Experimental Testing of Periodic Roughness Elements on a Small Scale Wind Turbine Blade

2010 ◽  
Author(s):  
Jason R. Gregg ◽  
Kenneth W. Van Treuren
Keyword(s):  
Wind Tunnel ◽  
Wind Turbine ◽  
Turbine Blade ◽  
Experimental Testing ◽  
Turbine Blades ◽  
Wind Turbine Blade ◽  
Speed Ratio ◽  
Small Scale ◽  
Turbine Performance ◽  
Roughness Elements

When studied in large wind turbines, roughness on wind turbine blades has been shown to decrease wind turbine performance by up to 50%. However, during wind turbine testing in the Baylor University Subsonic Wind Tunnel, roughness effects that were an artifact of the blade manufacturing process led to a significant power increase over smooth blades at the design wind speed of 10 mph. These results have led to an investigation of the effects of roughness on wind turbine performance under a flow condition with local Reynolds numbers ranging from 14,200 to 58,800. It was found that under these flow conditions the roughness can improve measured power output by up to 126% when compared with a smooth blade. This paper examines the conditions where roughness can positively affect the operation of a wind turbine by testing a 500 mm diameter, horizontal axis, three blade, fixed pitch wind turbine system in a wind tunnel. The experiments have been carried out on a single direct-drive wind turbine model and a single blade design using the NREL designed S818 airfoil. The design point for the blades tested is 10 miles per hour, with a tip speed ratio of 7. Roughness can be an effective treatment when used at or near the stall speed of the wind turbine blade for lower Reynolds number conditions. The roughness elements tested were both perpendicular to and along the flow lines. These blades were then compared to a blade configuration without roughness elements.

Experimental investigation of wind loads on wind turbine blade under various turbulent flows

2021 ◽  
pp. 136943322110401
Author(s):  
Yi Li ◽  
Qian Song ◽  
Qiu-Sheng Li ◽  
Di-Ling Wang ◽  
Xiao-Peng Wu
Keyword(s):  
Wind Tunnel ◽  
Wind Turbine ◽  
Turbine Blade ◽  
Dynamic Properties ◽  
Turbine Blades ◽  
Wind Farms ◽  
Wind Turbine Blade ◽  
Wind Pressure ◽  
Wind Loads ◽  
Pressure Coefficients

For investigation of the effects of turbulence intensity (TI) on the wind loads on wind turbine blade, a 1:20 scaled model of a typical 3D wind turbine blade is designed and used for the pressure measurement test in a wind tunnel. Five uniform flows with different turbulence intensities are simulated in the wind tunnel test. The mean and root-mean-square (RMS) wind pressure coefficients, base moment coefficients, and their power spectral densities are presented and discussed in detail. Combined with the dynamic properties of the blade structure, wind-induced displacements at the tip of the blade are calculated by the random vibration theory. The results show that the increasing of TI amplifies the aerodynamic loads on the blade in terms of RMS wind pressure coefficients and RMS bending moment coefficients. Large wind-induced displacement of the wind turbine blade may be stimulated by high TI even under the feathering condition. This article aims to further the understanding of wind loads on wind turbine blades and provide useful information for the wind-resistant design of wind farms established in regions with high turbulence levels.

Testing Rotating Horizontal Axis Wind Turbine Blade Designs in a Laboratory Wind Tunnel

2010 ◽  
Author(s):  
Kenneth W. Van Treuren ◽  
Jason R. Gregg
Keyword(s):  
Surface Roughness ◽  
Wind Tunnel ◽  
Wind Turbine ◽  
Turbine Blade ◽  
Turbine Blades ◽  
Reynolds Numbers ◽  
Full Scale ◽  
Wind Turbine Blade ◽  
Wind Tunnel Testing ◽  
Wind Turbine Blades

The importance of renewable and alternative energy is rapidly gaining attention. A national goal of replacing 20% of the United States electricity generation with wind power by 2030 has been proposed but such an ambitious goal is dependent on many parameters. Improved aerodynamic performance of wind turbine blades is one parameter necessary to achieve this goal. Blade testing is traditionally done using 2D airfoils in a laboratory wind tunnel, developing the lift and drag coefficients, and then using this data to predict wind turbine blade performance. Dimensional analysis has been used successfully in design of rotating machinery such as pumps, developing a series of dimensionless pump parameters with which to scale a particular pump design to a larger or small size. These parameters lead to similarity or affinity laws which relate any two homologous states for two pumps that are geometrically and dynamically similar. Affinity laws could be applied to wind turbines however the conditions tested in the wind tunnel do not match what would be expected in a full scale wind machine. As with pumps, the laws would apply only if the model and full scale wind turbine would operate at identical Reynolds numbers and are exactly similar (i.e. relative surface roughness and tip conditions). Reynolds numbers in the model tests are smaller than those achieved by the actual wind turbines while the surface roughness of the model is generally larger. This leads to the need for empirical equations to predict performance. This paper examines current wind tunnel testing and the problems with scaling wind turbine blades. It also outlines a methodology to test 3-D model wind turbine blades in a wind tunnel. Blades are designed and manufactured according to existing criteria, mounted to a generator, and their performance is then tested in the wind tunnel. Challenges with wind tunnel testing as well as extrapolation of the wind tunnel data to actual applications will be addressed.

Machine Learning Aided Prediction of Rain Erosion Damage on Wind Turbine Blade Sections

2021 ◽  
Author(s):  
Alessio Castorrini ◽  
Paolo Venturini ◽  
Fabrizio Gerboni ◽  
Alessandro Corsini ◽  
Franco Rispoli
Keyword(s):  
Wind Turbine ◽  
Turbine Blade ◽  
Energy Production ◽  
Turbine Blades ◽  
Wind Farms ◽  
Wind Turbine Blade ◽  
Wind Turbine Blades ◽  
Coating Materials ◽  
Erosion Modelling ◽  
Rain Erosion

Abstract Rain erosion of wind turbine blades represents an interesting topic of study due to its non-negligible impact on annual energy production of the wind farms installed in rainy sites. A considerable amount of recent research works has been oriented to this subject, proposing rain erosion modelling, performance losses prediction, structural issues studies, etc. This work aims to present a new method to predict the damage on a wind turbine blade. The method is applied here to study the effect of different rain conditions and blade coating materials, on the damage produced by the rain over a representative section of a reference 5MW turbine blade operating in normal turbulence wind conditions.

An Investigation of the Aerodynamic Response of a Wind Turbine Blade to Tower Shadow

2004 ◽  
Vol 126 (4) ◽  
pp. 1034-1040 ◽  
Author(s):  
Xabier Munduate ◽  
Frank N. Coton ◽  
Roderick A.McD. Galbraith
Keyword(s):  
Wind Turbine ◽  
Turbine Blade ◽  
Careful Consideration ◽  
Wind Turbine Blade ◽  
Small Scale ◽  
Force Coefficient ◽  
Velocity Deficit ◽  
Pressure Transducers ◽  
Aerodynamic Model ◽  
Tower Shadow

This paper presents results from a wind tunnel based examination of the response of a wind turbine blade to tower shadow in head-on flow. In the experiment, one of the blades of a small-scale, two-bladed, downwind turbine was instrumented with miniature pressure transducers to allow recording of the blade surface pressure response through tower shadow. The surface pressures were then integrated to provide the normal force coefficient responses presented in this paper. It is shown that it is possible to reproduce the measured responses using an indicially formulated unsteady aerodynamic model applied to a cosine wake velocity deficit. It is also shown that agreement between the model and the measured data can be improved by careful consideration of the velocity deficit geometry.

scholarly journals Design and Development of a New Small-Scale Wind Turbine Blade

2015 ◽  
Author(s):  
Ulan Dakeev ◽  
Quamrul Mazumder ◽  
Faruk Yildiz ◽  
Kenan Baltaci
Keyword(s):  
Wind Turbine ◽  
Turbine Blade ◽  
Wind Turbine Blade ◽  
Small Scale ◽  
Design And Development

Design and Analysis of Wind Turbine Blades: Winglet, Tubercle, and Slotted

2013 ◽  
Author(s):  
Alka Gupta ◽  
Abdulrahman Alsultan ◽  
R. S. Amano ◽  
Sourabh Kumar ◽  
Andrew D. Welsh
Keyword(s):  
Power Generation ◽  
Wind Turbine ◽  
Turbine Blade ◽  
Alternative Energy ◽  
Turbine Blades ◽  
Three Dimensional ◽  
Wind Turbine Blade ◽  
Wind Turbine Blades ◽  
Wind Speeds ◽  
Governing Factor

Energy is the heart of today’s civilization and the demand seems to be increasing with our growing population. Alternative energy solutions are the future of energy, whereas the fossil-based fuels are finite and deemed to become extinct. The design of the wind turbine blade is the main governing factor that affects power generation from the wind turbine. Different airfoils, angle of twist and blade dimensions are the parameters that control the efficiency of the wind turbine. This study is aimed at investigating the aerodynamic performance of the wind turbine blade. In the present paper, we discuss innovative blade designs using the NACA 4412 airfoil, comparing them with a straight swept blade. The wake region was measured in the lab with a straight blade. All the results with different designs of blades were compared for their performance. A complete three-dimensional computational analysis was carried out to compare the power generation in each case for different wind speeds. It was found from the numerical analysis that the slotted blade yielded the most power generation among the other blade designs.

Research on Wind Turbine Blade Loads and Dynamics Factors

2014 ◽  
Vol 1014 ◽  
pp. 124-127
Author(s):  
Zhi Qiang Xu ◽  
Jian Huang
Keyword(s):  
Wind Turbine ◽  
Turbine Blade ◽  
Wind Turbines ◽  
Mechanical Energy ◽  
Turbine Blades ◽  
Electrical Energy ◽  
Wind Turbine Blade ◽  
Strength Analysis ◽  
Wind Turbine Blades ◽  
Turbine Wheel

Wind turbines consists of three key parts, namely, wind wheels (including blades, hub, etc.), cabin (including gearboxes, motors, controls, etc.) and the tower and Foundation. Wind turbine wheel is the most important part ,which is made up of blades and hubs. Blade has a good aerodynamic shape, which will produce aerodynamic in the airflow rotation, converting wind energy into mechanical energy, and then, driving the generator into electrical energy by gearbox pace. Wind turbine operates in the natural environment, their load wind turbine blades are more complex. Therefore load calculations and strength analysis for wind turbine design is very important. Wind turbine blades are core components of wind turbines, so understanding of their loads and dynamics by which the load on the wind turbine blade design is of great significance.

scholarly journals Preparation and Anti-Icing of Hydrophobic Polypyrrole Coatings on Wind Turbine Blade

2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Bin Qu ◽  
Zhou Sun ◽  
Fang Feng ◽  
Yan Li ◽  
Guoqiang Tong ◽  
...  
Keyword(s):  
Contact Angle ◽  
Wind Turbine ◽  
Turbine Blade ◽  
Water Contact Angle ◽  
Turbine Blades ◽  
Wind Turbine Blade ◽  
Wind Turbine Blades ◽  
Water Contact

This paper describes the method of preparing strong hydrophobic polypyrrole (PPy) on wind turbine blades. The water contact angle of strong hydrophobic PPy coatings was 127.2°. The strong hydrophobic PPy coatings exhibited excellent anti-icing properties. The maximum icing weight of strong hydrophobic PPy coating blade was almost 0.10 g while the maximum icing weight of no coating blade was found to be 26.13 g. The maximum icing thickness of a strong hydrophobic PPy coating blade was only 1.08 mm. The current research will provide a better technique to create anti-icing coatings on wind turbine blades and other outdoor equipment.

scholarly journals Design Optimization of a Multi-Megawatt Wind Turbine Blade with the NPU-MWA Airfoil Family

Energies ◽  
2019 ◽  
Vol 12 (17) ◽  
pp. 3330 ◽  
Author(s):  
Jianhua Xu ◽  
Zhonghua Han ◽  
Xiaochao Yan ◽  
Wenping Song
Keyword(s):  
Wind Turbine ◽  
Turbine Blade ◽  
Weight Reduction ◽  
Stokes Equations ◽  
Lift Coefficient ◽  
Turbine Blades ◽  
Aerodynamic Performance ◽  
Wind Turbine Blade ◽  
Structural Performance ◽  
Power Coefficient

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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