Blade Profile Selection of Vertical Axis Wind Turbines for Low Wind Speed Potential Regions

2019 ◽  
Author(s):  
Pragyan Jain ◽  
Nagendra S.V. H. ◽  
Abhineet Singh ◽  
Sonali Mitra
Keyword(s):  
Wind Speed ◽  
Wind Turbines ◽  
Vertical Axis ◽  
Blade Profile ◽  
Low Wind Speed ◽  
Vertical Axis Wind Turbines ◽  
Selection Of

scholarly journals Analysis of the Patent of a Protective Cover for Vertical-Axis Wind Turbines (VAWTs): Simulations of Wind Flow

2020 ◽  
Vol 12 (18) ◽  
pp. 7818
Author(s):  
Jose Alberto Moleón Baca ◽  
Antonio Jesús Expósito González ◽  
Candido Gutiérrez Montes
Keyword(s):  
Wind Speed ◽  
Wind Turbine ◽  
Wind Turbines ◽  
High Speed ◽  
Experimental Tests ◽  
Weather Conditions ◽  
Vertical Axis ◽  
Good Alternative ◽  
Wind Speeds ◽  
Vertical Axis Wind Turbines

This paper presents a numerical and experimental analysis of the patent of a device to be used in vertical-axis wind turbines (VAWTs) under extreme wind conditions. The device consists of two hemispheres interconnected by a set of conveniently implemented variable section ducts through which the wind circulates to the blades. Furthermore, the design of the cross-section of the ducts allows the control of the wind speed inside the device. These ducts are intended to work as diffusers or nozzles, depending on the needs of the installation site. Simulations were performed for the case of high-speed external wind, for which the ducts act as diffusers to reduce wind speed and maintain a well-functioning internal turbine. Four different patent designs were analyzed, focusing on turbine performance and generated power. The results indicate that the patent allows the generation of electric power for a greater range of wind speeds than with a normal wind turbine. The results support that this patent may be a good alternative for wind power generation in geographic areas with extreme weather conditions or with maintained or strong gusty wind. Experimental tests were carried out on the movement of the blades using the available model. Finally, the power curve of the model of this wind turbine was obtained.

scholarly journals Formulation, Validation, and Application of a Novel 3D BEM Tool for Vertical Axis Wind Turbines of General Shape and Size

2021 ◽  
Vol 11 (13) ◽  
pp. 5874
Author(s):  
Andrea G. Sanvito ◽  
Vincenzo Dossena ◽  
Giacomo Persico
Keyword(s):  
Wind Tunnel ◽  
Wind Turbines ◽  
Three Dimensional ◽  
Vertical Axis ◽  
Small Scale ◽  
Engineering Practice ◽  
Blade Profile ◽  
General Shape ◽  
Vertical Axis Wind Turbines ◽  
Shape And Size

Low order models based on the Blade Element Momentum (BEM) theory exhibit modeling issues in the performance prediction of Vertical Axis Wind Turbines (VAWT) compared to Computational Fluid Dynamics, despite the widespread engineering practice of such methods. The present study shows that the capability of BEM codes applied to VAWTs can be greatly improved by implementing a novel three-dimensional set of high-order corrections and demonstrates this by comparing the BEM predictions against wind-tunnel experiments conducted on three small-scale VAWT models featuring different rotor design (H-shaped and Troposkein), blade profile (NACA0021 and DU-06-W200), and Reynolds number (from 0.8×105 to 2.5×105). Though based on the conventional Double Multiple Stream Tube (DMST) model, the here-presented in-house BEM code incorporates several two-dimensional and three-dimensional corrections including: accurate extended polar data, flow curvature, dynamic stall, a spanwise-distributed formulation of the tip losses, a fully 3D approach in the modeling of rotors featuring general shape (such as but not only, the Troposkein one), and accounting for the passive effects of supporting struts and pole. The detailed comparison with experimental data of the same models, tested in the large-scale wind tunnel of the Politecnico di Milano, suggests the very good predictive capability of the code in terms of power exchange, torque coefficient, and loads, on both time-mean and time-resolved basis. The peculiar formulation of the code allows including in a straightforward way the usual spanwise non-uniformity of the incoming wind and the effects of skew, thus allowing predicting the turbine operation in a realistic open-field in presence of the environmental boundary layer. A systematic study on the operation of VAWTs in multiple environments, such as in coastal regions or off-shore, and highlighting the sensitivity of VAWT performance to blade profile selection, rotor shape and size, wind shear, and rotor tilt concludes the paper.

scholarly journals Study on performance of a savonius wind turbines related with the blade angle

2019 ◽  
Vol 1 (2) ◽  
pp. 32-36
Author(s):  
Saowalak Thongdee ◽  
Churat Tararuk ◽  
Natthawud Dussadee ◽  
Rameshprabu Ramaraj ◽  
Tanate Chaichana
Keyword(s):  
Wind Speed ◽  
Wind Turbines ◽  
Vertical Axis ◽  
Speed Ratio ◽  
Blade Angle ◽  
Tip Speed Ratio ◽  
Vertical Axis Wind Turbines ◽  
Torque Coefficient ◽  
Savonius Wind Turbine ◽  
Positive Effect

This research aimed to compare the performance of Savonius vertical axis wind turbines through blade numbers and different blade angles. In this study, applicable turbines having 4, 6, 8, 12, 16 and 18 numbers of blades with the angles of the blades of -15°, -5°, 0°, 5° and 15°, respectively. The rotor used was a semicircle shaped blade made from PVC material and has a blade diameter of 6 cm and 30 cm for both rotor diameter and height. The turbine was tested deadweight range of 0-0.49 kg at 4 m/s wind speed. The results showed that the blade angle has a positive effect on increasing the power and torque coefficient of Savonius wind turbine, specifically on blades less than 16. The highest power and torque coefficient was obtained from the turbine having16 blades at an angle of 5°. This configuration also found that the maximum power and torque coefficient in the tip speed ratio ranging from 0.3-0.4 are 0.2519 and 0.5858, respectively.

A Pilot Study of Vertical-Axis Turbine Wind Farm Layout Planning

2014 ◽  
Vol 953-954 ◽  
pp. 395-399 ◽  
Author(s):  
Lih Shyng Shyu
Keyword(s):  
Wind Speed ◽  
Wind Turbines ◽  
Wind Farm ◽  
Wind Tunnel Test ◽  
Vertical Axis ◽  
Vertical Axis Wind Turbines ◽  
Harvesting Efficiency ◽  
Energy Harvesting Efficiency ◽  
The Cost ◽  
Turbine Output

The purpose of this study is to investigate the parameters that affect the cost-effectiveness of wind farm land use and wind energy harvesting efficiency. The research team applies two reverse rotating vertical-axis wind turbines (VAWTs) to explore how wind speed and various distances of wind turbines affect the operation efficiency of a prospective wind farm. A data acquisition system has been constructed to record the wind speed along with a variety of wind turbine output data in a wind tunnel test in order to identify the layout that help to achieve the best wind harvesting efficiency. The layout is then applied in the field test for further observation and data collection. The experiment results show 1) when two VAWTs are moved toward each other (from 300 cm to 180 cm), both turbines observe performance gain, and 2) when two VAWTs are set at a distance of 1.5 to 2.0 times the turbine diameter, the performance of both units increases by about 11% over the efficiency obtainable by their stand-alone counterpart.

Design Criteria on Sizing and Material Selection of SB-VAWTS

2013 ◽  
Author(s):  
Mojtaba Ahmadi-Baloutaki ◽  
Rupp Carriveau ◽  
David S-K. Ting
Keyword(s):  
Wind Turbines ◽  
Material Selection ◽  
Vertical Axis ◽  
Moment Of Inertia ◽  
Power Coefficient ◽  
Design Parameters ◽  
Speed Ratio ◽  
Design Criteria ◽  
Vertical Axis Wind Turbines ◽  
Selection Of

A design methodology has been presented on the sizing and material selection of straight-bladed vertical axis wind turbines. Several design parameters such as turbine power coefficient, blade tip speed ratio, rotor solidity factor, blade aspect ratio and rotor moment of inertia have been analyzed. Material selection and its relevant design criteria have also been discussed for different parts of a straight-bladed vertical axis wind turbines with three blades and two supporting arms per blade. The number of the supporting arms and their optimum locations have been determined via minimizing the bending moments on the blade. A comparative study has also been performed to examine the effect of blade density and turbine H/D ratio on the rotor moment of inertia. It was found that the turbine rotational speed increases as blade density decreases and this increase is larger at higher turbine H/D ratio.

Active Blade Pitch Control for Straight Bladed Darrieus Vertical Axis Wind Turbine of New Design

2013 ◽  
Vol 569-570 ◽  
pp. 668-675 ◽  
Author(s):  
P.D. Chougule ◽  
S.R.K. Nielsen ◽  
Biswajit Basu
Keyword(s):  
Wind Speed ◽  
Wind Turbines ◽  
Pitch Angle ◽  
Vertical Axis ◽  
Power Coefficient ◽  
Vertical Axis Wind Turbine ◽  
Stream Tube ◽  
Pitch Control ◽  
Low Wind Speed ◽  
Blade Pitch Angle

As Development of smallvertical axis wind turbines (VAWT) for urban use is becoming an interestingtopic both within industry and academia. However, there are few new designs ofvertical axis turbines which are customized for building integration. These aregetting importance because they operate at low rotational speed producing veryless noise during operation, although these are less efficient than HorizontalAxis Wind Turbines (HAWT). The efficiency of a VAWT has been significantlyimproved by H-Darrieus VAWT design based on double airfoil technology asdemonstrated by the authors in a previous publication. Further, it is well knowthat the variation of the blade pitch angle during the rotation improves thepower efficiency. A blade pitch variation is implemented by active blade pitchcontrol, which operates as per wind speed and position of the blade withrespect to the rotor. A double multiple stream tube method is used to determinethe performance of the H-Darrieus VAWT. The power coefficient is compared withthat of a fixed pitch and a variable pitch double airfoil blade VAWT. It isdemonstrated that an improvement in power coefficient by 20% is achieved andthe turbine could start at low wind speed

Analysis of Senegal Type Vertical Axis Wind Turbines Arrangement in Wind Farm

2019 ◽  
Vol 13 ◽  
Author(s):  
Li Zheng ◽  
Zhang Wenda ◽  
Han Ruihua ◽  
Qi Weiqiang
Keyword(s):  
Wind Speed ◽  
Flow Field ◽  
Wind Turbine ◽  
Wind Turbines ◽  
Wind Farm ◽  
Wind Farms ◽  
Vertical Axis ◽  
Energy Utilization ◽  
Unit Distance ◽  
Vertical Axis Wind Turbines

Background: In a wind farm, the wind speed of the downstream wind turbine will be lower than the wind speed of the upstream wind turbine due to the influence of the wake. Therefore, the wake of wind turbines is one of the uncertain factors predicting the annual power generation of wind farms. The study of the wake can effectively improve the efficiency of power generation. The arrangement of vertical axis wind turbines in wind farms is rarely studied. Therefore, it is important to study the vertical layout of wind turbines under the influence of wakes to obtain the best layout and unit spacing. Objective: To obtain the optimal layout and unit distance of wind turbines in Senegal wind turbines by studying the arrangement of Senegal vertical axis wind turbines in wind farms. Method: Based on the ANSYS CFX flow field calculation module, the fluid dynamics model of the Senegal fan was established and the flow field simulation analysis was carried out. Based on the Jensen wake model and its improved model, three layout methods for wind farm wind turbines are proposed: two units are arranged in series, two units are arranged in parallel, and three units are staggered. Through the simulation model, the wind energy utilization coefficient and wind speed of the wind turbine in the wind farm are obtained. Results: The optimal separation distance between the units was analyzed from four different angles: wind energy utilization coefficient, torque analysis, downstream tail flow and wind speed cloud contour. Finally, based on the optimal arrangement and unit distance, a triangular staggered wind farm composed of 10 units is established, and the integrated flow field characteristics of the whole wind farm are simulated and analyzed. The integrated flow field wake characteristics of the wind farm are obtained. Conclusion: In all three arrangements, the optimum distance between the units should be three times the diameter of the wind turbine. This arrangement ensures that most of the units are unaffected by the wake, the area affected by the low velocity wake of the wind farm is small, and the area affected by the high speed wake is large.

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