surface in high wind conditions. The textured layer can be applied over the core in layers with different roughnesses to optimize the balance between drag reduction and erosion resistance.

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Airfoils for rotating turbines and propellers that improve efficiency and reduce drag compared to conventional airfoils. The airfoils have curved helical shapes with fins attached to the blades. The fins are positioned asymmetrically on the upper and lower halves of the blades. This configuration allows the fluid to flow through channels between the fins. It provides better connectedness and reduces drag compared to straight blades. The fins also divide the helical sections into equal parts. This allows uniform spacing between fins on each blade.

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Abstract. Wind farm flow control has demonstrated significant potential to increase wind power and energy production. Two commonly used methods are wake steering, which entails yaw misaligning individual turbines deflect wakes laterally, induction control, typically modifies the thrust coefficients of reduce deficits. These two approaches often studied utilized independently. This study investigates combination both these strategies, termed joint yaw-induction control. By synergistically controlling turbine angles levels, increased can be achieved compared either or in isolation. research leverages Unified Momentum Model capitalize on interplay between misalignment coefficient a rotor velocities generated by turbine. The is integrated with blade element modeling yield momentum model that predicts forces arbitrary input yaw, pitch, tip speed ratio, also initial needed for far-wake models. Forward-mode automatic differentiation into efficiently optimize strategies using gradient-based optimization. Using fast-running model, coupling Gaussian we demonstrate outperforms leading increases... Read More

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Structured body to reduce pressure drag on objects while also minimizing friction drag on fluids. The structured body has a curved face that comes into contact with the fluid and includes a frictional portion spreading in the direction of curvature, adjacent to a smooth portion. The frictional portion has features like protrusions, disturbance structures, or flow rectifiers. The smooth portion has lower height and width compared to the frictional portion. This configuration reduces separation of the fluid from the curved surface while still allowing flow attachment.

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A flow control framework based on linear stability analysis is proposed, focusing reducing the aerodynamic drag due to dynamic stall through a finite-window temporal actuation. The methodology applied periodically plunging SD7003 airfoil. Finite-time Lyapunov exponent (FTLE) fields reveal saddle point near airfoil leading edge, where shear layer forms and feeds vortex (DSV). local conducted at this identifies KelvinHelmholtz instability, most unstable eigenvalue frequencies remain constant when variation in effective angle of attack minimal. findings from FTLE are used inform position finite duty cycle periodic blowing suction actuation wall-resolved large-eddy simulation (LES). present reduces by 77.5% during motion while maintaining same performance as continuous throughout entire cycle. LES results demonstrate that disturbances stability-analysis-informed modify leading-edge dynamics, preventing formation coherent DSV significantly drag.

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Improving wind power plant efficiency is crucial due to the increasing demand for renewable energy. This study analyzes aerodynamic characteristics of a equipped with two combined blades that integrate fixed and rotating cylinders. The object model designed optimize airflow direction enhance lift. methodology involves numerical modeling using Ansys Fluent software package, as well experimental testing under laboratory conditions. main results show when air-flow velocity increases from 3 12 m/s, thrust force rises 0.5 N 3.85 N. Comparative analysis minimum maximum pressure on blade surfaces demonstrates strong correlation between rotational speed elevated differentials: pmax approximately 0.4 Pa 0.7 Pa, while pmin about 0.15 Pa. coefficient decreases 1.45 1.05 Reynolds number (Re) increases, indicating improved during transition turbulent flow. A comparative data reveals deviation no more than 5%, confirming models reliability soundness research methodology. conclusions indicate employing can by 810% compared traditional designs. improvement may foster development efficient stab... Read More

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Wet lay-up and vacuum-assisted resin transfer molding have been considered as the most popular cost-effective manufacturing processes of E-glass fiber reinforced epoxy-based laminated composite, especially in wind turbine blade industry. This study compares fatigue behavior GFRP composites manufactured via wet processes. Vacuum-assisted samples exhibited 85% longer life at a stress level 0.4 ultimate tensile strength compared to samples. The average was 50% higher, with improved resistance due enhanced fiber-matrix bonding. Scanning electron microscopy fracture analysis revealed fiber/matrix bonding fatigued samples, contributing performance. These findings provide critical insights for material selection optimization. results indicate that sustain 4.5 more load cycles lower levels, demonstrating superior performance blades.

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In this study, the aerodynamic performance of different wind turbine blades including FX 63-137, NACA 6415, 63-415 has been investigated. XFLR5 employed to analyze blade at Reynolds numbers ranging from 1.5x105 1x106 and low angles attack (00200). The lift (CL), drag(CD), pitch moment (CM) coefficients, lift/drag coefficient ratio (CL/CD) have evaluated. Numerical coefficients obtained using literature beeen compared it found that they compatible with each other. According numerical analyzes, highest coefficient-to-drag ratio, as called efficiency, was 109.14 FX63-137 Re number 1x106, lowest 2.63 blade. Also, maximum profile 104.28, while for NACA6415 102.11 1x106. analysis results show increases increase in angle up stall angle, then begins decrease all studied blades.

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In this paper, the aerodynamic performance of an improved hybrid vertical-axis wind turbine is investigated, and at high tipspeed ratios significantly enhanced by adding a spoiler end inner rotor. The design increases average torque coefficient 7.4% peak power 32.4%, which effectively solves problem loss due to negative rotor in conventional TSR; improves outer wake region optimizing airflow distribution, reducing counter-pressure differential, lowering drag same time attenuating turbulence intensity. study verifies validity through 2D CFD simulation, provides new idea for optimization turbines, especially suitable low speed complex terrain environments, great significance promotion renewable energy technology development.

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Current wind turbine optimization studies primarily employ either the Blade Element Method (BEM) or Computational Fluid Dynamics (CFD) to evaluate rotor aerodynamic performance. While BEM remains widely used due its simplicity and low computational cost, it depends heavily on empirical correction factors that can limit accuracy in complex flow conditions. Conversely, although CFD provides highly accurate results by solving Navier-Stokes equations, is computationally expensive often impractical for large-scale parametric studies. Vortex methodsparticularly prescribed wake methodoffer a promising compromise, balancing efficiency with acceptable levels of accuracy. In present study, we propose novel blade model derived through multi-objective blade's geometric parameters, specifically chord distribution twist angle. The performance optimized evaluated using an enhanced model. Aerodynamic noise estimated Brooks method, while production cost calculated Zudongs resulting design demonstrates 3% increase power output, 0.02 dB reduction emissions, marginal 1.2% cost. These finding... Read More

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ABSTRACT We develop a torquepitch control framework using deep reinforcement learning for wind turbines to optimize the generation of turbine energy while minimizing operational noise. employ double Qlearning, coupled blade element momentum solver, enable precise over parameters. In addition momentum, we use acoustic model Brooks Pope and Marcolini. Through training with simple winds, agent learns optimal policies that allow efficient complex turbulent winds. Our experiments demonstrate can find optimals at Pareto front when maximizing addition, adaptability changing conditions underscores its efficacy realworld applications. validate methodology SWT2.393 rated power 2.3 MW. compare classic controls show they are comparable noise emissions not taken into account. When including maximum limit 45 dBA in produced (100m downwind turbine), extracted yearly decreases by 22%. The is flexible allows easy tuning objectives constraints through reward definitions, resulting multiobjective optimization control. general, our findings highlight potential RLbased strategies imp... Read More

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An airfoil is the cross-sectional shape of a wing, blade, or sail, designed to generate aerodynamic forces as it moves through air. When interacting with airflow, an generates lift and drag forces. To standardize design, National Advisory Committee for Aeronautics (NACA) developed various families, extensive studies focused primarily on 4-digit series. However, limited attention has been given behaviour 5-digit This study assesses performance NACA 23012, airfoil, under varying Reynolds numbers angles attack establish its suitability high wind turbind. Computational Fluid Dynamics (CFD) simulations were conducted at (AoA) 8, 12, 16, 20, 24, 3.0106, 6.0106, 8.8106. The objective was identify conditions that yield optimal in terms lift-to-drag ratio (L/D), coefficient (CL), (CD). Results showed increase increasing AoA up critical range between 12 beyond which flow separation stall effects reduced efficiency. observed 8 angle number 8.8106, where relatively low resulted favourable ratio. A linear regression analysis revealed insignificant variation CFD results stand... Read More

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Riblets are a well-known passive drag reduction technique with the potential for as much $9\, \%$ in frictional force laboratory settings, and proven benefits large-scale aircraft. However, less information is available on applicability of these textures smaller air/waterborne vehicles where assumptions such periodicity and/or asymptotic nature boundary layer (BL) no longer apply shape bodies can give rise to moderate levels pressure drag. Here, we explore effect riblets both sides finite-size foil consisting streamlined leading edge flat body Reynolds number range $12\,200$ $24\,200$ . We use high-resolution two-dimensional, two-component particle image velocimetry, double illumination consecutive-overlapping imaging capture velocity field BL far field. find local profiles shear stress distribution, well components show possibility achieving record maximum cumulative up $6.5\, present intertwined relationship between distribution spanwise-averaged characteristics around body, how parameters work together or against each other enhancing diminishing drag-reducing ability entirety ... Read More

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Reducing skin friction of surfaces using passive phononic subsurfaces that alter fluid flow characteristics to delay boundary layer transition from laminar to turbulent. The subsurfaces are multi-input, multi-output phononic structures with interfaces exposed to flow pressure/velocity gradients. They contain phononic crystals or resonant metamaterials that passively change flow phase and amplitude in response to flow forces. By altering flow frequencies, the subsurfaces can reduce turbulence instability growth. The phononic subsurfaces can be integrated into surfaces like airfoils to passively delay boundary layer transition and reduce drag.

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This study investigates the optimum aerodynamic performance of small-scale Horizontal Axis Wind Turbines (HAWTs) utilizing a mixed-airfoil blade design. The QBlade software was employed for selection best performing airfoils based on lift-to-drag ratio and range operational performance. Additionally, Blade Element Momentum (BEM) theory deployed analysis blade's design Finally, in Computational Fluid Dynamics (CFD), SST k- turbulent model also applied better analysis. key findings demonstrated that optimal including SG6040 (root), NACA 4711 (middle), SG6043 (tip), were chosen their superior structural integrity. Furthermore, designed achieved power coefficients 0.454 (BEM), 0.432 (QBlade), 0.395 (CFD) at Tip Speed Ratio (TSR) 5.5, which are greater than conventional single-airfoil designs. It concluded configurations significantly enhance efficiency small scale wind turbines, future research torque control mechanism integration is essential to further optimize energy capture.

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Active lift modifying device for wind turbine rotor blades to reduce lift and increase drag during certain conditions. The device has fluid jets on the suction or pressure side of the blade that generate a curtain separating the airflow. Compressed fluid is supplied to the jets to create the curtain, reducing lift and increasing drag compared to normal blade operation. This can be useful in situations like shutdowns, extreme gusts, or turbulence when lower lift loads are desired. The device can be deactivated during normal operation to maintain high lift. The curtain size and location can be adjusted using separate compressed fluid sources or valves.

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This study investigates the applicability of modified Reynolds stress limiter to improve accuracy two-dimensional computational simulations Savonius wind turbine. The modification is applied shear transport k model by incorporating strength parameters a1 and Clim. numerical methods using User Define Function were first validated before being turbine under various flow tip speed ratios (TSRs) configurations. results show that increasing (or decreasing Clim) strengthens turbulent quantities, vortex zone inside blade, thin strain layer. These effects delay attachment separation along reduce positive pressure force on turbine, accelerate decay in wake, minimize deviation. Based analysis, a new set (a1 = 0.45 Clim 0.67) recommended, especially for high-fidelity at high TSRs, which standard turbulence models typically overestimate. finding essential accurately designing high-efficiency shows potential applications urban offshore environments.

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This project focuses on the optimization of a custom airfoil by systematically analyzing effects camber percentage (2% 6%), position (1 6), and angle attack (6) while maintaining fixed thickness 12%. The primary objective is to maximize lift- to-drag ratio (L/D) enhance aerodynamic efficiency stability. A parametric investigation was conducted using both unilabiate bivariate analyses evaluate influence individual combined parameters performance. To achieve this, XFOIL, high- fidelity analysis tool, integrated with MATLAB for automated batch processing, enabling efficient computation lift coefficient (C), drag (C), corresponding L/D ratios. study revealed that variations in its significantly affect characteristics, offering critical insights design optimized airfoils applicable aircraft wings, UAVs, wind turbine blades. In addition analysis, this explores advanced techniques, focus evolutionary algorithms such as Genetic Algorithm (GA). GA framework employed search configurations yield optimal ratios iteratively refining candidate solutions based selection, crossover, m... Read More

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Wind turbine blade design with offset flexible and stiff add-on elements to improve aerodynamics while facilitating handling. The blade has a mix of flexible and stiff add-on elements arranged offset in span and chord directions. The flexible elements are made of elastic materials like rubber to absorb impacts during handling. The stiff elements are made of stiffer materials. This allows protecting the flexible elements during blade handling without constraining their placement. The offset arrangement of flexible and stiff elements also improves blade aerodynamics by reducing drag and increasing lift compared to using all flexible or all stiff add-ons.

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Vertical axis wind turbine with a reactive shield system to increase efficiency by reducing drag on blades facing away from the wind. The shield changes shape based on wind direction to protect the opposite blade from wind pushback while allowing full exposure for the lead blade. This allows higher rotation speed and requires less wind to spin the turbine, increasing efficiency.

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Introduction Swept blades can achieve effective load reduction, thereby improving the operational performance of wind turbines. To investigate impact hundred-meter-level swept on characteristics turbines, this paper takes IEA-15 MW turbine as subject. Methods Based free-wake lifting line theory model and geometrically exact beam model, straight under rated conditions are compared. Results discussion The results show that undergo greater torsional deflection, reducing angle attack achieving reduction. influence different sweep parameters is also discussed. study finds reduction effects starting point index similar, while effect displacement most significant, it becomes more pronounced increases. Additionally, yaw conditions, increases, gradually increasing deflection decreasing amplitude flapwise speed fluctuation lead to a downward trend in both mean attack.

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This study explores a novel morphing blade design methodology to enhance the aerodynamic performance of NREL 1.5 MW wind turbine while addressing structural constraints. The proposed approach applies targeted leading and trailing edges sections, utilizing streamlined parameterization framework with four shape variables per airfoil: two deflection angles deformation starting points. process is modeled using an m-degree function optimized genetic algorithm maximize power generation minimizing displacement thrust forces. Turbine initially assessed Blade Element Momentum (BEM) theory validated through high-fidelity Computational Fluid Dynamics (CFD) simulations based on Reynolds-Averaged NavierStokes (RANS) equations k- turbulence model. Results demonstrate significant coefficient improvements up 23.8%, 10%, 7% at speeds 11.5 m/s, 8 4 respectively, compared baseline configuration. These findings highlight potential technologies improve energy efficiency in turbines adhering practical limitations.

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ABSTRACT Wind turbines operating in unsteady and complex environments often encounter asymmetric vortex flows on the suction side of blade, leading to airflow separation dynamic stall. These issues significantly impact aerodynamic performance energy efficiency wind turbines. Trailing edge flaps are an active flow control method mitigate stall; however, there is a lack research regarding regulatory relationship between airfoil parameters, trailing flap oscillation angles, parameters. To address this gap, numerical study employs multiblock overlapping grid technique customprogrammed simulate by coordinating motion main wing during pitching oscillations. Aerodynamic parameters airfoils were calculated investigate deflection direction, amplitude, other turbine blade section thrust, torque, characteristics under stall conditions. An optimized curve was produced. The results show that when occurred speed low, lift coefficient can be increased approximately 23% with amplitude amp1 = 40 same direction; moreover, tangential force torque value concurrently increased. Adjusting reduced ... Read More

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The blades of wind turbines constitute key components for converting energy into electrical energy, and modifications to blade airfoil geometry can effectively enhance aerodynamic performance turbine. trailing edge flap enables load control on the through adjustments its motion geometric parameters, thereby overcoming limitations inherent in conventional pitch systems. However, current research primarily emphasizes isolated parametric effects performance, with limited exploration interactions between multiple design variables. This study adopts a numerical simulation approach based FFA-W3-241 DTU 10 MW. Geometric deformations are achieved by manipulating influence is analyzed using computational fluid dynamics methods. Investigations conducted lengths deflection angles characteristics. results show existence an optimal length angle combination. Specifically, when 0.1c 10, lift-to-drag ratio demonstrates significant improvement under defined operational conditions. These findings offer practical guidance optimizing turbine designs.

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This paper investigate the flow separation behavior of a turbine blade using NACA 63-415 airfoil in three arrangements- without slot, with single double slot. Computational fluid dynamic simulation are used to study at 0 20 degree angle attack.to how begins and develops. The targets determination significant attack which initiates since it influences both efficiency performance blade. Important aerodynamics factors like pressure distribution, velocity contours impact turbulence assesses determine change patterns. Further research explores whether slot modification leading edge efficient controlling or postponing hence aerodynamic efficiently can be improved. Single existence is explored find their effectiveness enhancing lift drag ratio, lowering intensity ensuring smoother on surface.

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Rotary blade design for wind turbines and other fluid flow devices to improve rotation efficiency. The blade has a front curved surface that protrudes forward in rotation direction and a rear curved surface that is concave and has less depth. The rear surface connects to the front surface at an inner end. A recess is formed on the front surface. The recess has a stepped inner surface facing rearward and connects to the outer end. The recess allows tailwind to flow around and generate lift force. The stepped inner surface has a smaller slope angle than the outer surface. This design enables higher rotation speed compared to conventional blades using only drag force. The blades can be arranged in stages with an angle difference for better overall efficiency.

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Automated robotic system for creating customized leading-edge protectors (LEPs) on wind turbine blades without the need for prefabricated shells. The system uses a robotic arm guided by a computer to deposit liquid polymer directly onto the blade in layers. The arm has multiple degrees of freedom to maneuver and dispense the polymer onto the blade surface. This allows building up the LEP layer by layer, following the blade shape, to provide a seamless, tailored LEP. The polymer is cured on the blade. The robotic deposition avoids gaps, overlaps, and air pockets compared to applying preformed shells.

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Blade for fluid equipment like turbines with reduced drag and improved heat resistance. The blade has a riblet structure on the surface that promotes fluid flow and reduces drag. The riblet structure can be formed by irradiating the surface with an energy beam. The blade also has a heat-resistant coating to reduce heat transfer. The coating has a different groove pitch, depth, or spacing compared to the riblet structure grooves. This prevents disruption of fluid flow along the riblets. The blade can also have a coat layer over the riblet structure. The riblet structure can be formed on the base member before coating.

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A vertical axis wind turbine design with a reactive shield to improve efficiency by reducing drag on blades facing away from the wind. The shield changes orientation as the blades rotate, minimizing wind contact on the returning blades. This allows those blades to spin freely without drag, while the windward blade maximizes exposure. The shielded blades require less wind to turn, increasing rotation speed and overall efficiency.

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Double-set blade wind turbine design with two concentric cylinders of blades around the central hub. The inner cylinder has blades that rotate with the wind, while the outer cylinder has fixed blades. The blades on the inner rotating cylinder have a different curvature compared to the outer fixed cylinder. This asymmetric blade configuration improves power output by reducing wind interference between the blades as they rotate. The fixed outer blades prevent the wind from stalling the inner rotating blades, allowing them to continue generating power.

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Wind turbine blade design that improves power generation and lift by reducing vorticity downstream. The blade has an increasing chord towards the tip, changing twist angle, and/or thickness along the length. This creates counter-rotating vortices behind the blade for higher efficiency. The chord has a local minimum, max closer to the tip, and inflection points. The twist has min, max closer to tip. The blade shape reduces vorticity and increases lift compared to conventional designs.

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Horizontal axis wind turbine blade design that improves efficiency at high speeds. The blade has an airfoil section with a double-sided lift profile that allows it to maintain lift and generate power at supersonic speeds. The airfoil has a unique shape where the upper and lower edges intersect directly instead of forming a gap. This prevents separation and stall at high speeds. The blade also has a shock wave management system to reduce damage and noise at supersonic speeds. The shock wave angles are calculated to reduce windward side speeds without generating shocks. This enables the blade to operate efficiently at very high wind speeds.

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Wind turbine blade design with reduced aerodynamic resistance at the root section to improve overall blade efficiency. The blade root has recessed portions that are concave indents recessed into the pressure and suction surfaces. These recesses are hemispherical in shape and have limited diameter to avoid weakening structural integrity. By recessing the root section, it reduces drag and allows thinner blade roots without sacrificing strength. This improves lift-to-drag ratio and reduces loads on the tower and hub.

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A vertical-axis wind turbine system that uses a wind director to improve efficiency by reducing drag on the returning blade while increasing force on the advancing blade. The wind director has an inlet that captures wind and an outlet that narrows to increase wind speed. This directed wind is applied to the advancing blade. The wind director also has a secondary duct angled to provide additional forward force on the returning blade.

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Blade design for wind turbines with reduced starting wind speed and improved efficiency. The blade has a unique airfoil shape with ten curved surfaces that smoothly transition from pressure to suction sides. This wide, gradually tapering airfoil section near the root reduces starting wind speeds compared to conventional blades. The wide root also reduces blade mass and inertia. The blade tip is not a separate structure but an extension of the airfoil. This eliminates tip vortices and noise.

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Wind turbine blade with reduced drag and improved lift compared to conventional blades. The blade profile is created by using a specific airfoil shape at each cross-section. The airfoil shape follows a curve that starts at the ridge line of the blade and tapers towards the tip. This profile reduces drag and improves lift compared to traditional blades with constant airfoil sections.

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A family of wind turbine airfoils with blunt trailing edges that have wide operating Reynolds number ranges. The family includes three airfoils with blunt trailing edges that are compatible for use in wind turbine blades. The airfoils have dimensionless two-dimensional coordinate expressions for their profiles. The expressions are provided for the first, second, and third blunt trailing edge airfoils. By having a family of blunt trailing edge airfoils with wide operating Reynolds numbers, it allows wind turbine blades with longer lengths and higher velocities to have improved aerodynamic performance and structural compatibility.

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Rotor blade design for wind turbines that balances lift, drag, and structural strength. The blade has a middle section with a local minimum in lift coefficient. This allows higher thickness and depth in the structurally loaded middle section without excessive lift. The thicker middle section improves strength without excessive drag. The blade also has optimized thickness setback profile that reduces drag.

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Design method for improving aerodynamic performance of wind turbine blades with thick airfoils that stall easily. The method involves optimizing the suction side profile of the airfoil using a simulated annealing multi-objective evolutionary algorithm to find a profile that improves lift-to-drag ratio both before and after stall compared to the original airfoil. The algorithm calculates aerodynamic performance using fluid simulation software like Fluent. The optimized airfoil, named WT-E-300, was found to have better stall characteristics compared to the standard DU97-W-300 airfoil.

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Wind turbine blade design to improve aerodynamics and energy production. The design includes attaching flow-modifying devices like spoilers or Gurney flaps to the surface of the blade. The devices are attached with flexible housings filled with adhesive to bond them to the blade surface. This allows the devices to modify airflow and increase lift without compromising blade structural integrity.

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A cross-flow airfoil design for wind turbine blades that improves efficiency compared to conventional blades. The cross-flow airfoil has a middle section with a suction surface made of three circular arc segments connected by transitions. This shape allows smooth airflow transition between the blade pressure and suction sides when crosswinds hit the blade. This reduces drag and vortex formation compared to conventional airfoils with abrupt transitions. The cross-flow airfoil can be used in wind turbine blades to improve performance in crosswind conditions.

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Airfoil shape for wind turbine blades that improves lift, stall angle, and drag compared to conventional wind turbine airfoils. The airfoil has a unique cross-section with sections named S1-S5. The upper surface transitions smoothly from trailing edge to leading edge (S2) and then has excessive curvature (S3). The lower surface has a concave shape (S5) with larger camber than conventional airfoils (S809). This design ensures small angle of attack lift, inhibits separation at high angles, and improves lift and drag compared to conventional airfoils.

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Low Reynolds number blade airfoil for wind turbines in low wind speed areas. The airfoil is optimized for low Reynolds numbers, which is important for small wind turbines in areas with lower wind speeds. The airfoil has a unique shape with a cambered pressure surface and a slightly cambered suction surface. This provides a higher lift-to-drag ratio compared to traditional aviation airfoils in low Reynolds numbers. The cambered pressure surface reduces pressure drag, while the cambered suction surface reduces separation and vortices. The airfoil has a maximum relative bending of 6.34-8.69% at 39.5% chord length.

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Airfoil shape optimized for wind turbine blades operating at low Reynolds numbers. The airfoil has specific thickness and curvature locations to reduce separation and improve aerodynamic efficiency at low wind speeds. The maximum thickness is 11.1% of the chord length at 26% chord position, and the maximum curvature is 5.7% of the chord length at 53.1% chord position.

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A flexible trailing edge extender for wind turbine blades that improves aerodynamic performance without adding weight and cost. The extender is a flexible aeroshell piece that can be attached to the trailing edge of a wind turbine blade section. The extender piece has slits cut into it that allow it to bend and flex. This configuration allows the extender to withstand operational stresses and strains better than a rigid extender.

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A wind turbine that uses a variable geometry diffuser to control drag forces and maximize power production. The diffuser augmentation increases the wind pressure at the turbine outlet. The variable geometry allows adjusting the diffuser shape based on wind speed to reduce drag at high speeds and increase augmentation at low speeds. The diffuser has a fixed inner section and a rotatable outer section. The rotation angle of the outer section is controlled based on wind velocity to open the diffuser wall between 50% and 100%.

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Bionic leading edge wind power blade design to improve aerodynamics and reduce noise compared to traditional blades. The blade has a sinusoidally varying convex leading edge shape that is periodically distributed along the blade. This bionic leading edge geometry promotes boundary layer attachment, reduces separation, and improves performance over the entire blade span. The convex shape is optimized through testing and design to balance aerodynamics and noise reduction.

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Wind turbine blade with a high lift-drag ratio coefficient to improve wind energy utilization efficiency. The blade has a curved leading edge, pointed and curved trailing edge, and a fan-shaped root transition. The blade airfoil section is created by smoothly connecting 241 sets of spatial coordinates with varying torsion angles. This design provides a blade shape that has a high lift-drag ratio without stalling at high angles of attack.

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A vortex generator device for wind turbine blades that improves mounting strength and aerodynamics compared to existing vortex generators. The device has a base and two asymmetrically sized fins protruding from one side. The fins are arranged so that the distance between their primary ends is greater than the distance between their secondary ends. The fins also have asymmetric heights, with the primary fin end being shorter.

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