scholarly journals Effect of Stator Vane on the Performance of the Savonius Wind Turbine

2019 ◽  
Vol 4 (2) ◽  
pp. 159-168
Author(s):  
Yoga Arob Wicaksono
Keyword(s):  
Wind Turbine ◽  
Performance Testing ◽  
Turbine Rotor ◽  
Power Coefficient ◽  
Speed Ratio ◽  
Stator Vane ◽  
Torque Coefficient ◽  
Savonius Wind Turbine ◽  
Air Speed ◽  
Turbulent Air Flow

The turbulent air flow conditions in the urban area have a large effect on the performance of Savonius rotor wind turbines. To overcome this problem, a new design of the stator vane needs to be made. the stator vane has the ability to direct wind to the turbine rotor and increase air speed by utilizing throttling effects. Thus, the performance of the Savonius wind turbine can increase. In this study, the Savonius type vertical wind turbine is configured with three stator vane designs that have slope angles: 60o, and 70o. Performance testing is carried out at angles: 0o, 30o, and 60o towards the midpoint of the stator vane to find the direction of direction coming from the best wind on each stator vane design. All configurations are analyzed using an experimental wind tunnel open testing scheme with a wind speed range of 3-5 m/s. The parameters produced from the experiment include: power coefficient (Cp), torque coefficient (Ct) and Tip Speed ​​Ratio (TSR). The results showed that the stator vane with 60o inclination angle was able to increase Cp 35.66% in the 60o incoming wind direction.

Optimization of Two and Three Rotor Savonius Wind Turbine

2015 ◽  
Author(s):  
Ahmed M. Baz ◽  
Nabil A. Mahmoud ◽  
Ashraf M. Hamed ◽  
Khaled M. Youssef
Keyword(s):  
Wind Turbine ◽  
Average Power ◽  
Power Coefficient ◽  
Speed Ratio ◽  
Rotor Design ◽  
Aerodynamic Interaction ◽  
Torque Coefficient ◽  
Savonius Wind Turbine ◽  
Improved Performance ◽  
Turbine Design

The present work investigates the performance of Savonius wind turbine using two or three rotors. The new turbine design was found to have higher power coefficient compared with single rotor design. The peak average power coefficient of the three rotors was computed to be 50% higher than that of the single rotor design. The torque coefficient was also higher than that of the single rotor turbine at high tip speed ratio. This improved performance is attributed to the favorable aerodynamic interaction between the rotors which accelerates the flow around the rotors and generates higher turning torque in the direction of rotation for each rotor. The optimized arrangement of rotors showed that the upstream rotor and one downstream rotor should have a similar direction of rotation while the second downstream rotor is rotating in opposite direction.

scholarly journals Performance assessment and optimization of a helical Savonius wind turbine by modifying the Bach’s section

2021 ◽  
Vol 3 (8) ◽  
Author(s):  
M. Niyat Zadeh ◽  
M. Pourfallah ◽  
S. Safari Sabet ◽  
M. Gholinia ◽  
S. Mouloodi ◽  
...  
Keyword(s):  
Wind Turbine ◽  
Performance Assessment ◽  
Turbulent Flows ◽  
Power Coefficient ◽  
Speed Ratio ◽  
Tip Speed Ratio ◽  
Basic Model ◽  
Turbine Performance ◽  
Primary Model ◽  
Savonius Wind Turbine

AbstractIn this paper, we attempted to measure the effect of Bach’s section, which presents a high-power coefficient in the standard Savonius model, on the performance of the helical Savonius wind turbine, by observing the parameters affecting turbine performance. Assessment methods based on the tip speed ratio, torque variation, flow field characterizations, and the power coefficient are performed. The present issue was stimulated using the turbulence model SST (k- ω) at 6, 8, and 10 m/s wind flow velocities via COMSOL software. Numerical simulation was validated employing previous articles. Outputs demonstrate that Bach-primary and Bach-developed wind turbine models have less flow separation at the spoke-end than the simple helical Savonius model, ultimately improving wind turbines’ total performance and reducing spoke-dynamic loads. Compared with the basic model, the Bach-developed model shows an 18.3% performance improvement in the maximum power coefficient. Bach’s primary model also offers a 12.4% increase in power production than the initial model’s best performance. Furthermore, the results indicate that changing the geometric parameters of the Bach model at high velocities (in turbulent flows) does not significantly affect improving performance.

Development of a Scaled Rotor Blade for Tank Tests of Floating Wind Turbine Systems

2018 ◽  
Author(s):  
Paul Schünemann ◽  
Timo Zwisele ◽  
Frank Adam ◽  
Uwe Ritschel
Keyword(s):  
Wind Turbine ◽  
Rotor Blade ◽  
Turbine Rotor ◽  
Full Scale ◽  
Power Coefficient ◽  
Speed Ratio ◽  
Model Scale ◽  
Floating Wind Turbine ◽  
Hydrodynamic Effects ◽  
Wind Turbine Rotor

Floating wind turbine systems will play an important role for a sustainable energy supply in the future. The dynamic behavior of such systems is governed by strong couplings of aerodynamic, structural mechanic and hydrodynamic effects. To examine these effects scaled tank tests are an inevitable part of the design process of floating wind turbine systems. Normally Froude scaling is used in tank tests. However, using Froude scaling also for the wind turbine rotor will lead to wrong aerodynamic loads compared to the full-scale turbine. Therefore the paper provides a detailed description of designing a modified scaled rotor blade mitigating this problem. Thereby a focus is set on preserving the tip speed ratio of the full scale turbine, keeping the thrust force behavior of the full scale rotor also in model scale and additionally maintaining the power coefficient between full scale and model scale. This is achieved by completely redesigning the original blade using a different airfoil. All steps of this redesign process are explained using the example of the generic DOWEC 6MW wind turbine. Calculations of aerodynamic coefficients are done with the software tools XFoil and AirfoilPrep and the resulting thrust and power coefficients are obtained by running several simulations with the software AeroDyn.

Four Decades of Research Into the Augmentation Techniques of Savonius Wind Turbine Rotor

2018 ◽  
Vol 140 (5) ◽  
Author(s):  
Nur Alom ◽  
Ujjwal K. Saha
Keyword(s):  
Wind Turbine ◽  
Turbine Rotor ◽  
Power Coefficient ◽  
Major Drawback ◽  
High Rotational Speed ◽  
Savonius Rotor ◽  
Augmentation Techniques ◽  
Savonius Wind Turbine ◽  
Low Efficiency ◽  
Wind Turbine Rotor

The design and development of wind turbines is increasing throughout the world to offer electricity without paying much to the global warming. The Savonius wind turbine rotor, or simply the Savonius rotor, is a drag-based device that has a relatively low efficiency. A high negative torque produced by the returning blade is a major drawback of this rotor. Despite having a low efficiency, its design simplicity, low cost, easy installation, good starting ability, relatively low operating speed, and independency to wind direction are its main rewards. With the goal of improving its power coefficient (CP), a considerable amount of investigation has been reported in the past few decades, where various design modifications are made by altering the influencing parameters. Concurrently, various augmentation techniques have also been used to improve the rotor performance. Such augmenters reduce the negative torque and improve the self-starting capability while maintaining a high rotational speed of the rotor. The CP of the conventional Savonius rotors lie in the range of 0.12–0.18, however, with the use of augmenters, it can reach up to 0.52 with added design complexity. This paper attempts to give an overview of the various augmentation techniques used in Savonius rotor over the last four decades. Some of the key findings with the use of these techniques have been addressed and makes an attempt to highlight the future direction of research.

scholarly journals STUDI EKSPERIMENTAL PERFORMANSI TURBIN SAVONIUS DI PESISIR PANTAI KABUPATEN DEMAK TERHADAP DAYA LISTRIK YANG DIHASILKAN

2021 ◽  
Vol 14 (1) ◽  
pp. 16
Author(s):  
Wahyu Santoso ◽  
Herman Saputro ◽  
Husin Bugis
Keyword(s):  
Renewable Energy ◽  
Wind Speed ◽  
Wind Energy ◽  
Wind Turbine ◽  
Raw Material ◽  
Power Coefficient ◽  
Speed Ratio ◽  
Generator Type ◽  
Wind Potential ◽  
Savonius Wind Turbine

<p><em>Energy from fossil fuels consisting of petroleum, coal, natural gas containing raw material for energy fulfillment in Indonesia is still very central through the use of raw materials from renewable energy is still very low. In Indonesia the potential for renewable energy such as wind energy needs to be optimized. One of the uses of wind energy is through savonius wind turbine as electricity generators. Characteristics of savonius wind turbine with vertical axis rotors which gave a simple shape, and that able to control low speeds. This is in accordance with regions in Indonesi which have low average speeds.         This experimental study, aims to determine the description of wind potential and determine the performance of savonius wind turbines on the coast of Demak regency on the electrical energy produced. Savonius wind turbine used is made of galvalum material in the form of an S type rotor with diameter 1.1 m and height 1.4 m, using pulley transmission system with multiplication ratio 1:6 dan using generator type PMG 200 W. This research uses the method experiment. Data collection in the form of wind speed, humidity, temperature, rotor rotation speed, voltage and electric curret is carried out at 14.30 to 17.30 Western Indonesian Time. Data Analysis in this study uses quantitative descriptive analysis. The result showed the potential of wind on the coast of Demak regency have an average wind speed of 2,02 m/s with a temperature of 31</em><em>,</em><em>34 </em><em><sup>0</sup></em><em>C and humidity of 76,96. And the performance of the installed wind turbine produces the highest power 3.5 watt with an electric power coefficient of 0,181 and tip speed ratio around 1,75. From these result, the potensial of wind with performance savonius turbine can generate electricity used for pond lighting in the village Berahan Kulon Kecamatan Wedung. </em><em></em></p>

scholarly journals Comparative Numerical Analysis on Vertical Wind Turbine Rotor Pattern of Bach and Benesh Type

Energies ◽  
2020 ◽  
Vol 13 (9) ◽  
pp. 2311 ◽  
Author(s):  
Fanel Dorel Scheaua
Keyword(s):  
Numerical Analysis ◽  
Classical Model ◽  
3D Models ◽  
Turbine Rotor ◽  
Point Of View ◽  
Power Coefficient ◽  
Speed Ratio ◽  
Ansys Cfx ◽  
Torque Coefficient ◽  
Bladed Rotor

In this work, 3D models in classic configuration of Bach and Benesh rotor type, as well as models with modified blade pattern geometry were analyzed from the air circulation point of view inside the rotor enclosure in order to identify the operating parameters differences according to rotor geometric modified configuration. Constructive design aspects are presented, as well as results obtained from the virtual model analysis in terms of circulation velocity and pressure values which enhance rotor operation related to torque and power coefficients. The rotors design pattern is made according to previous results obtained by different researchers who have performed numerical analysis on virtual models and tests on the experimental rotor models using the wind tunnel. The constructive solutions are describing two-bladed rotor models, in four new designed constructive variants and analyzed using ANSYS CFX. The air velocity specific values, static and total pressure recorded at the rotor blade level are highlighted, that influence the obtaining of rotor shaft torque and power. Also torque coefficient (CT) and power coefficient (CP) values according with specific values of tip speed ratio (TSR) are presented for each analyzed case. The analysis results show higher power coefficient values for analyzed Bach V2 and Benesh V2 rotor modified models compared to the classic Bach and Benesh models for 0.3 TSR of 0.11–012 CP, 0.4 TSR of 0.18 CP (Benesh V2 model) and 0.27 CP at 0.6 TSR (Bach V2). The resulted values confirm that Benesh V2 model offers higher CP up to 5% at TSR 0.3, 2% at TSR 0.6 and 3% at TSR 0.4 compared to the Benesh classical model. The Bach V2 model offers 4% higher CP compared to the classic Bach model at TSR 0.6. Based on these results it is intended the further analytical and experimental research in order to obtain optimal rotor pattern.

Experimental Study of a Pinwheel-Type Wind Turbine

2003 ◽  
Vol 27 (3) ◽  
pp. 227-236 ◽  
Author(s):  
Yasuyuki Nemoto ◽  
Izumi Ushiyama
Keyword(s):  
Experimental Study ◽  
Wind Tunnel ◽  
Wind Turbine ◽  
Optimum Design ◽  
Architectural Design ◽  
Frontal Area ◽  
Power Coefficient ◽  
Speed Ratio ◽  
Tip Speed Ratio ◽  
Torque Coefficient

Pinwheels have been familiar as toys for hundreds of years. Not only do they have an attractive appearance, they can also be fabricated from just one piece of plate. Application is possible, e.g. for education and architectural design. The purpose of this paper is to clarify the characteristics and to determine the optimum design configuration of pinwheel type wind turbines. The authors fabricated the test rotors with various shapes and carried out the experiment in a wind tunnel. As a result, the following facts were obtained: (1) Power coefficient with the traditional 4 blades has, CPmax = 0.17 at λ = 2. (2) High tip speed is obtained by cutting the frontal area of pinwheel. Tip speed ratio at no load can be easily changed from λ = 3 to 6 by changing the cutting area. Maximum power coefficient CPmax = 0.22 was obtained at tip speed ratio λ = 3.5. (3) Increased torque is obtained by cutting the edge area of the pinwheel. Tip speed ratio at no load can be easily changed from λ = 2 to 3, and torque coefficient can be easily changed from CQmax = 0.15 to 0.25, by changing the cut area.

Strategic Blade Shape Optimization for Aerodynamic Performance Improvement of Wind Turbines

2016 ◽  
Author(s):  
Youjin Kim ◽  
Ali Al-Abadi ◽  
Antonio Delgado
Keyword(s):  
Wind Turbine ◽  
Wind Turbines ◽  
Optimization Methods ◽  
Turbine Rotor ◽  
Aerodynamic Performance ◽  
Power Coefficient ◽  
Speed Ratio ◽  
Blade Shape ◽  
Improved Design ◽  
Wind Turbine Rotor

This study introduces strategic methods for improving the aerodynamic performance of wind turbines. It was completed by combining different optimization methods for each part of the wind turbine rotor. The chord length and pitch angle are optimized by a torque-matched method (TMASO), whereas the airfoil shape is optimized by the genetic algorithm (GA). The TMASO is implemented to produce an improved design of a reference turbine (NREL UAE Phase V). The GA is operated to generate a novel airfoil design that is evaluated by automatic interfacing for the highest gliding ratio (GR). The adopted method produces an optimized wind turbine with an 11% increase of power coefficient (Cp) with 30% less of the corresponding tip speed ratio (TSR). Furthermore, the optimized wind turbine shows reduced tip loss effect.

scholarly journals Drag coefficient calculation of modified Myring-Savonius wind turbine with numerical simulations

2020 ◽  
Vol 10 (2) ◽  
pp. 73-84
Author(s):  
Mahmoud Saleh ◽  
Endre Kovács
Keyword(s):  
Drag Coefficient ◽  
Wind Turbine ◽  
Primary Objective ◽  
Power Coefficient ◽  
Speed Ratio ◽  
Energy Potential ◽  
Cross Sectional ◽  
Ansys Fluent ◽  
Tip Speed Ratio ◽  
Savonius Wind Turbine

Nowadays the importance of renewable energy is growing, and the utilization of the low wind energy potential is getting crucial. There are turbines with low and high tip speed ratio. Turbines with low tip speed ratio such as the Savonius wind turbine can generate adequate amount of torque at low wind velocities. These types of turbines are also called drag machines. The geometry of the blade can greatly influence the efficiency of the device. With Computational Fluid Dynamics (CFD) method, several optimizations can be done before the production. In our paper the Savonius wind turbine blade geometry was designed based on the so-called Myring equation. The primary objective of this paper was to investigate the drag coefficient of the force acting on the surface of the blade. Also, the Karman vortex was investigated and the space ratio of that vortex in our simulation was compared to a typical one. The power coefficient of a new Savonius turbine was investigated at different values of top speed ratio (TSR). For the sake of simplicity, a 2D cross-sectional area was investigated in the simulation with ANSYS Fluent 19.2.

scholarly journals Numerical Model Analysis of Myring–Savonius wind turbines

2019 ◽  
Vol 4 (1) ◽  
pp. 180-185
Author(s):  
M. Saleh ◽  
Ferenc Szodrai
Keyword(s):  
Wind Turbine ◽  
Turbine Blade ◽  
Primary Objective ◽  
Power Coefficient ◽  
Speed Ratio ◽  
Energy Potential ◽  
Cross Sectional ◽  
Tip Speed Ratio ◽  
Savonius Wind Turbine ◽  
Cfd Method

Nowadays the importance of renewable energy is growing, and the utilization of the low wind energy potential is getting crucial. There are turbines with low and high tip speed ratio. Turbines with low tip speed ratio such as the Savonius wind turbine can generate adequate amount of torque at low wind velocities. These types of turbines are also called drag machines. The geometry of the blade can greatly influence the efficiency of the device. With Computational Fluid Dynamics (CFD) method, several optimizations can be done before the production. In our paper the Savonius wind turbine blade geometry was based on the so-called Myring equation. The primary objective of this paper was to increase the power coefficient by modelling the effect of the wind on the turbine blade. For the sake of simplicity, a 2D cross-sectional area was investigated in the simulation with ANSYS CFX 19.1.

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