scholarly journals Observation of the Starting and Low Speed Behavior of Small Horizontal Axis Wind Turbine

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Sikandar Khan ◽  
Kamran Shah ◽  
Izhar-Ul-Haq ◽  
Hamid Khan ◽  
Sajid Ali ◽  
...  
Keyword(s):  
Wind Turbine ◽  
Wind Turbines ◽  
Horizontal Axis ◽  
Horizontal Axis Wind Turbine ◽  
Wind Speeds ◽  
Starting Time ◽  
Speed Range ◽  
Horizontal Axis Wind Turbines ◽  
Starting Torque ◽  
High Angles Of Attack

This paper describes the starting behavior of small horizontal axis wind turbines at high angles of attack and low Reynolds number. The unfavorable relative wind direction during the starting time leads to low starting torque and more idling time. Wind turbine models of sizes less than 5 meters were simulated at wind speed range of 2 m/s to 5 m/s. Wind turbines were modeled in Pro/E and based on the optimized designs given by MATLAB codes. Wind turbine models were simulated in ADAMS for improving the starting behavior. The models with high starting torques and less idling times were selected. The starting behavior was successfully improved and the optimized wind turbine models were able to produce more starting torque even at wind speeds less than 5 m/s.

Analysis on Aerodynamic Performance of Horizontal Axis Wind Turbine Based on Nonlinear Wake Model

2013 ◽  
Vol 448-453 ◽  
pp. 1716-1720
Author(s):  
Rui Yang ◽  
Jiu Xin Wang ◽  
Sheng Long Zhang
Keyword(s):  
Wind Turbine ◽  
Wind Turbines ◽  
Optimization Design ◽  
Aerodynamic Performance ◽  
Horizontal Axis ◽  
Wake Vortex ◽  
Horizontal Axis Wind Turbine ◽  
Horizontal Axis Wind Turbines ◽  
Wake Model ◽  
Induced Velocity

A computational method based on nonlinear wake model was established for horizontal axis wind turbines aerodynamic performance prediction. This method makes use of finite difference method to solve the integral differential equation of the model, the induced velocity of wake vortex can be calculated from equations and compared with the induced velocity of wake vortex in linear model. The comparison between the calculated results of wind turbine under axis flow condition, including tip vortex geometry and aerodynamic performance, and available experimental data shows that this method is suitable for wind turbine aerodynamic performance analysis. Finally, a series of numerical calculations were made to investigate the change of wake geometry and aerodynamic performance of the wind turbine when yawing and pitch angle increasing, which provide foundations for aerodynamic optimization design of horizontal axis wind turbines.

scholarly journals Establishing a robust testing approach for displacement measurement on a rotating horizontal-axis wind turbine

2018 ◽  
Vol 3 (1) ◽  
pp. 301-311
Author(s):  
Nadia Najafi ◽  
Allan Vesth
Keyword(s):  
Wind Turbine ◽  
Camera Calibration ◽  
Wind Turbines ◽  
Calibration Method ◽  
Horizontal Axis ◽  
Tracking Algorithm ◽  
Displacement Measurement ◽  
Horizontal Axis Wind Turbine ◽  
Damage And Failure ◽  
Horizontal Axis Wind Turbines

Abstract. Health monitoring by conventional sensors like accelerometers or strain gauges becomes challenging for large rotating structures due to the issues with feasibility, sensing and data transmission. In addition, acceleration measurements have low capability of presenting very small frequencies, which happen very often for large structures (for instance, frequencies between 0.2 and 0.5 Hz in horizontal-axis wind turbines). By contrast, displacement measurement using stereo vision is rapid, non-contacting and distributed over the structure. The sensors are cheaper and more easily applied to many places on the object to be measured. Horizontal-axis wind turbines are one of the most important large rotating structures and need to be measured and monitored in time to prevent damage and failure, and the blade tip position is one of the key parameters to measure in order to prevent the blade hitting the turbine tower. This paper presents a clearly described and easily applicable procedure for measuring the displacement on the components of a rotating horizontal-axis wind turbine with stereophotogrammetry. Paper markers have been applied on the rotor and tower of a scaled-down horizontal-axis wind turbine model in the workshop and the displacement measurement method has been demonstrated by measuring displacement during operation. The method is mainly developed in two parts: (1) camera calibration and (2) tracking algorithm. We introduce an efficient camera calibration method for measurement in large fields of view, which has always been a challenge. This method is easy and practical and offers better accuracy compared with 2-D traditional camera calibration. The tracking algorithm also works successfully and is able to track the points during rotation within the measurement time. Finally, the accuracy analysis has been conducted and has shown better accuracy of the new calibration method compared with 2-D traditional camera calibration.

scholarly journals Designing a Tapperless Blade with an S-4320 Airfoil on a Micro-Scale Horizontal Axis Wind Turbine (Case Studies at PT Lentera Bumi Nusantara)

2021 ◽  
Vol 3 (1) ◽  
pp. 27-34
Author(s):  
Reza Simatupang ◽  
Deddy Supriatna
Keyword(s):  
Wind Turbine ◽  
Quantitative Research ◽  
Horizontal Axis ◽  
Blade Design ◽  
Horizontal Axis Wind Turbine ◽  
Microsoft Excel ◽  
Quantitative Research Methods ◽  
Micro Scale ◽  
Wind Speeds ◽  
Horizontal Axis Wind Turbines

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.

scholarly journals Modified Design of Savonius Wind Turbine Blade for Performance Improvement

2019 ◽  
Vol 9 (1) ◽  
pp. 1432-1437
Keyword(s):  
Wind Turbine ◽  
Wind Turbines ◽  
New Technologies ◽  
Vertical Axis ◽  
Horizontal Axis ◽  
Wind Speeds ◽  
Wind Potential ◽  
Horizontal Axis Wind Turbines ◽  
Savonius Wind Turbine ◽  
Low Performance

In the context of worldwide energetic transition, wind energy shows up as one of the most prominent renewable energy to provide an alternative for the conventional energy source. Therefore, new technologies of a wind turbine are developed, horizontal axis wind turbines have been extensively investigated and evolved. However, the development of vertical axis wind turbines is still an open and area of research, The main objective is to develop a more efficient type of wind turbines able to operate at low wind speeds to take hold maximum wind potential, The Savonius rotor goes with such conditions, however, it faces critical drawbacks, in particular, the low performance in comparison with horizontal axis wind turbines, as well, the blade in return of savonius wind turbine generates a negative torque leading to a decrement of turbine performance. The present work aims to investigate a modified model of the conventional Savonius rotors with a focus on improving the coefficient of power, transient computational fluid dynamics (CFD) simulations are carried out in an effort to perform a validation of numerical results according to experimental data, also to conduct a comparative analysis of both savonius models

Performance Enhancement of Horizontal Axis Wind Turbine Using Numerical Techniques

2021 ◽  
Author(s):  
Poornima Menon ◽  
Srinivas G
Keyword(s):  
Wind Turbine ◽  
Wind Turbines ◽  
Performance Enhancement ◽  
Horizontal Axis ◽  
Horizontal Wind ◽  
Horizontal Axis Wind Turbine ◽  
Ansys Fluent ◽  
Horizontal Axis Wind Turbines ◽  
Design Requirements ◽  
Nrel Phase Vi

Abstract Wind turbines are one of the most prominent and popular sources of renewable energy, of which, horizontal axis wind turbines (HAWT) are the majorly chosen design for wind machines. These turbines rotate about the horizontal axis which is parallel to the ground. They comprise of aerodynamic blades (generated from the desired airfoil), that may be twisted or tapered as per the design requirements. The blades are attached to a rotor which is located either upwind or downwind. To help wind the orientation of the turbines, the upwind rotors have a tail vane, while the downwind rotors are coned which in turn help them to self-orient. One of the major reasons for the popularity of the horizontal wind turbine, is its ability to generate a larger amount of electricity for a given amount of wind. Due to its popularity, the enhancement in the design of HAWTs, is a major focus area for research. In the present study, a scaled-down CFD model of the NREL Phase VI was validated against the numerical and experimental data. The model used had a dual blade rotor and applied the S809 airfoil. The simulations were carried out using a rotating mesh in ANSYS Fluent. Validation was carried out for 3 velocities — 7m/s, 10m/s and 20m/s. Once validation was carried out, turbine was modified with the addition of vortex generators, in the form of cylindrical protrusions that reduce flow separation.

Aerodynamic Performance of a Small Horizontal Axis Wind Turbine

2012 ◽  
Vol 134 (2) ◽  
Author(s):  
Maryam Refan ◽  
Horia Hangan
Keyword(s):  
Wind Turbine ◽  
Wind Turbines ◽  
High Speed ◽  
Aerodynamic Performance ◽  
Horizontal Axis ◽  
Power Prediction ◽  
Horizontal Axis Wind Turbine ◽  
Wind Speeds ◽  
Wide Range ◽  
Bem Theory

The aerodynamic performance of an upwind, three-bladed, small horizontal axis wind turbine (HAWT) rotor of 2.2 m in diameter was investigated experimentally and theoretically in order to assess the applicability of the blade element momentum (BEM) theory for modeling the rotor performance for the case of small HAWTs. The wind turbine has been tested in the low and high speed sections of the Boundary Layer Wind Tunnel 2 (BLWT2) at the University of Western Ontario (UWO) in order to determine the power curve over a wide range of wind speeds. Afterward, the BEM theory has been implemented to evaluate the rotor performance and to investigate three-dimensionality effects on power prediction by the theory. Comparison between the theoretical and experimental results shows that the overall prediction of the theory is within an acceptable range of accuracy. However, the BEM theory prediction for the case of small wind turbines is not as accurate as the prediction for larger wind turbines.

Robust Design of Horizontal Axis Wind Turbines Using Taguchi Method

2015 ◽  
Author(s):  
Singiresu S. Rao
Keyword(s):  
Taguchi Method ◽  
Wind Turbine ◽  
Robust Design ◽  
Wind Turbines ◽  
Horizontal Axis ◽  
Parameter Design ◽  
Energy Output ◽  
Horizontal Axis Wind Turbine ◽  
Momentum Theory ◽  
Horizontal Axis Wind Turbines

The robust design of horizontal axis wind turbines, including both parameter and tolerance designs, is presented. A simple way of designing robust horizontal axis wind turbine systems under realistic conditions is outlined with multiple design variables, multiple objectives, and multiple constraints simultaneously by using the traditional Taguchi method and its extensions. The performance of the turbine is predicted using the axial momentum theory and the blade element momentum theory. In the parameter design stage, the energy output of the turbine is maximized using the Taguchi method and an extended penalty-based Taguchi method is proposed to solve constrained parameter design problems. Using an appropriate set of tolerance settings of the parameters, the tolerance design problem is formulated so as to yield an economical design while ensuring a minimal variability in the performance of the wind turbine. The present work provides a simple and economical approach for the robust optimal design of horizontal axis wind turbines.

Effect of Wind Shear to Horizontal Axis Wind Turbine Aerodynamic

2014 ◽  
Vol 521 ◽  
pp. 99-103
Author(s):  
Ling Zhang ◽  
Hui Xia Sheng ◽  
Da Fei Guo
Keyword(s):  
Wind Turbine ◽  
Wind Turbines ◽  
Wind Shear ◽  
Numerical Study ◽  
Three Dimensional ◽  
Horizontal Axis ◽  
Power Calculation ◽  
Horizontal Axis Wind Turbine ◽  
Horizontal Axis Wind Turbines ◽  
And Performance

A three-dimensional unsteady numerical study of the streaming flow field of the1.2 MW horizontal axis wind turbines which operation in the 11.26 m/s under the uniform wind and the shear wind have been carried out in this paper. according to the simulation results to understand the effect of uniform flow and the dynamic wind shear flow to the output power of wind turbine and the aerodynamics. results showed that: Under the uniform wind,Wind turbine power calculation values are in good agreement with the design value ,Wind turbines under the influence of wind shear can lead to change in load and performance on the surface of the blade.

scholarly journals New System for the Acceleration of the Airflow in Wind Turbines

2019 ◽  
Vol 12 (2) ◽  
pp. 158-167
Author(s):  
Alejandro Alonso-Estébanez ◽  
Pablo Pascual-Muñoz ◽  
Felipe P. Alvarez Rabanal ◽  
Daniel Castro-Fresno ◽  
Juan J. Del Coz Díaz
Keyword(s):  
Wind Turbine ◽  
Wind Turbines ◽  
Horizontal Axis ◽  
Horizontal Axis Wind Turbine ◽  
The Earth ◽  
Air Stream ◽  
Free Air ◽  
Prevailing Wind Direction ◽  
Horizontal Axis Wind Turbines ◽  
Wind Resource

Background: This patent is based on the wind industry technology called Diffuser Augmented Wind Turbines (DAWTs). This technology consists of a horizontal axis wind turbine, which is housed inside a duct with diverging section in the direction of the free air stream. In this paper, a review of preceding patents related to this technology is carried out. Objective: This paper presents an innovative patent to improve the performance of horizontal axis wind turbines. In particular, this system is aimed at improving the performance of those turbines that otherwise might not be installed due to the low wind resource existing at certain locations. Methods: The most innovative elements of this patent are: (1) the semi-spherical grooves, which are mechanized on the surface of the two diffusers in order to guarantee a more energetic boundary layer; (2) the coaxial diffuser, which is located downwind following the first diffuser in order to increase the suction effect on the air mass close to the inlet; (3) the coaxial rings located around the first diffuser outlet, which are used to deflect the external airflow toward the turbine wake; and (4), the selforientating system to orientate the system by the prevailing wind direction. Results: An application of the patent for increasing the power generated by a horizontal axis wind turbine with three blades is presented. The patent is designed and its performance is evaluated by using a Computational Fluid Dynamics code. The numerical results show that this system rises the airflow going through the rotor of the turbine. Conclusion: The patented device is an original contribution aimed at enabling a more profitable installation of wind turbines in places where the wind resource is insufficient because of the wind shear caused both by the proximity of the earth and the obstacles on the earth surface.

scholarly journals Establishing a robust testing approach for displacement measurement on a rotating horizontal axis wind turbine

2017 ◽  
Author(s):  
Nadia Najafi ◽  
Allan Vesth
Keyword(s):  
Wind Turbine ◽  
Camera Calibration ◽  
Wind Turbines ◽  
Calibration Method ◽  
Horizontal Axis ◽  
Tracking Algorithm ◽  
Displacement Measurement ◽  
Large Field ◽  
Horizontal Axis Wind Turbine ◽  
Horizontal Axis Wind Turbines

Abstract. Health monitoring by conventional sensors like accelerometers or strain gauges becomes challenging for large rotating structures due to the feasibility, sensing and data transmission. In addition acceleration measurements have low capability in presenting very small frequencies which happen so often for large structures (For instance frequencies between 0.2 and 0.5 Hz in horizontal axis wind turbines). By contrast the displacement measurement using stereo vision is rapid, non-contacting and also distributed over the structure. The sensors are cheaper and easier to be applied in many places on the object to be measured. Horizontal axis wind turbines are one of the important large rotating structures which need to be measured and monitored in time to prevent damage and failure and the blade tip position is one of the key parameters to measure to prevent blade hitting the turbine tower. This paper presents a well-defined procedure for measuring the displacement on the components of a rotating horizontal axis wind turbine (HAWT) with stereo photometry. Paper markers have been applied on the rotor and tower of a scaled down HAWT model in the workshop and the displacement measurement method has been demonstrated by measuring displacement during operation. The method is mainly developed in two parts: (1) the camera calibration and (2) tracking algorithm. We introduce an efficient camera calibration method for measurement in the large field of views that has always been a challenge. This method is easy and practical and offers better accuracy compared with 2D traditional camera calibration. The tracking algorithm also worked quite successfully and kept tracking the points during rotation within the measurement time.Finally the accuracy analysis has been conducted and has shown the better accuracy of the new calibration method compared with 2D traditional camera calibration.

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