Savonius Turbine Research Articles

Influence of various augmentation devices on the performance characteristics of modified four bladed fixed flip type savonius hydrokinetic turbine

With an intention to improve performance characteristics of the savonius hydrokinetic turbine several modifications were made on the geometrical parameters of the savonius turbine. Though modifications were done on geometrical parameters of savonius turbine but the power coefficient of the savonius turbine didn’t increase compared to the horizontal axis turbines. Augmentation devices are the best alternative to increase the power coefficient of savonius hydrokinetic turbine. Augmentation devices are very effective compared to the other design parameters of savonius hydrokinetic turbine. In this paper, various augmentation devices were used to increase the power coefficient of the modified fixed flip type savonius hydrokinetic turbine. The augmentation devices are used in the present work are, flat deflector, inclined deflector, convergent guide box, convergent–divergent guide box, and Nozzle. The power coefficient was improved with the use of augmentation devices whereas it was very less without augmentation devices. Two deflector with an angle inclination of 45° and 15° has shown maximum power coefficient of 0.54. Modified four bladed fixed flip savonius hydrokinetic turbine without augmentation arrangement shown the, maximum power coefficient of 0.173.

Numerical investigation of vertical axis c-shaped Savonius wind turbine

In recent decades, the use of wind turbines has been successfully increasing in power generation. Various types of wind turbine configurations as well as possible blade geometries are been proposed and are still under development for extracting the maximum possible energy extraction. Vertical axis wind turbine (VAWT) found to have enhanced adaptable physiognomies to the unsteady wind of urban terrains. These turbines can yield electricity from the wind of any direction with low-slung cut-in wind speed. These turbines are ominously quieter than the old-fashioned HAWTs, light-weight, and can be straightforwardly unified into buildings. Hence, the main idea of the present work to numerically evaluate the design performance of a C-shaped Savonius turbine for wind-energy conversion thus obtaining a higher output. During computational fluid dynamic (CFD) simulations, 3 different symmetric and non-symmetric airfoils are examined. After authenticating the numerical procedure against experimental measurements, precise CFD simulations of the unsteady flow around an H-rotor Darrieus turbine have been carried out and presented here. Based on the various configuration of the H-rotor Darrieus turbine tested the DU-06-W-200 found to be capable of wind energy generation, particularly in urban areas.

Design, Development of Aeroleaf of Wind Tree Turbine for Domestic Application

The paper discusses about the wind tree turbine which is a type of vertical axis wind turbine Savonius model. The turbine will be attached to a manufactured tree that will be installed in and around any public area such as parks, roads, public facilities, or business offices. The initial phase discusses about the theoretical evaluation of available wind power for a single aeroleaf wind tree turbine. The second phase evaluates the pressure drop across the aeroleaf blade at the various velocity using CFD simulation. The simulation outcome shows that, pressure drop is directly proportional to the wind velocity which causes rise in the power generated at the shaft. The less pressure drop is produced up to some radius of the aeroleaf and increases as the radius of aeroleaf increased. In third phase of experiment work, design a new single aeroleaf for wind tree turbine to measure actual shaft power at different wind inlet velocity. Experiment performance conducted on a single aeroleaf at different input wind velocities to measure the aeroleaf, entire casing and overall efficiencies. The result shows that power co-efficient increases at beginning and highest reaches at 32% at inlet velocity of 19 m/s.

Effect Of Deflector Angle Into Various Blades Configuration Of Single Stage Vertical Axis Savonius Hydro Turbine Performance

Electrical energy cannot be separated from human life. Today, the exploitation of energy leads to renewable energy. One of the renewable energy is water flow energy. The Savonius turbine is a type of water turbine which is suitable for low flow velocity. One method of increasing the performance of the Savonius Turbine is by using a deflector. This study aims to see the effect of using a deflector on the performance of the Savonius Turbine. The methodology used in this research is testing with variations in the number of turbine blades and deflector angle. The number of turbine blades used were two, three, and four blades, while the deflector angles used were 0°, 20°, 40°, 60°, and 80°. The result show that the using a deflector angle of 80° make turbine inlet flow is better. The best performance is obtained on the three blades Savonius Turbine and 80° deflector angle with power 0.154 Watt and coefficient of power 0.132.

Numerical investigation of conventional and tapered Savonius hydrokinetic turbines for low-velocity hydropower application in an irrigation channel

In the present work, computational fluid dynamics simulation was carried out using ANSYS Fluent to study the performance of conventional and tapered turbine blades for hydrokinetic power generation. The sliding mesh technique is used to study the influence of taper on conventional Savonius turbine using the SST k-ω turbulence model and performance parameters were determined. The geometric parameters used in the present simulation for conventional and tapered turbine blades are aspect ratio and overlap ratio of 1.0 and 0.0. The inlet velocity and depth of water used for present simulation are 0.5 m/s and 103.6 mm for both conventional and tapered turbine blades. The results show that a 5% increase in the performance of a conventional turbine as compare to tapered turbine blade with a taper angle of 5°. The value of maximum coefficient of power for conventional Savonius turbine blade is 0.21 with a tip speed ratio 0.9. The flow field around the conventional and tapered turbine blades at different angular positions are analysed. It was found that there is a loss of energy at the exit side of the advancing blade for the case of tapered turbine, that leads to 5% reduction of performance as compared to the conventional turbine.

Application of Counter Rotating Rotors for Improving Performance of Savonius Turbines

In this paper, a new configuration is proposed for using Savonius rotors by installing two Counter-Rotating Savonius Rotors (CRSR) together. In order to study the aerodynamic performance of the CRSR turbine, 2D unsteady turbulent flow around the CRSR turbine is simulated using commercial CFD software ANSYS-Fluent16.0. Turbulence modeling is done using $$k - \omega$$ SST model. Numerical results demonstrate a considerable improvement in aerodynamic performance of the CRSR turbine in comparison to a single conventional rotor. Effect of the distance between two rotors and different angular positions of two rotors on the CRSR turbine performance is studied. It is shown that the most effective parameter influencing the performance of the CRSR turbine is the distance between the rotors. Numerical results reveal that, locating two rotors in an optimal phase angle (θ = 90) and distance(S = 1.0D0), average power coefficient of the CRSR turbine can be increased to 21%, which indicates a rise of 38% compared to conventional Savonius rotors.

The effects of deflector longitudinal position and height on the power performance of a conventional Savonius turbine

The limited electrical power inherent in rural and remote areas with a narrow width river can be addressed with the utilization of a Savonius hydrokinetic turbine (HKT) that generates electricity from a renewable hydro resource. However, despite its simple design, Savonius HKT practicality is hindered by low power performance. One solution to overcome this issue is to use an augmentation device such as a deflector to improve the performance. However, the effects of deflector geometric parameters on the power performance of such turbine have not been comprehensively studied and information about the flow physics around the turbine with the presence of a deflector are still lacking in literature. Therefore, the present study aims to improve the power performance by varying the advancing blade and the returning blade deflector longitudinal position ratios, ranging from 0.000 to -0.500 and -1.204 to -1.704, respectively, followed by varying the deflector height at 0.5H, 1H and 1.5H of the turbine’s height. Quantitative study has shown that all variations of deflector positions resulted in power performance improvements of more than 30% whereas a reduction by 7.69% was observed for the case with 0.5H deflector. It was found that the optimal deflector longitudinal position ratios were at -0.500 for the advancing blade deflector and -1.204 for the returning blade deflector, whereas the optimal height of deflector was 1H. The qualitative study revealed that the deflector at optimal deflector longitudinal position and height prevented the separated flow from entering the low pressure region between the deflector and the turbine’s blade, reducing unfavorable negative torque on the turbine. Consequently, the turbine exhibited the highest coefficient of power of 0.26 with a significant improvement of 100% relative to without the deflectors.

STUDI EKSPERIMENTAL PERFORMANSI TURBIN SAVONIUS DENGAN PENAMBAHAN PANEL SURYA 100 WP POLYCRISTALLINE DI PESISIR PANTAI KABUPATEN DEMAK TERHADAP DAYA LISTRIK YANG DIHASILKAN

<p><em>The use of fossil fuels in the form of petroleum, coal and natural gas in the long term as conventional power plants causes the scarcity of these fuels in the future. Then the use of new renewable energy such as wind and solar energy must be optimized. In Indonesia, both of these energies have the potential to be environmentally friendly power plants. Experimental research conducted on the coast of Demak Regency aims to determine the potential of wind and solar energy there and the use of both energy as pond lighting. The concept of a combination of solar panels and savonius turbines can produce complementary energy. During the day the battery charging is obtained from a combination of solar panels and savonius turbines while at night the Savonius turbine will still produce electricity. The S-type savonius turbine made from galvalum is mounted on a 6 m tall tower while the 100 WP solar panel is mounted beside it with a 90 slope. This penelitian use expermental methods. Data collection of wind speed, light intensity, electric current, and electric voltage is carried out periodically 20 minutes at 06.20 s.d. 17.20 Western Indonesian Time. Electrical power is obtained by multiplying curr Data analysis in this study uses quantitative descriptive analysisent and voltage. The combination produces enough electricity for lighting a pond in the village of Berahan Kulon, Kecamatan Wedung. The power generated from a combination of hybrid plants can reach 46,2 watts with the intensity of sunlight of 125000 luxmeter and constant wind speed around 2 to 4 m / s. From these results, a combination of turbine savonius and solar panels is more optimal compared to a stand-alone savonius turbine.</em></p>

Effect of number of stages on the performance characteristics of modified Savonius hydrokinetic turbine

Savonius hydrokinetic turbine is considered as an environmentally friendly and cost effective turbine to extract hydrokinetic potential available in flowing streams. However, this turbine has not been fully explored, as the solution for the main problem of low efficiency of Savonius turbine is still being investigated around the globe. In order to study the effect of number of stages, this study aims to analyze the performance of modified Savonius hydrokinetic turbine having twisted blade under different values of number of stages. A commercial unsteady Reynolds-Averaged Navier-Stokes (URANS) solver in conjunction with realizable k-ε turbulence model has been used for the numerical analysis. Pressure and velocity distribution found around the rotor have also been analyzed and discussed. Based on the present investigation, the maximum power coefficient value of 0.44 is obtained for double stage turbine corresponding to tip speed ratio (TSR) value of 0.9 at Reynolds number of 37.53 × 104. Using numerical data obtained, correlation has been developed for power coefficient as a function of number of stages Reynolds number and tip speed ratio.

Design and 3D CFD Static Performance Study of a Two-Blade IceWind Turbine

The IceWind turbine, a new type of Vertical Axis Wind Turbine, was proposed by an Iceland based startup. It is a product that has been featured in few published scientific research studies. This paper investigates the IceWind turbine’s performance numerically. Three-dimensional numerical simulations are conducted for the full scale model using the SST K-ω model at a wind speed of 15.8 m/s. The following results are documented: static torque, velocity distributions and streamlines, and pressure distribution. Comparisons with previous data are established. Additionally, comparisons with the Savonius wind turbine in the same swept area are conducted to determine how efficient the new type of turbine is. The IceWind turbine shows a similar level of performance with slightly higher static torque values. Vortices behind the IceWind turbine are confirmed to be three-dimensional and are larger than those of Savonius turbine.

Experimental Performance Research of Vertical Axis Wind Turbine with Expandable Airfoil

In order to improve the wind energy utilization of the vertical axis wind turbine (VAWT), a new type of VAWT with expandable NACA0012 airfoil is proposed in this paper. The airfoil has opening and folding state. The airfoil is open in windward which is similar with curved blade in Savonius tubine. And it is folded in leeward which is similar with airfoil in H-type turbine. In this paper, a wind tunnel test system is designed to measure the aerodynamic performance of the new turbine and three main structural parameters of the turbine are analyzed. The structural parameters contain the maximum unilateral open angle which influence the flatten of the blade and the sweep wind area. The revolution angle of the rotor corresponding to the self-rotation open angle which influence the effective working time and the airfoil self-rotation effect on the turbine rotation. And the revolution angle of the rotor corresponding to the self-rotation folded angle of the airfoil which influence the wind resistance and impact on the turbine in rapid folding process. The results show that the maximum wind energy utilization of new turbine with appropriate airfoil structural parameters and tip speed ratio corresponding maximum wind energy utilization is higher than Savonius turbine which means the performance of the new turbine capturing wind power is better than Savonius turbine and can be more suitably used in areas with relatively barren wind resource.

Numerical Study of Bach-bladed Savonius Wind Turbine with Varying Blade Shape Factor

Savonius wind turbine with Bach-profile blades is considered in this study. Previous studies have shown that a rotor with the Bach-profile blade produces better performance than a standard Savonius turbine. This study focuses on the blade shape factor variations of the Bach-profile blade to give the best performance. Two-dimensional unsteady simulations are performed with moving mesh. The configuration being tested is the Savonius rotor with Bach-profile blades with an arc angle of 135◦ . The blade shape factor is varied 0.2, 0.3, 0.4 at a constant freestream velocity of 4 m/s, with a corresponding Reynolds number of 20,000. The k-ω Shear Stress Transport turbulence model was used, with secondorder discretization schemes for the pressure and momentum equations. The boundary conditions were set as velocity inlet for the inlet, outflow for the outlet, and walls for the blade surfaces. The top and bottom sides were set as symmetric. Results showed that the configuration with a shape factor of 0.4 gave the best performance among the others. This configuration gave a higher moment coefficient and power coefficient of about 6.8% and 7.3%, respectively. Results extracted from the simulation includes the flow structure, and the distribution of the pressure coefficients along the blade surface.

Performance enhancement of a twisted Savonius hydrokinetic turbine with an upstream deflector

ABSTRACT The conventional Savonius turbine is one of the most used rotors to convert the kinetic energy of natural water resources instead of potential energy. However, this rotor presents low efficiency. A twisted Savonius turbine was appeared which is considered most performant by twisting the blades of the conventional Savonius turbine along theirs spans. In fact, various experimental and numerical investigations were carried out to enhance the efficiency of the twisted Savonius turbine which has not been completely explored. In this study, an experimental investigation was carried out to assess the performance characteristics of a twisted Savonius turbine in an irrigation canal. In order to improve the efficiency of the Savonius turbine, three deflector designs were investigated numerically based on a CFD 3D numerical model. The peak value of the turbine power coefficient reaches 0.166 at a tip-speed ratio value of 0.78 without using a deflector upstream the turbine. Using the deflector design showing the highest efficiency, the peak value of the power coefficient was increased by 17.47%. The use of the proposed deflector is expected to provide toward a more effective employment of flowing water like tidal currents, river streams or other man-made water channels for electrical energy production in rural regions.

The effect of multi-stage modification on the performance of Savonius water turbines under the horizontal axis condition

Abstract Indonesia has the abundant potential of hydropower but not yet processed optimally, which intensely depends on fossil fuel. Hydropower installed in Indonesia is only 11,272 MW, from the estimated potential approximately 94,476 MW. This data shows that 89% of the hydropower potential in Indonesia has not been processed. One of the present efforts to utilize this resource is addressed to develop the Savonius water turbine. Conventional water Savonius turbines have a comprehensible structure and easy to be applied. However, the turbines produce relatively small power, which requires further assessment to improve its performance. The current study is performed by considering geometric changes on the water Savonius turbine to observe their effect on power characteristics. Considered changes are made on the number of stages, and the angle between stages, specifically a single-stage, two-stage 0°, Two-stage 90°, three-stage 0°, and three Stage 120°. The research was carried out by designing simulation model using ANSYS software with CFX Solver. Water speed is determined to 0.8 m/s, while plates with 110 mm in diameter and 110 mm in height are incorporated as rotor configuration. Based on this study, it can be concluded that the addition of the stage affected improving the performance of the Savonius water turbine, where the multi-stage turbine experienced an increment compared to conventional water turbines. The interesting tendency was found on the two-stage rotors with angle of 0° which produced a smaller Cpmax compared to the conventional water Savonius turbines.

On the enhancement of Savonius Bach-type rotor performance by studying the optimum stator configuration

The purpose of the present study is to enhance significantly the Savonius Bach-type rotor performance. This was achieved by adding a new stator around it. The stator is composed of three parts: shield, obstacle, and guide plate. A comprehensive parametric study was performed in which eight geometrical parameters for the stator were varied. One factor at a time method was utilized to find the stator optimum shape that achieves the maximum rotor power coefficient value. A 2D numerical model was employed using ANSYS Fluent 18.1. The dominant parameters that affect the aerodynamic performance of the turbine were demonstrated. According to the examined conditions, the results revealed that the maximum power coefficient for the rotor with optimum stator configuration achieved a value of 6 times greater than that of the bare rotor. It was concluded from this parametric study that the main effective element in the turbine stator is the stator obstacle. This study may be an important issue for further enhancement of the Savonius turbine's performance.

CFD STUDY OF THE EFFECT OF ADDITIONAL INNER BLADES ON SAVONIUS ROTOR PERFORMANCE

The effect of adding inner blades to the Savonius turbine deserves extensive attention due to its promising enhancement to its performance. A numerical study was carried out to investigate the effects of different radii and angles of additional inner blades on the performance of Bach-type rotor at different tip speed ratio (TSR). In the present work, two different studies were performed for a number of cells, domain size and time step. The best numerical model was then used to investigate the effect of the additional inner blades on the Savonius rotor performance. Additional inner blades radii and angles were investigated from 0.25 to 0.85 times original blade radius and 70° to 160° respectively. The best improvement of rotor performance with additional inner blades are higher than values of conventional one by 27.77% at tip speed ratio TSR = 0.75 up to 44.5% at TSR = 0.25.

Numerical Investigations of the Savonius Turbine with Deformable Blades

Savonius wind turbines are characterized by various advantages such as simple design, independence of wind direction, and low noise emission, but they suffer from low efficiency. Numerous investigations were carried out to face this problem. In the present paper, a new idea of the Savonius turbine with a variable geometry of blades is proposed. Its blades, made of elastic material, were continuously deformed during the rotor revolution to increase a positive torque of the advancing blade and to decrease a negative torque of the returning blade. In order to assess the turbine aerodynamic performance, a two-dimensional numerical model was developed. The fluid-structure interaction (FSI) method was applied where blade deformations were defined by computational solid mechanics (CSM) simulations, whereas computational fluid dynamics (CFD) simulations allowed for transient flow prediction. The influence of the deformation magnitude and the position of maximally deformed blades with respect to the incoming wind direction were studied. The aerodynamic performance increased with an increase in the deformation magnitude. The power coefficient exceeded Cp = 0.30 for the eccentricity magnitude of 10% and reached 0.39 for the highest magnitude under study. It corresponded to 90% improvement in comparison to Cp = 0.21 in the case of the fixed-shape Savonius turbine.

Performance Improvement in a Helical Savonius Wind Rotor

Above all vertical axis wind turbines, for their lower cost and independent on wind direction, Savonius rotor takes the advantage to be more suitable for some implementation. Thus, many investigations have been carried out to improve its efficiency. This study emphasizes on the effect of the overlap distance and the blade shape on a helical Savonius wind turbine performance. Assessment methods based on the flow field characterizations, the variation of torque and power coefficient are performed. Thus, transient simulations using the SST k–ω turbulence model are carried out. The numerical model is validated using wind tunnel tests. Results indicate that the non-overlapped helical Savonius rotor highlights higher maximum power coefficient of 0.124 at a tip speed ratio of 0.73 over rotors with overlap distance of 10 mm, 15 mm and 20 mm, respectively. In addition, the delta-bladed rotor improves the performance of the helical Savonius rotor by 14.51%. With the novel blade shape, the maximum power coefficient reaches a value of 0.142 at a tip speed ratio of 0.78. The obtained results present an interesting data that could provide the aerodynamic characteristics of the airflow for the designers and engineers to enhance the efficiency of the helical Savonius turbine.

Experimental investigation of a variable geometry vertical axis wind turbine

An experimental study is presented on the performance of a vertical axis wind turbine with variable blade geometry of the design developed by Austin Farrah. This is experimentally compared with the performance of a correspondingly sized Bach-type Savonius turbine using the same electrical generator and measurement instrumentation in a wind tunnel. Experiments were performed for Reynolds numbers, based on blade chord, in the range 5 × 103to 1 × 105, and for blade settings between −40° and +40o. The study shows that for the tip speed ratios that have been investigated, the Farrah vertical axis wind turbine design can only marginally outperform a corresponding two-bladed Bach-type Savonius turbine and then only when its blades are set to 40° pitch angle. The presence of a small inner cylinder, which rotates with the turbine, does not enhance its performance due to the fact that it is immersed in an extensive column of relatively static air.

Low Speed Vertical Axis Current Turbine (LS-VACT): Experimental Results

Depleting of fossil fuels and climate change problem as well as the pollutions arise make the renewable energy one of the best options for long-term usage. In hydropower energy extraction, vertical axis marine current turbine applications; Savonius turbine, which has the ability to operate in low speed current is suitable with the Malaysia’s sea conditions. However, due to the drawbacks which are low efficiency and low tip speed ratio, modifications need to be done to harness more power. Low Speed Vertical Axis Current Turbine is appeared to extract energy based on the Savonius rotor. In conjunction to this matter, laboratory work has been done in a way to study the relationship between Power Coefficient (Cp) and Tip Speed Ratio (λ), and also the relationship between Torque Coefficient (Ct) and Tip Speed Ratio (λ) at different current speed which are 0.32 m/s and 0.64 m/s.