scholarly journals Aerodynamic characteristics of a stationary five bladed vertical axis vane wind turbine

1970 ◽  
Vol 39 (2) ◽  
pp. 95-99 ◽  
Author(s):  
Faizul Mohammad Kamal ◽  
Md Quamrul Islam
Keyword(s):  
Wind Turbine ◽  
Dynamic Performance ◽  
Research Work ◽  
Vertical Axis ◽  
Aerodynamic Characteristics ◽  
Open Circuit ◽  
Power Coefficient ◽  
Vertical Axis Wind Turbine ◽  
Torque Coefficient ◽  
Static Torque

Drag and torque coefficients of a stationary five bladed vane type rotor have been investigated in this present research work by measuring the pressure distribution on the blade surfaces at various rotor angles. The experimental investigation has been performed at Reynolds number 1.65 x 105 in a uniform flow jet produced by an open circuit wind tunnel. It has been observed that the total static torque coefficient increases from 0° to 10°, and reaches its maximum value and then decreases up to 30°. From this point, the total static torque increases up to 72°. Total static torque coefficient at different rotor angles curve repeats from 72° to 144°, 144° to 216°, 216° to 288°, and 288° to 360° angle of rotation. A quasi-steady approach has been applied for the prediction of dynamic performance of the rotor using the static drag and torque coefficients. This method results in a fair agreement with the measured power coefficient. Keywords: Vertical axis wind turbine, vane type rotor, drag coefficient, torque coefficient. doi:10.3329/jme.v39i2.1852 Journal of Mechanical Engineering, Vol. ME39, No. 2, Dec. 2008 95-99

scholarly journals Research on Aerodynamic Characteristics of Straight-Bladed Vertical Axis Wind Turbine with S Series Airfoils

2018 ◽  
Vol 2018 ◽  
pp. 1-13 ◽  
Author(s):  
Fang Feng ◽  
Shouyang Zhao ◽  
Chunming Qu ◽  
Yuedi Bai ◽  
Yuliang Zhang ◽  
...  
Keyword(s):  
Wind Turbine ◽  
Vertical Axis ◽  
Aerodynamic Characteristics ◽  
Performance Comparison ◽  
Power Coefficient ◽  
Vertical Axis Wind Turbine ◽  
Wind Tunnel Experiments ◽  
Speed Performance ◽  
Torque Coefficient ◽  
Static Torque

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.

Application of Variable Blade Pitch Control on Improving the Performance of Vertical Axis Wind Turbine

2012 ◽  
Vol 229-231 ◽  
pp. 2339-2342
Author(s):  
J.C. Cheng ◽  
S.J Su ◽  
J.J Miau
Keyword(s):  
Wind Turbine ◽  
Vertical Axis ◽  
Aerodynamic Characteristics ◽  
Speed Ratio ◽  
Vertical Axis Wind Turbine ◽  
Energy Capture ◽  
Pitch Control ◽  
Tip Speed Ratio ◽  
Torque Coefficient ◽  
Variable Pitch Control

A three blades vertical axis wind turbine simulation is performed to study the unsteady aerodynamic characteristics with blade pitch control. Several fixed and variable blade pitch models under different tip speed ratio are adopted to improve performance of the wind turbine. Results show that an appropriate pitch control model can effectively decrease the range of negative torque regime to reduce the vibration of the wind turbine. Besides, the average torque coefficient as well as the energy capture efficiency can be also improved, especially for the lower tip speed ratio. The overall efficiency of the wind turbines in power generation will be enhanced. For the cases under the tip speed ratio between 1 and 3, the efficiency can be enhanced 243% and 486% for fixed and variable pitch control models respectively as comparing with non-pitch control cases.

Numerical Simulation on the Static Torque Performance of Vertical Axis Wind Turbine with Different Blade Airfoils

2011 ◽  
Vol 84-85 ◽  
pp. 702-705 ◽  
Author(s):  
Yan Li ◽  
Fang Feng ◽  
Wen Qiang Tian ◽  
Kotaro Tagawa
Keyword(s):  
Wind Turbine ◽  
Low Cost ◽  
Vertical Axis ◽  
Velocity Fields ◽  
Simple Design ◽  
Vertical Axis Wind Turbine ◽  
Torque Coefficient ◽  
Cfd Method ◽  
Starting Torque ◽  
Static Torque

Recently, the straight-bladed vertical axis wind turbine (SB-VAWT) receives more and more attentions for its simple design, low cost, and good maintenance. The torque performance of the SB-VAWT is greatly affected by the blade airfoil. In order to research the static torque characteristics of SB-VAWT with symmetrical and non-symmetrical blade airfoil, numerical simulations by 2D CFD method were carried out on three kinds of blade airfoils including NACA0018, NACA2418 and NACA4418 at different azimuth angles. Furthermore, the static torque coefficient of the SB-VAWT with four blades with the three kinds of blade airfoils was calculated. The pressure and velocity fields were also obtained to analyze the static torque performance. Based on these results, the effects of blade airfoils on the starting torque performance of the SB-VAWT were compared and discussed.

scholarly journals Studi Eksperimen Pengaruh Jumlah Sudu Terhadap Kinerja Wind Turbine Crossflow

2021 ◽  
Vol 16 (2) ◽  
pp. 218
Author(s):  
Fahrudin Fahrudin ◽  
Fitri Wahyuni ◽  
Dini Oktavitasari
Keyword(s):  
Wind Turbine ◽  
Alternative Energy ◽  
Wind Tunnel Test ◽  
Vertical Axis ◽  
Power Coefficient ◽  
Speed Ratio ◽  
Test Scheme ◽  
Vertical Axis Wind Turbine ◽  
Tip Speed Ratio ◽  
Torque Coefficient

<p>Wind is an alternative energy that is environmentally friendly and sustainable. Therefore, we need a type of wind turbine that can receive wind from all directions. The crossflow type vertical axis wind turbine has a high torque coefficient at a low tip speed ratio. The purpose of this study was to determine the effect of the number of blades on the performance of the vertical axis crossflow wind turbine. The experimental test was carried out by varying the number of blades. The configuration is analyzed using the experimental wind tunnel test scheme which has been modified in the section test section. The results showed that the number of blades 16 has a power coefficient ( ) = 0.23 tip speed ratio (TSR) = 0.42 at a wind speed of 4 m / s.</p><p><strong><br /></strong></p>

scholarly journals Effect of Auxiliary Blade on Aerodynamic Characteristics of Vertical Axis Wind Turbine by Numerical Simulation

2019 ◽  
Vol 2019 ◽  
pp. 1-17
Author(s):  
Yan Li ◽  
Chang Zhao ◽  
Chunming Qu ◽  
Shouyang Zhao ◽  
Fang Feng ◽  
...  
Keyword(s):  
Wind Turbine ◽  
Output Power ◽  
Vertical Axis ◽  
Aerodynamic Characteristics ◽  
Vertical Axis Wind Turbine ◽  
Relative Thickness ◽  
Power Characteristics ◽  
Blade Section ◽  
Static Conditions ◽  
Static Torque

In order to improve the aerodynamic characteristics of the Straight-bladed Vertical Axis Wind Turbine (SB-VAWT), a rotor structure with auxiliary blade installed behind the main blade was proposed in this study. To investigate the effects of relative thickness and the fixing angle of the auxiliary blade on aerodynamic characteristics of SB-VAWT, numerical simulations were carried out. Two shapes of NACA 4-digital series blade-section, NACA0018 and NACA0024, were selected as the main blades in this work. Effects of relative thickness and fixing angles of auxiliary blade on the aerodynamic performance of SB-VAWT had been analyzed in detail, which had 5 kinds of relative thickness and 3 kinds of fixing angles combined into 13 working conditions. And the main blades and the auxiliary blades were also decided as the NACA series airfoil with five kinds of relative thickness. Three kinds of fixing angle of auxiliary blade installed behind main blade were used including 0°, 5°, and 10°. The simulations included the output power coefficients, the static torque coefficients, and the flow fields around the main blade and auxiliary blade for both the dynamic and static conditions at some typical azimuth angles. The results show that the auxiliary blade with certain relative thickness and fixing angle can improve the output power characteristics and static torque characteristics of SB-VAWT, which can also provide research reference for improving the performance of VAWT.

scholarly journals Numerical Investigation on the Effects of Airfoil Leading Edge Radius on the Aerodynamic Performance of H-Rotor Darrieus Vertical Axis Wind Turbine

Energies ◽  
2019 ◽  
Vol 12 (19) ◽  
pp. 3794
Author(s):  
Chenguang Song ◽  
Guoqing Wu ◽  
Weinan Zhu ◽  
Xudong Zhang ◽  
Jicong Zhao
Keyword(s):  
Wind Turbine ◽  
Leading Edge ◽  
Vertical Axis ◽  
Aerodynamic Characteristics ◽  
Power Coefficient ◽  
Speed Ratio ◽  
Vertical Axis Wind Turbine ◽  
Edge Radius ◽  
Flow Field Characteristics ◽  
Naca 0015

This paper numerically investigates the effects of airfoil leading edge radius on the aerodynamic characteristics of H-rotor Darrieus vertical axis wind turbine (VAWT). 10 modified airfoils are generated by changing the leading edge radius of the base NACA 0015 airfoil from 1%c to 9%c, respectively. A 2D unsteady Computational Fluid Dynamics (CFD) model is established and validated with the previously published experimental data. The power, torque, and flow field characteristics of the rotors are analyzed. The results indicate that the maximum and minimum power coefficient at the optimum tip speed ratio (TSR) are obtained for the LE-5%c and LE-1%c model, respectively. The best aerodynamic characteristics are determined by the LE-5%c model below the optimum TSR and the LE-3%c model beyond the optimum TSR. The torque characteristics and pressure distribution for the single blades with different airfoil leading edge radius show an obvious difference in the upwind region and a very small difference in the downwind region. Moreover, the airfoil leading edge radius influences the strength, region, and diffusion rate of the vortices, being the main reason for the observed differences in instantaneous torque coefficient and power coefficient. The vortices of the LE-1%c model are stronger, larger, and diffuse slower than those of the LE-2%c and LE-5%c model at the optimum TSR.

Influence of Phase-Shift and Overlap Ratio on Savonius Wind Turbine’s Performance

2011 ◽  
Vol 134 (1) ◽  
Author(s):  
Chen Jian ◽  
Jan Kumbernuss ◽  
Zhang Linhua ◽  
Lu Lin ◽  
Yang Hongxing
Keyword(s):  
Phase Shift ◽  
Vertical Axis ◽  
Power Coefficient ◽  
Easy Access ◽  
Vertical Axis Wind Turbine ◽  
Two Stage ◽  
Phase Shift Angle ◽  
Torque Coefficient ◽  
Overlap Ratio ◽  
Static Torque

This paper presents the experimental results of the vertical axis wind turbine (VAWT), especially the Savonius rotors, which are developed for application on top of buildings due to lower wind speed compared with remote areas. The VAWT is regarded as the most suitable elegant candidate to be integrated with buildings for its relatively low operating noise, easy maintenance, and easy access. This study explored the interaction effect of the overlap ratio, phase-shift, and stage on the performance of the Savonius rotors in details. The results show that appropriate choice of the phase-shift angle according to the overlap ratio can not only increase the power coefficient of the Savonius rotors but also eliminate the negative static torque and smooth the variation of the static torque coefficient. Moreover, the performance of the two-stage rotors indicates that the two-stage rotor is the best candidate for this type of wind turbines or as a starting assistant for the Darrieus rotors.

scholarly journals MODELING AND SIMULATION OF THE VERTICAL AXIS WIND TURBINE BY QBLADE SOFTWARE

2020 ◽  
Vol 2 (02) ◽  
pp. 181-188
Author(s):  
MERAD ◽  
Asmae BOUANANI ◽  
Mama BOUCHAOUR
Keyword(s):  
Wind Energy ◽  
Wind Turbine ◽  
Wind Turbines ◽  
Urban Areas ◽  
Clean Energy ◽  
Vertical Axis ◽  
Aerodynamic Characteristics ◽  
Simulation Software ◽  
Power Coefficient ◽  
Vertical Axis Wind Turbine

The use of wind energy has no harmful effects on the environment. This makes it a clean energy that is a real alternative to the problem of nuclear waste management and greenhouse gas emissions. Vertical axis wind turbines have prospective advantages in the field of domestic applications, because they have proven effectual in urban areas where wind flow conditions are intermittent, omnidirectional, unsteady and turbulent. The wind cannot ensure a regular energy supply without optimising the aerodynamics of the blades. This article presents a reminder about wind energy and wind turbines, especially the VAWT type wind turbines and also gives a presentation on the aerodynamic side of VAWT by studying the geometry and aerodynamic characteristics of the blade profiles with the acting forces and also the explanation of the DMS multiple flow tube model. This work also gives the different simulation methods to optimize the behaviour of the blades from the selected NACA profiles; the analysis first goes through the design of the blades by the design and simulation software Qblade which is used to calculate also the forces on the blade and the coefficients of lift, drag and fineness. At the end of this article we have the DMS simulation of the VAWT turbines, by determining the power coefficient and the power collected by the turbine to select the wind turbine adapted to a well characterized site.

Aerodynamic and aeroacoustic performance investigations on modified H-rotor Darrieus wind turbine

2021 ◽  
pp. 0309524X2110039
Author(s):  
Amgad Dessoky ◽  
Thorsten Lutz ◽  
Ewald Krämer
Keyword(s):  
Wind Turbine ◽  
High Speed ◽  
Cfd Simulation ◽  
Vertical Axis ◽  
3D Models ◽  
Power Coefficient ◽  
Design Parameters ◽  
Second Phase ◽  
Vertical Axis Wind Turbine ◽  
Guide Vanes

The present paper investigates the aerodynamic and aeroacoustic characteristics of the H-rotor Darrieus vertical axis wind turbine (VAWT) combined with very promising energy conversion and steering technology; a fixed guide-vanes. The main scope of the current work is to enhance the aerodynamic performance and assess the noise production accomplished with such enhancement. The studies are carried out in two phases; the first phase is a parametric 2D CFD simulation employing the unsteady Reynolds-averaged Navier-Stokes (URANS) approach to optimize the design parameters of the guide-vanes. The second phase is a 3D CFD simulation of the full turbine using a higher-order numerical scheme and a hybrid RANS/LES (DDES) method. The guide-vanes show a superior power augmentation, about 42% increase in the power coefficient at λ = 2.75, with a slightly noisy operation and completely change the signal directivity. A remarkable difference in power coefficient is observed between 2D and 3D models at the high-speed ratios stems from the 3D effect. As a result, a 3D simulation of the capped Darrieus turbine is carried out, and then a noise assessment of such configuration is assessed. The results show a 20% increase in power coefficient by using the cap, without significant change in the noise signal.

Numerical Study of Pitch Angle on H-Type Vertical Axis Wind Turbine

2012 ◽  
Vol 499 ◽  
pp. 259-264
Author(s):  
Qi Yao ◽  
Ying Xue Yao ◽  
Liang Zhou ◽  
S.Y. Zheng
Keyword(s):  
Wind Turbine ◽  
Pitch Angle ◽  
Numerical Study ◽  
Vertical Axis ◽  
Azimuth Angle ◽  
Power Coefficient ◽  
Cfd Model ◽  
Vertical Axis Wind Turbine ◽  
Sliding Mesh ◽  
Mesh Technique

This paper presents a simulation study of an H-type vertical axis wind turbine. Two dimensional CFD model using sliding mesh technique was generated to help understand aerodynamics performance of this wind turbine. The effect of the pith angle on H-type vertical axis wind turbine was studied based on the computational model. As a result, this wind turbine could get the maximum power coefficient when pitch angle adjusted to a suited angle, furthermore, the effects of pitch angle and azimuth angle on single blade were investigated. The results will provide theoretical supports on study of variable pitch of wind turbine.

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