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Showing papers on "Savonius wind turbine published in 2013"


Journal ArticleDOI
TL;DR: In this article, the performance of a Savonius wind turbine with constant cross-sections is examined by means of quasi 2D flow predictions executed in ANSYS CFX, in a way that allows comparison with wind tunnel data presented in a related paper.

217 citations


Journal ArticleDOI
TL;DR: In this article, a series of wind tunnel investigations on semi-cylindrical three-bladed Savonius rotor scale models with different overlap ratios and without overlap were conducted in front of a low-speed subsonic wind tunnel at different Reynolds numbers.
Abstract: The purpose of this research work is to investigate experimentally and computationally the feasibility of improving the performance of the vertical-axis Savonius wind turbine. The authors first performed a series of wind tunnel investigations on semi-cylindrical three-bladed Savonius rotor scale models with different overlap ratios and without overlap. These experiments were conducted in front of a low-speed subsonic wind tunnel at different Reynolds numbers. Pressures around the concave and convex surfaces of each blade, as well as the static torque for the rotor models, were measured. Using these experimental data, the authors calculated aerodynamic characteristics such as drag coefficients, static torque coefficients, and power coefficients. The authors then performed computational fluid dynamics (CFD) simulations using the commercial CFD software FLUENT and GAMBIT to analyze the static rotor aerodynamics of those models. The experimental and computational results were then compared for verification. Three different models with different overlap ratios were designed and fabricated for the current study to find the effect of overlap ratios. The results from the experimental part of the research show a significant effect of overlap ratio and Reynolds number on the improvement of aerodynamic performance of the Savonius wind turbine. At higher Reynolds number, the turbine model without overlap ratio gives better aerodynamic coefficients, and at lower Reynolds number, the model with moderate overlap ratio gives better results.

52 citations


Journal ArticleDOI
04 Dec 2013-Energies
TL;DR: In this article, a new bucket configuration for a Savonius wind generator is proposed, and numerical analyses are performed to estimate the performances of the proposed configuration by means of the commercial code COMSOL multiphysics® with respect to Savoni wind turbine with overlap only.
Abstract: In this paper a new bucket configuration for a Savonius wind generator is proposed. Numerical analyses are performed to estimate the performances of the proposed configuration by means of the commercial code COMSOL Multiphysics® with respect to Savonius wind turbine with overlap only. Parametric analyses are performed, for a fixed overlap ratio, by varying the slot position; the results show that for slot positioned near the blade root, the Savonius rotor improves performances at low tip speed ratio, evidencing a better starting torque. This circumstance is confirmed by static analyses performed on the slotted blades in order to investigate the starting characteristic of the proposed Savonius wind generator configuration.

36 citations


01 Jan 2013
TL;DR: In this paper, a hybrid vertical axis wind turbine (HWT) is combined with a three bucket H-rotor WT with DUW200 airfoils, and two sets of positions are examined for finding the best case for having the highest performance of the combined WT.
Abstract: In this paper an experimental work is conducted to study the performance of a hybrid vertical axis wind turbine (HWT). A savonius wind turbine (WT) is combined with a three bucket H-rotor WT with DUW200 airfoils. Two sets of positions are examined for finding the best case for having the highest performance of the combined WT. The HWT has been tested in a subsonic wind tunnel in different values of wind velocity. Results show that, in the case that the two turbines (H-rotor and savonius) are combined, higher performance is obtained in compare with H-rotor. Among the two combinations the one that savonius is posed middle of the H-rotor, higher power coefficient is obtained in compare with that of the savonius is below the H-rotor. However, the second position produces more electrical power.

20 citations


Journal Article
TL;DR: In this paper, a Savonius type of vertical axis wind turbine (VAWT) has been designed, fabricated and its performances were tested and a simulate calculation also has been made to expect the power output generated by designed prototype.
Abstract: The wind turbine is a technology which converting wind kinetic energy to electric power. Wind energy is easily accessible anywhere in the world and is one of renewable energy. However, some location such as in Kuala Terengganu, the lower average wind speed become one of the factors wind turbines has not been used widely as an alternative method for generating the electric power. Thereby, small scale wind turbine which can generate electric power in low wind speed must be designed. In this study, a Savonius type of vertical axis wind turbine (VAWT) has been designed, fabricated and its performances were tested. A simulate calculation also has been made to expect the power output generated by designed prototype. From the study, found that although low wind speed, small scale wind turbine still can perform its function and generate electric power. It proves that wind turbines can be as an alternative technology for generating the electric power in Malaysia especially in Kuala Terengganu.

11 citations


Patent
06 Mar 2013
TL;DR: A self-starting wind turbine includes a frame, a rotor assembly that is rotatable about a central axis of rotation and an energy utilizing device operably connected to the rotor assembly.
Abstract: A self-starting Savonius wind turbine includes a frame, a rotor assembly that is rotatable about a central axis of rotation and an energy utilizing device operably connected to the rotor assembly. The rotor assembly has at least two rotors, each rotor having at least two rotor blades. Rotation of the rotor assembly is initiated by wind coming from any direction blowing on any one of the plurality of blades. The rotors are configured in a stacked orientation with the blades fixed at a rotated angular position relative to one another to start rotation of the rotor assembly in variable wind conditions. The rotor assembly is made of a composite laminate and the frame is made of a durable, lightweight material. The frame and the rotor assembly are assembled into a single unit for transportation and utilization.

5 citations


Journal ArticleDOI
TL;DR: In this article, the authors investigated the noise characteristics of wind turbines using CFD techniques and radiated noise was predicted by applying acoustic analogy to the computed flow data, which can be used to design low-noise Savonius wind turbines.
Abstract: Noise performance of small wind turbines is critical since these are generally installed near the community. In this study, flow noise characteristics of Savonius wind turbines are numerically investigated. Flow field around the turbine are computed by solving unsteady RANS equation using CFD techniques and the radiated noise are predicted by applying acoustic analogy to the computed flow data. Parametric study is then carried out to investigate the effects of operating conditions and geometric design factors of the Savonius wind turbine. Tonal noise components with higher harmonic frequency than the BPF are identified in the predicted noise spectra from a Savonius wind turbine. The end-plates and helical blades are shown to reduce overall noise levels. These results can be used to design low-noise Savonius wind turbines.

3 citations


Journal ArticleDOI
TL;DR: In this article, a new approximate stream tube method is developed to predict the momentum, lift, and drag forces on the rotor surfaces by the air stream on the basis of an integral force balance on the turbine blades.
Abstract: This paper develops a new approximate model to predict the pressure and momentum forces on a Savonius-style vertical axis wind turbine. Flow distributions through and around the turbine are examined for analytical predictions of the torque and power output, at all rotor angles. A new approximate streamtube method is developed to predict the momentum, lift, and drag forces on the rotor surfaces by the air stream on the basis of an integral force balance on the turbine blades. Unlike other past analytical methods, the technique predicts both momentum and pressure forces imposed on the rotor surface during operation. The calculated results are validated against experimental data and numerical predictions from computational fluid dynamics. Copyright © 2012 John Wiley & Sons, Ltd.

3 citations


Journal ArticleDOI
TL;DR: In this article, the effect of geometrical configuration on the performance of the Savonius rotor in terms of coefficient of torque, coefficient of power and power output has been investigated, and the results obtained by transient and steady method for the conventional two-bladed rotor are in agreement with those obtained experimentally by other authors.
Abstract: The present study considered the design improvement of Savonius rotor, in order to increase the efficiency of output power. An investigation was conducted to study the effect of geometrical configuration on the performance of the rotor in terms of coefficient of torque, coefficient of power and power output. Modification of conventional geometry has been designed by combining the effect of number of blades and shielding method. CFD simulation was conducted to analyze the flow characteristic and calculate the torque coefficient of all the rotor configurations. The continuity and Reynolds Averaged Navier-Stokes (RANS) equations and realizable k-e epsilon turbulence model are numerically solved by commercial software Ansys-Fluent 14.0. The results obtained by transient and steady method for the conventional two bladed Savonius rotor are in agreement with those obtained experimentally by other authors and this indicates that the methods can be successfully applied for such analysis. The modified 3 and 4 bladed rotors with hybrid shielding method gave the highest maximum power coefficient which 0.37 at TSR 0.5 and output power exceed 4 watts with rotor dimensions of 0.2m width and 0.2m height. This blade configuration also is the best configuration by several percentages compared to the other model from the previous study

2 citations


26 Aug 2013
TL;DR: In this article, unsteady numerical simulations with software Star-CCM+ were conducted to understand clearly the Savonius wind turbine operation, especially by comparing static results (motionless wind turbine) and dynamic results (wind turbine in rotation).
Abstract: In this study unsteady numerical simulations with software Star-CCM+ were conducted to understand clearly the Savonius wind turbine operation, especially by comparing static results (motionless wind turbine) and dynamic results (wind turbine in rotation). This study provides a new vision of its behavior. Indeed, the Savonius is so-called "drag" as its torque is maximum when the blades are perpendicular to the flow direction (maximum projected area). This fact is actually verfyed with a static study. However, the dynamic study shows that the maximum torque is obtained when the axis of the blade is parallel to the wind, so the Savonius wind turbine would be "lift". This study opens new perspectives for the optimization of the Savonius rotors.

2 citations


Proceedings ArticleDOI
01 Jan 2013
TL;DR: In this paper, the interaction between a Savonius wind turbine and a radar by means of simulation using Comsol Multiphysics 4.3a is estimated and compared, and it is shown that the S-shaped wind turbine causes noticeable interference on radar performance, compared to horizontal axis wind turbine.
Abstract: The aim of this paper is to estimate the interaction between a Savonius wind turbine and a radar by means of simulation using Comsol Multiphysics 4.3a. Radar interference depending on each major part of a horizontal axis wind turbine is overviewed and studied. These results are then qualitatively compared with radar interference caused by the S-shaped Savonius wind turbine. It is shown that the S-shaped Savonius wind turbine causes noticeable interference on radar performance, compared to horizontal axis wind turbine.

01 Jan 2013
TL;DR: In this article, a VAWT rotor blade and the gearbox were designed to produce 5 kW of electrical power in the Savonius wind turbine, where the material chosen for the rotor blade was E-glass fiber composite.
Abstract: This project was performed to study and design a VAWT rotor blade and the gearbox to produces 5 kW of electrical power. This project mainly focuses on Savonius wind turbine. The wind speed distribution was observed and the wind energy site was set at Melaka, Malaysia. The relevant design parameters for designing Savonius rotor blade were studied in this report. The Savonius rotor was designed with the rotor diameter of 3.5 m and rotor height of 7 m. The rotor blade thickness was designed as 10 mm. SolidWorks was the design software used in this project. The material chosen for the rotor blade was E-glass fiber composite. Pressure difference between the concave and convex blade surface of Savonius rotor induced to drag force that turn the blade. The pressure difference was obtained by implement Computational Fluid Dynamics (CFD) analysis on SolidWorks Flow Simulation. The two flow types in this project were external flow and internal flow analysis. Both analyses were static analysis. Aerodynamic analysis was performed in manually to obtain the resultant drag force on the rotor blade. The resultant drag force obtained was 595.98 N and this value was used in Finite Element Analysis (FEA) to test the structural reliability. The FEA was performed by SolidWorks Simulation and the result was interpreted in three aspects: stress, deformation and Factor of Safety (FoS). The model with blade thickness of 10 mm was found to be able to withstand the load from wind speed of 7 m/s. The wind turbine gearbox has been designed in three stages which are one stage of planetary gear and two stages of parallel gears. Some theories regarding to the machine element design and structural design have been applied to determine the shaft diameter, number of teeth of the gear, module of the gear, gear ratio and the number gear stages. The wind turbine gearbox has been designed to increase the speed from 60 rpm to 1280 rpm with the gear ratio of 1:21.


01 Jan 2013
TL;DR: In this article, the authors used CFD simulations to validate the design of a wind turbine with a capacity of 50 W and with a wind speed of 5.5 to 6 m/s.
Abstract: Savonius wind turbine is one tool that can convert wind energy into mechanical energy and then be converted into electrical energy. In addition to cheap and simple in its construction, this tool is also easy in perwatannya and suitable for application in areas - rural areas unspoiled by power lines. The method used in this study is a vertical wind turbine design savonius models - U with a capacity of 50 W and using CFD simulations 10.0 as a form of validation of the design of the turbine, and with a wind speed of 5.5 to 6 m / s (data BMG - Jakarta) which is the average wind speed - average in the Greater Jakarta area can be a primary basis of this wind turbine design activities. Based on the results of the calculation of the optimization is done, to the design of wind turbines savonius with power plans 50 W produces torque produced for 3 blades, style torque low 0.85 Nm at a wind speed of 8 m / s to a maximum of 10:46 Nm at a wind speed of 4 m / s , to 5 blade styles torque lows 1:10 Nm at a wind speed of 8 m / s to a maximum of 13.5 Nm at a wind speed of 4 m / s, and for the 6 blade style torque lows 1:20 Nm at a wind speed of 8 m / s and 14.79 Nm at speed wind 4 m / s. By looking at the results from table 4.4 is the result of calculation, and the wind speed data based on the average - average Jabodetabek from BMG - Jakarta of 5.5 - 6 m / s, from turbine design optimization results savonius with variations in wind speed and turbine vast size difference draft obtained power turbine efficiency level of 80% - 90%, due to the efficiency of bearings, gears efficiency and the efficiency of the alternator. Then the optimal design to produce a power of 50 W for local bead is on the design: Torque = 5:24 Nm, V = 6 m / s, B = 6 pieces, Cp = 0:18, d = 1.61 m, r = 1.61 m, wide catchment rotor = 2.09 m2 and a height = 1.3 m rotor. And of the validation process CFD generated torque = 5.30 Nm.

Journal Article
TL;DR: In this paper, a two-dimensional model carried out the simulation of the flow pattern, velocities and pressures of airflow within a Savonius wind rotor placed in smoke wind tunnel.
Abstract: Vertical axis wind turbine (VAWT) type Savonius rotor is self-starting, inexpensive, less technicality & high productivity wind machine, which can accept wind from any direction without orientation, and provides high starting torque. The investigations of aerodynamic parameters and the flow pattern of the turbulent flow through the rotor have high aspect on Savonius wind turbine performance. The flow pattern through a three buckets Savonius rotor model of 10cm diameter inside smoke wind tunnel with high-speed camera was investigated experimentally. The commercial code FLUENT 6.3.26 used to simulate the turbulent flow (M 2000) by RNG K-e turbulent model. Two-dimensional model carried out the simulation of the flow pattern, velocities and pressures of airflow within a Savonius wind rotor placed in Smoke wind tunnel. The domain of the airflow dived for two zone, first zone up and down stream flow meshed by fixed structured grid generation. The second zone is around Savonius rotor; the flow pattern created by a pitched blade rotor was calculated by using a sliding mesh technique with unstructured grid generation. Three time steps between two blades of rotor is taken, which give three angular orientations of blades. The CFD results show good agree with experimental results of flow pattern. It is concluded that the sliding mesh method is suitable for the prediction of flow patterns around wind turbine. Then after ensured from the reliability of CFD simulation, it can be used for studying the velocity contour and the pressure distribution around the turbine.


01 Jan 2013
TL;DR: In this article, the authors proposed a hybrid concept combining solar cell panels and Savonius turbine to gain a greater electrical output than the solar cells panels and wind turbine that operate in their own task.
Abstract: ABSTRAK The use of fossil energy for conventional power plants in the long time will run out of oil, gas and coal reservoir. Therefore the renewable energy utilization that more environmentally friendly and renewable concepts such as wind and solar heat should be optimized. Two kind of potential renewable energy resources in Indonesia that should be optimized are wind power and solar energies. They will be complement each other, in the dry season the sun will be role while in the rainy season wind power will be more dominant. This hybrid concept combining solar cell panels and Savonius turbine to gain a greater electrical output than the solar cell panels and Savonius wind turbine that operate in their owntask. A Single stage Savonius wind turbines are made three design types to find the best design that can convert more energy from any wind direction. A solar cell panel is placed under the sun to produce current and voltage from sun light. The energy summation data will be recorded by Data Aquisition System. From The measurement and data analysis results, the electrical power generated by prototype of hybrid system is 7,5 watt. This value is greater if compare to the power generated by solar panels and