On the performance analysis of Savonius rotor with twisted blades
TL;DR: In this paper, a three-bladed rotor system has been tested in a low speed wind tunnel, and its performance has been compared with conventional semicircular blades (with twist angle of 0°) on the basis of starting characteristics, static torque and rotational speed.
About: This article is published in Renewable Energy.The article was published on 2006-09-01. It has received 248 citations till now. The article focuses on the topics: Rotor (electric) & Savonius wind turbine.
Citations
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TL;DR: In this paper, the performance, blade design, control and manufacturing of horizontal axis and vertical axis wind turbines are reviewed based on experimental and numerical studies and lessons learnt from various studies/countries on actual installation of small wind turbines were presented.
Abstract: Meeting future world energy needs while addressing climatic changes has led to greater strain on conventional power sources. One of the viable sustainable energy sources is wind. But the installation large scale wind farms has a potential impact on the climatic conditions, hence a decentralized small scale wind turbines is a sustainable option. This paper presents review of on different types of small scale wind turbines i.e., horizontal axis and vertical axis wind turbines. The performance, blade design, control and manufacturing of horizontal axis wind turbines were reviewed. Vertical axis wind turbines were categorized based on experimental and numerical studies. Also, the positioning of wind turbines and aero-acoustic aspects were presented. Additionally, lessons learnt from various studies/countries on actual installation of small wind turbines were presented.
383 citations
TL;DR: In this paper, the authors present a review on the performance of Savonius wind turbines and present relevant information about their performance, bringing a discussion about the performance and benefits of using this type of turbines.
Abstract: This paper presents a review on the performance of Savonius wind turbines. This type of turbine is unusual and its application for obtaining useful energy from air stream is an alternative to the use of conventional wind turbines. Simple construction, high start up and full operation moment, wind acceptance from any direction, low noise and angular velocity in operation, reducing wear on moving parts, are some advantages of using this type of machine. Over the years, numerous adaptations for this device were proposed. The variety of possible configurations of the rotor is another advantage in using such machine. Each different arrangement of Savonius rotor affects its performance. Savonius rotor performance is affected by operational conditions, geometric and air flow parameters. The range of reported values for maximum averaged power coefficient includes values around 0.05–0.30 for most settings. Performance gains of up to 50% for tip speed ratio of maximum averaged power coefficient are also reported with the use of stators. Present article aims to gather relevant information about Savonius turbines, bringing a discussion about their performance. It is intended to provide useful knowledge for future studies.
337 citations
TL;DR: In this article, wind tunnel tests were conducted to assess the aerodynamic performance of single-, two-and three-stage Savonius rotor systems with both semicircular and twisted blades.
337 citations
TL;DR: In this article, the geometry of the blade shape (skeleton line) was optimized in the presence of the obstacle plate to increase the output power of a Savonius turbine.
263 citations
TL;DR: In this paper, a helical Savonius rotor with a twist of 90° was proposed to decrease the variation in static torque from 0° to 360°, and the performance of the helical rotor with and without shaft was compared in an open jet wind tunnel.
258 citations
References
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TL;DR: In this article, a Savonius rotor wind turbine was tested in the Vought Corporation Systems Division 4.9- x 6.1m Low Speed Wind Tunnel to determine aerodynamic performance.
Abstract: Fifteen configurations of a Savonius rotor wind turbine were tested in the Vought Corporation Systems Division 4.9- x 6.1-m Low Speed Wind Tunnel to determine aerodynamic performance. The range of values of the varied parameters was as follows: number of buckets, 2 and 3; nominal freestream velocity, 7 and 14 m/s; Reynolds number per meter, 4.32 x 10/sup 5/ and 8.67 x 10/sup 5/; rotor height, 1 and 1.5 m; rotor diameter (nominal), 1 m; bucket overlap, 0.0 to 0.1 m. The measured test variables were torque, rotational speed, and tunnel conditions. It is concluded that increasing Reynolds number and/or aspect ratio improves performance. The recommended configuration consists of two sets of two-bucket rotors, rotated 90 deg apart, with each rotor having a dimensionless gap width of 0.1 to 0.15.
381 citations
TL;DR: In this paper, a wind tunnel test was made on a number of Savonius rotor configurations in wind speeds of 6-9 m/s with variable variables including blade aspect ratio, blade overlap and gap and the effects of adding end extensions, end plates and shielding.
199 citations
Book•
01 Jan 1997
TL;DR: In this paper, wind turbine theory and application wind energy resources aerodynamics components and operational characteristics are discussed, and project assessment and engineering economic assessment planning authorization, environmental and social issues applications project engineering national and international wind energy programmes.
Abstract: Part 1 - Wind turbine theory and application wind energy resources aerodynamics components and operational characteristics. Part 2 - project assessment and engineering economic assessment planning authorization, environmental and social issues applications project engineering national and international wind energy programmes.
177 citations
"On the performance analysis of Savo..." refers background in this paper
...[2 7 ] w it h o u t d efl ec to r 1 9 8 6 S -s h a p ed 0 ....
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...Savonius rotor has a high starting torque and a reasonable peak power output per given rotor size, weight and cost, thereby making it less efficient [5]; the coefficient of performance is of the order of 15% [6,7]....
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...H o lo w n ia [1 7 ] 1 9 7 8 S a v o n iu s 0 ....
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TL;DR: In this paper, an extensive wind tunnel test program is described which assesses the relative influence of system parameters on the Savonius rotor performance, and a semi-empirical approach to predict the rotor performance using measured stationary blade pressure data is developed.
Abstract: An extensive wind tunnel test program is described which assesses the relative influence of system parameters on the Savonius rotor performance. The parametric study leads to an optimum configuration with an increase in efficiency by around 100 percent compared to the reported efficiency of approx. 12-15 percent. Of particular interest is the blockage correction procedure which is vital for application of the wind tunnel results to a prototype design, and facilitates comparison of data obtained by other investigators. Next, using the concept of a central vortex, substantiated by a flow visualization study, a semiempirical approach to predict the rotor performance using measured stationary blade pressure data is developed. The simple approach promises to be quite effective in predicting the rotor performance, even in the presence of blockage, and should prove useful at least in the preliminary design stages.
146 citations
"On the performance analysis of Savo..." refers background or methods in this paper
...Modi and Fernando [18] have described a mathematical model based on the discrete vortex method to predict the performance of a stationary and a rototary Savonius configuration....
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...Blade configurations were studied in wind tunnels to evaluate the effect of aspect ratio, blades overlap and gap, effect of adding end extensions, end plates and shielding [8,10,16–18]....
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TL;DR: In this article, the aerodynamic performance of a Savonius rotor has been studied by measuring the pressure distributions on the blade surfaces at various rotor angles and tip-speed ratios, and it is found that the pressure distribution on the rotating rotor differ remarkably from those on the still rotor especially on the convex side of the advancing blade, where a low pressure region is formed by the moving wall effect of the blade.
Abstract: The aerodynamic performance of a Savonius rotor has been studied by measuring the pressure distributions on the blade surfaces at various rotor angles and tip-speed ratios. It is found that the pressure distributions on the rotating rotor differ remarkably from those on the still rotor especially on the convex side of the advancing blade, where a low pressure region is formed by the moving wall effect of the blade. The torque and power performances, evaluated by integrating the pressure, are in close agreement with those by the direct torque measurement. The drag and side force performance is also studied.
89 citations
"On the performance analysis of Savo..." refers methods in this paper
...The aerodynamic performance was also studied by Fujisaw and Gotoh [19] from the blade surface pressure distributions at various rotor angles and tip-speed ratios....
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