scholarly journals Varying VAWT Cluster Configuration and the Effect on Individual Rotor and Overall Cluster Performance

Energies ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1567
Author(s):  
Jeffrey E. Silva ◽  
Louis Angelo M. Danao
Keyword(s):  
Vertical Axis ◽  
Separation Distance ◽  
Test Cases ◽  
Vertical Axis Wind Turbine ◽  
Cluster Performance ◽  
Cluster Configuration ◽  
Maximum Cluster ◽  
Overall Performance ◽  
Left And Right ◽  
Equivalent Distance

The effect of separation distance between turbines on overall cluster performance were simulated using computational fluid dynamics software and we found that at a distance equivalent to two rotors, there was an improvement of +8.06% in the average performance of the cluster compared to a single, isolated turbine. A very small improvement in performance was noted at the equivalent distance of 12 rotor diameters. The performances of three individual turbines in pyramid- and inverted pyramid-shaped vertical axis wind turbine clustered farm configurations with varying oblique angles at a fixed spacing of two equivalent rotor diameters were also investigated. The design experiment involves the simulation of test cases with oblique angles from 15° to 165° at an interval of 15° and the turbines were allowed to rotate through 18 full rotations. The results show that the left and right turbines increase in performance as the angle with respect to the streamline axis increases, with the exception of the 165° angle. The center turbine, meanwhile, attained its maximum performance at a 45° oblique angle. The maximum cluster performance was found to be in the configuration where the turbines were oriented in a line (i.e., side by side) and perpendicular to the free-stream wind velocity, exhibiting an overall performance improvement of 9.78% compared to the isolated turbine. Other array configurations show improvements ranging from 6.58% to 9.57% compared to the isolated turbine, except in the extreme cases of 15° and 165°, where a decrease in the cluster performance was noted due to blockage induced by the left and right turbines, and the center turbines, respectively.

CFD Investigation of the Multiple Rotors Darrieus Type Turbine Performance

2019 ◽  
Author(s):  
Omar Sherif Mohamed ◽  
Ahmed Ibrahim ◽  
Ahmed M. R. El Baz
Keyword(s):  
Urban Areas ◽  
Low Cost ◽  
Vertical Axis ◽  
Power Coefficient ◽  
Vertical Axis Wind Turbine ◽  
Cfd Simulations ◽  
Close Proximity ◽  
Horizontal Axis Wind Turbines ◽  
Computational Fluid Dynamics Cfd ◽  
Overall Performance

Abstract The last few years have witnessed researches concerned by vertical axis wind turbine (VAWT) performance considering its advantages compared to the horizontal axis wind turbines, as it can be operated in urban areas without producing noise, ease of maintenance and simple construction, in addition to its low cost. More interest is growing in developing efficient clusters of VAWT in order to increase power generation at specific sites by using multiple turbines. In the present work, the performance of various configurations of Darrieus type VAWT clusters is examined using computational fluid dynamics (CFD) simulations. The objective of this work is to increase the overall power coefficient of the turbines cluster compared to single rotor performance. This objective shall be achieved by examining mutual interactions between rotors arranged in close proximity and examining the effect of oblique angle between rotors on overall performance of the cluster of rotors. The performance is assessed by observing the overall power coefficient of the cluster. Also, the velocity wake of the simulated three rotors turbine cases was analyzed and compared to the that of the single rotor.

Vibration Response Behaviour of a High Solidity, Low Rotational Velocity, Vertical Axis Wind Turbine

2010 ◽  
Author(s):  
Kevin W. McLaren ◽  
Stephen W. Tullis ◽  
Samir Ziada
Keyword(s):  
Wind Turbine ◽  
Natural Frequencies ◽  
Rotational Velocity ◽  
Vertical Axis ◽  
Vibration Response ◽  
Resonance Excitation ◽  
Test Cases ◽  
Vertical Axis Wind Turbine ◽  
Aerodynamic Loading ◽  
End Conditions

A series of full scale experimental wind tunnel tests were performed to determine the aerodynamic loading behaviour on the airfoils of a high solidity, low rotational velocity, 3 bladed H-type vertical axis wind turbine. The primary vibration response was resonance excitation of the dominant whirling mode of the turbine. However, for a significant number of test cases, resonance behaviour was also observed in the bending strains of the airfoil support struts, primarily corresponding to higher natural frequencies. Furthermore, under various test conditions, vibration amplitude within the support struts was observed to change dramatically during a single test run, suggesting that the vibration was jumping between sets of airfoil support struts in a complex beating mode. In order to isolate the numerous vibration excitation and response behaviours, tests were performed over a range of flow velocities from 8 m/s to 11 m/s with two different support shaft end conditions.

Performance Predictions of a Circulation Controlled-Vertical Axis Wind Turbine With Solidity Control

2009 ◽  
Author(s):  
Jay P. Wilhelm ◽  
Emily D. Pertl ◽  
Franz A. Pertl ◽  
James E. Smith
Keyword(s):  
Wind Turbine ◽  
Vertical Axis ◽  
Speed Ratio ◽  
Vertical Axis Wind Turbine ◽  
Tip Speed Ratio ◽  
Vertical Axis Wind Turbines ◽  
Performance Predictions ◽  
Overall Performance ◽  
And Control ◽  
Selection Of

Conventional straight bladed vertical axis wind turbines are typically designed to produce maximum power at tip speed ratio, but power production can suffer when operating outside of the design range. These turbines, unless designed specifically for low speed operation, may require rotational startup assistance. Circulation control methods, such as using blowing slots on the trailing edge could be applied to a Vertical Axis Wind Turbine (VAWT) blade. Improvements to the amount of power developed at lower speeds and elimination or reduction of startup assistance could be possible with this lift augmentation. Selection of a beneficial rotor solidity and control over when to utilize the blowing slots for the CC-VAWT (Circulation Controlled-Vertical Axis Wind Turbine) appears to have a profound impact on overall performance. Preliminary performance predictions indicate that at a greater range of rotor solidities, the CC-VAWT can have overall performance levels that exceed a conventional VAWT. This paper describes the performance predictions and solidity selection of a circulation controlled vertical axis wind turbine that can operate at higher overall capture efficiencies than a conventional VAWT.

scholarly journals CFD analysis on the influence of angle of attack on vertical axis wind turbine aerodynamics

2021 ◽  
Vol 850 (1) ◽  
pp. 012027
Author(s):  
Prateek Srivastava ◽  
Sachin Kansal ◽  
Ashish Talwalkar ◽  
R Harish
Keyword(s):  
Wind Turbine ◽  
Angle Of Attack ◽  
Vertical Axis ◽  
Cfd Analysis ◽  
Vertical Axis Wind Turbine ◽  
Cfd Simulations ◽  
Ansys Fluent ◽  
Wind Turbine Aerodynamics ◽  
Fluent Software ◽  
Overall Performance

Abstract The Angle of Attack (AOA) in a Vertical Axis Wind Turbine (VAWT) plays an important role in determining the forces and the power generated by the wind turbine. It is difficult to find the suitable AOA due to the complex and constantly changing wind flow patterns. In this paper, we have performed CFD simulations using Ansys Fluent software, based on the constantly changing AOA. The CFD simulations were conducted by selecting a suitable range of AOA and the velocity of the wind. The selected range of AOA varied from 5 degrees to 25 degrees with increments of 5 degrees and the range of the air velocities varied from 7m/s to 21m/s with increments of 7m/s. The tests were also performed using the X-Foil software. The results obtained from the CFD simulations, done by using the Ansys Fluent Software and from the X-Foil software, were then compared to give a more accurate and optimized AOA and velocity value. This optimization of the AOA could enhance the overall performance of the Vertical Axis Wind turbine.

Calculating the aerodynamics of vertical axis wind turbines

2012 ◽  
Vol 34 (3) ◽  
pp. 169-184 ◽  
Author(s):  
Hoang Thi Bich Ngoc
Keyword(s):  
Wind Turbine ◽  
Incidence Angle ◽  
Vertical Axis ◽  
Rotor Blades ◽  
Vertical Axis Wind Turbine ◽  
Horizontal Axis Wind Turbine ◽  
Velocity Triangle ◽  
Relationship Of ◽  
The Relationship

Vertical axis wind turbine technology has been applied last years, very long after horizontal axis wind turbine technology. Aerodynamic problems of vertical axis wind machines are discussible. An important problem is the determination of the incidence law in the interaction between wind and rotor blades. The focus of the work is to establish equations of the incidence depending on the blade azimuth, and to solve them. From these results, aerodynamic torques and power can be calculated. The incidence angle is a parameter of velocity triangle, and both the factors depend not only on the blade azimuth but also on the ratio of rotational speed and horizontal speed. The built computational program allows theoretically selecting the relationship of geometric parameters of wind turbine in accordance with requirements on power, wind speed and installation conditions.

Design and Analysis of Vertical Axis Wind Turbine

2017 ◽  
Author(s):  
Prof. R.K. Bhoyar ◽  
Prof. S.J. Bhadang ◽  
Prof. N.Z. Adakane ◽  
Prof. N.D. Pachkawade
Keyword(s):  
Wind Turbine ◽  
Vertical Axis ◽  
Vertical Axis Wind Turbine
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