Savonius Wind Turbine Research Articles

ANALISIS PERFORMA TURBIN ANGIN VAWT (VERTICAL AXIS WIND TURBINE) TIPE HYBRID SAVONIUS DARRIEUS NACA 4712

A wind turbine is a device that converts wind energy into mechanical energy to produce electric power. Wind turbines have a simple working principle, which is to convert wind energy into mechanical energy in the windmill, then the rotation of the turbine0makes the rotor on the generator rotate and generate electricity. There are 2 types of wind turbines: vertical axis wind turbine and horizontal axis wind turbine. This study aims to determine the performance of the medium-scale VAWT hybrid savonius darrieus NACA 4712 wind turbine. The hybrid wind turbine is a combination of savonius and darrieus wind turbines to increase efficiency by utilizing the drag of the savonius turbine and lift force from the darrieus wind turbine. This study used an experimental method. The fan is used to vary the wind speed. The wind speed used ranges from 5, 5.5, 6, 6.5, 7, 7.1,7.2,7.3 m/s. This savonius darrieus hybrid wind turbine can produce efficiency of 0.037 at wind speed of 5 m/s with an initial torque of 0.088 N/m. The maximum rotation in this hybrid turbine study 118 Rpm was obtained at a wind speed of 7.3 m/s.

PERANCANGAN TURBIN ANGIN SAVONIUS UNTUK SISTEM PENERANGAN DENGAN STRIP LED PADA JEMBATAN

Today the availability of energy sources in the future is a global problem that continues to be the concern of all countries in the world. Electrical energy is one of the most basic needs in a country, especially in Indonesia. In addition to the problem of the need for electrical energy, lighting in the bridge area is also still a polemic to this day. Based on the studies that have been carried out, it is necessary to maximize the utilization of renewable energy sources, one of which is wind energy as a supplier of electrical energy by applying the concept of a wind power plant (PLTB). Based on the problems that have been described, a creative and innovative idea was initiated to help lighting on bridges in an effort to reduce the number of traffic accidents with the design title Savonius wind turbines for lighting systems with LED strips on bridges.

Aerodynamic Characteristics of a Square Cylinder with Vertical-Axis Wind Turbines at Corners

A preliminary study is carried out to investigate the aerodynamic characteristics of a square cylinder with Savonius wind turbines and to explain the reason why this kind of structure can suppress wind-induced vibrations. A series of computational fluid dynamics simulations are performed for the square cylinders with stationary and rotating wind turbines at the cylinder corners. The turbine orientation and the turbine rotation speed are two key factors that affect aerodynamic characteristics of the cylinder for the stationary and rotating turbine cases, respectively. The numerical simulation results show that the presence of either the stationary or rotating wind turbines has a significant effect on wind forces acting on the square cylinder. For the stationary wind turbine cases, the mean drag and fluctuating lift coefficients decrease by 37.7% and 90.7%, respectively, when the turbine orientation angle is 45°. For the rotating wind turbine cases, the mean drag and fluctuating lift coefficients decrease by 34.2% and 86.0%, respectively, when the rotation speed is 0.2 times of vortex shedding frequency. Wind turbines installed at the corners of the square cylinder not only enhance structural safety but also exploit wind energy simultaneously.

Modified Savonius Wind Turbine for Wind Energy Harvesting in Urban Environments

Abstract The flow-induced rotation of the modified Savonius rotor, for which the blade consists of a semicircular profile and an elliptical shape, is studied using a series of unsteady computational fluid dynamics (CFD) simulations. This study first concentrates on the validation of the numerical scheme against Blackwell's experimental data of the conventional rotor. The computed flow physics around the modified rotor with the same diameter is then analyzed and compared with that of the conventional rotor during one rotation cycle. As the result, the modified rotor is outperforming the conventional one but keeping its unique features. The modified rotor offers exceeding performance at a tip speed ratio (TSR) greater than 0.8. The new peak of the power coefficient Cp is reached at TSR = 1.4 which is a typical operating condition of the wind turbine in urban areas. The remarkable finding is that the suppression of the flow separation on the blade is an effective way to improve the rotor's aerodynamic performance. As expected, the additional elliptical profile plays a key role in increasing the positive torque and in preventing the flow separation on the blade, especially at high TSR > 0.8. Finally, this study points to not only advances the fundamental understanding of flow mechanism around the rotor but also proposes a good practical energy harvesting application in urban environments.

Savonius Wind Turbine Numerical Parametric Analysis Using Space-Filling Design and Gaussian Stochastic Process

Wind energy is an alternative source of clean energy to address the growing energy demand and provide pollution-free electricity. With the rapid development of urban areas, high wind energy resources such as high-rise building rooftops are excellent locations for urban wind turbine installation. One of the practical and simple urban wind turbines is the Savonius design. It has a simple design, easy to maintain, and is very affordable. This work focuses on the design evaluation of a Savonius wind turbine (SWT) by varying the rotor diameter, rotor height, and twist angle for urban applications. A transient computational fluid dynamics (CFD) approach is applied to assess the various design treatments using a space-filling design of experiments. To address the spaces in the hypercube statistical design, a sphere packing design method was adopted which suited the evaluation of computational simulations results such as that of the CFD. The Gaussian stochastic process model was applied to establish the trend of the parametric performance of the optimized SWT design through the model fitting. The results have shown that optimized SWT performs well with its self-starting capability compared to the traditional Savonius design. In addition, the optimized SWT has shown a better peak power coefficient compared with the results of previous works on the design of SWT.

Investigating the effects of wind concentrator on power performance improvement of crossflow wind turbine

Small wind turbines are efficient for solving power supply problems in remote off-grid regions. A crossflow wind turbine is a drag-based small vertical axis wind turbine, which is suitable for small-scale power generation in the built environment because of its low aerodynamic noise. However, the power performance of a crossflow wind turbine is generally lower than that of a Savonius wind turbine. Aiming at improving the performance of a crossflow wind turbine, this study develops a wind concentrator by adding two parallel plates with flanges, which is based on the “wind lens” concept, to an arc-shaped windshield, which is based on an existing concept of a flow deflection device for a crossflow wind turbine. The effects of adding two parallel plates with flanges to the windshield (i.e., the effects of the wind concentrator) on the performance of the crossflow wind turbine are quantified with wind tunnel experiments and analyzed based on the flow field characteristics obtained by computational fluid dynamics simulations. The experimental results show that the wind concentrator enhances the maximum power coefficient of the crossflow wind turbine by 108% from 0.12 (without wind concentrator/windshield) to 0.25 (with the wind concentrator), whereas the arc-shaped windshield improves it by 48% from 0.12 to 0.17 (with the windshield). The numerical simulations reveal that the main cause for the power performance enhancement is a downward deflection of the approaching flow to the upper part of the rotor because of a significant increase in the pressure level on the upwind side of the upper flange and an overall decrease in the pressure level in the wake of the wind concentrator. In conclusion, adding two parallel plates with flanges to an arc-shaped windshield is effective for significantly enhancing the power performance of a crossflow wind turbine.

Feasibility study of twin-rotor Savonius wind turbine incorporated with a wind-lens

Sustainability and more power generation are vast crucial issues in the commercialization of vertical axis wind turbines specifically for small-scale and urban applications. Savonius rotors are an attractive kind of turbine compared to other wind turbines due to their simple design and self-starting capability. However, these types of turbines have low performance in terms of power generation. This study employs a wind accelerator called “wind-lens” for Savonius wind turbine in single-rotor and twin-rotor configurations to harness more viable energy even in the low-speed region. The results of the present study can help designers and scientists to interpret the effective parameters of the proposed system for further development. High-fidelity numerical simulations are performed to investigate operational parameters like tip speed ratio and geometric parameters such as the rotational direction and position of the rotors within the wind-lens. Also, using the pressure and velocity contours along with the streamlines, an attempt is made to describe the power improvement by the proposed system. The results show that a twin-rotor ducted turbine in the optimal point can improve the maximum power coefficient of the system by about 114% relative to an open turbine.

Effect of the variations of the gap flow guides geometry on the savonius wind turbine performance: 2D and 3D studies

The Savonius wind turbine has been identified to have low power and torque coefficients. Numerous blade shapes and modifications have been proposed to improve its performance. In the present study, double gap flow guides of different lengths of 25–100 mm were introduced at different angular positions of 45–90° in a 0.5 m diameter blade Savonius turbine. The unsteady Reynolds Averaged Navier Stokes equations and the turbulence equations corresponding to SST k−ω were solved using the commercial software ANSYS FLUENT. Simulations were conducted in 2D and validated with 3D simulations at key points. The extracted results of the coefficient of performance and torque were compared with the available experimental data for the purpose of validation. A maximum increase of 12.24% in the coefficient of performance was observed for model 75 (degree angle) - 75 (mm length) at a tip speed ratio 1. Despite the high performance of model 75-75, model 60–75 showed a higher average of coefficient of performance across the considered range of tip speed ratios. The advantage of gap flow guides was explained in light of streamline plots, velocity vector plots and pressure distribution curves.

Optimal design and sensitivity analysis of airfoil-shaped rotor blade for Savonius wind turbine by using response surface methodology

The Savonius wind turbine is cost-effective, simple in structure, and potentially usable in urban areas but suffers from poor efficiency. Further, vortices emerges downward results in a higher rate of exergy loss and lower wind energy to power conversion rate. Thus, the objective of the present study is to enhance the performance of the Savonius wind turbine and reduction of generated friction entropy considering the novel design of airfoil-shaped blade. For this purpose, nine important design parameters of airfoil-shaped blade were chosen and dozen design points were designed based on the Plackett-burman method. After carrying out the screening analysis, the response surface methodology has been used to conduct sensitivity analysis and investigate the higher-order correlations to discover the optimal design of studied airfoil-shaped blade. The obtained results indicate that the optimal design could augment the power coefficient up to 12.89% at TSR = 0.8, compared to conventional semicircular rotor blade.

Effect of flexible blades on the Savonius wind turbine performance

Effect of flexible blades on the Savonius wind turbine performance

A simulation investigation the performance of a small scale Elliptical Savonius wind turbine with twisting blades and sloping ends plates

Savonius wind turbine is among of simplest type of vertical axis wind turbines to produce the power from wind. Elliptical blades one of adopted geometry to design the Savonius turbine rotor. One of the most important measures to improve the performance of elliptical Savonius turbine rotor by developing the blade geometry. In this study, a CFD simulation used to investigate the effect of geometrical parameters of the small scale elliptical Savonius turbine rotor (ESTR) with inner surface wavy blades. The simulation has been implemented in a in a two configurations design models, ESTR models with twisting angle in range of (5˚ to 45˚) and ESTR models with tilt angle of end plates (3˚ to 15˚) with a constant Aspect ratio of 1 and overlap ration of 0.2. The performance evaluation were in terms of power coefficient and torque coefficient as a function of tip speed ratio. The numerical results show that an increase in the maximum power coefficient with increase of twist angle and tilt angle until optimum values of 30˚ and 12˚ for the twist angle and tilt angle, respectively. Although in all configuration show a good increase in power coefficient but there are a significant increasing in maximum power coefficient for ESTR model with twist angle of 30˚ which was 3.7% while the increasing reach to 14.55% at ESTR model with tilt angle 12˚ at tip speed ratio of 7. As well as, these two models provide a jump in power coefficient for a different range of tip speed ratio compare to previous model of ESTR.

Performance Improvement in Savonius Wind Turbine by Modification of Blade Shape

Wind energy is one of the abundantly available renewable energy resources. Savonius vertical axis wind turbine is better suited for small scale power generation applications with many advantages. The turbine operates independent of wind direction with good starting torque and less noise. But, the power coefficient of the Savonius turbine is less than all other wind turbines. The shape of the turbine blades plays an important role in the performance of the turbine. In this present two-dimensional numerical study, an attempt has been made to improve the turbine performance by considering three types of blade shapes. The complete design details of the proposed new blade shapes are presented. The simulations are carried out using ANSYS Fluent 15.0 with SST K-ω turbulence model. The power coefficient of the modified blade is found to have increased by 20% compared to conventional blade shape. The effect of tip-speed-ratio on power coefficient has also been studied and reported.

Efficiency enhancement of a hybrid Vertical axis wind turbine by utilizing Optimum parameters

The present study suggests a conflation of the redesigned Savonius and Darrieus (airfoil S-1046) Vertical Axis Wind Turbine (VAWT) to examine its efficiency. The hybrid version of VAWT was specifically proposed to imbricate the drawbacks of individual turbines, such as the substandard autorotation capability of the Darrieus turbine, high negative torque, and low efficiency of the Savonius turbine. The pressure-based fluent solver has been implemented along with second-order upwind equations. The SST k-ω turbulence model is utilized, with an incoming wind velocity of 9 m/s. To demonstrate the turbine's performance, comprehensive comparisons of torque (C m ) and power (C p ) were performed at Tip Speed Ratios (TSR) ranging from 1 to 1.4. The current rotor overcomes the subpar autorotation capability of the conventional Darrieus rotor by attaining a maximum C m of 0.21 at TSR 1.4. Further, it breaks the diminishing trend in efficiency with an increase in TSR compared to the conventional drag force-based rotor. In comparison to the conventional hybrid rotor, the present study enhances the C p by 5.66% and 8.39% at TSRs of 1.3 and 1.4, respectively.

Experimental study on improving the performance of the Savonius wind turbine with ailerons (Improvement of wind turbine effective in low tip speed ratio)

Experimental study on improving the performance of the Savonius wind turbine with ailerons (Improvement of wind turbine effective in low tip speed ratio)

Measurement and analysis for the improvement of efficiency and power of Savonius vertical axis wind turbines without dimples and fins

Energy effective approaches to improve the extraction of work from different sources of renewable energy are still appreciated in this energy starved world. Wind energy is one such widely used source. Wind energy is one of the world's most rapidly expanding electricity industries and most exciting alternative energy sources. A. Crespo, J. Hernandez, and S. Frandsen, “Survey of modelling methods for wind turbine wakes and wind farms Wind turbine technology is a method for converting wind kinetic energy into electrical energy. Efforts have been made in recent years to increase the capacity and reliability of standard Savonius VAWTs, which are not only easy to create but can also be used as a renewable energy source to meet the needs of rural areas with low power consumption. A.J. Alexander, B.P. Holownia Wind tunnel tests on a Savonius rotor; Journal of Industrial Aerodynamics In this present research paper, we analysis for the improvement of Efficiency and the power of the Savonius type wind turbine without using dimples on their blades and fins for more pressure generation Akwa, J. V., Vielmo et al., Review on the Performance of Savonius Wind Turbines“, Renewable and Sustainable Energy. the Savonius vertical axis wind turbine could be a safer alternative because it can also work in low wind conditions The aim of this model is to demonstrate its performance in varying wind conditions as opposed to the conventional horizontal axis wind turbine, and to contribute to its steady increasing popularity as a reliable source of power generation in the near future.

Examination of the Effect of Triangular Plate on the Performances of Reverse Rotating Dual Savonius Wind Turbines

Examination of the Effect of Triangular Plate on the Performances of Reverse Rotating Dual Savonius Wind Turbines

Optimization of the Power Coefficient of a Savonius Wind Turbine by Changing the Shape of Blades

Optimization of the Power Coefficient of a Savonius Wind Turbine by Changing the Shape of Blades

Aerodynamic performance enhancement of a Savonius wind turbine using an axisymmetric deflector

The installation of wind turbines in urban sites requires consideration of the wind characteristics affecting the energy production (turbulence, environment roughness due to the surrounding buildings …), the self-starting capability and the type, hence the performance, of the wind turbine. In this paper, a three-dimensional CFD analysis of an aerodynamic Savonius wind turbine is performed under steady wind conditions. The inclusion of a deflector was also investigated, and the performance compared to the initial design.Results of the 3D analysis showed that an optimized axisymmetric deflector improves the power coefficient in all wind directions and over the entire operating range of the turbine. The deflector also increased the average starting torque by 30%, thus extending the operating range of the turbine with respect to the wind speed.

Aeroacoustics behavioral study of Savonius wind turbine

Vertical Axis Wind Turbines (VAWTs) are appropriate for use in populated areas. If VAWTs were installed at residential areas, the generated aerodynamic noise can be harmful in a way or another. Therefore, in the present study, the aero-acoustics of the conventional Savonius Wind turbine was investigated using Computational Fluid Dynamics (CFD). Both the Unsteady Reynolds-averaged Navier-Stokes (URANS) equations and impermeable Ffowcs Wiliams and Hawkings (FW-H) equation were simultaneously solved. The effect of speed ratio was also studied. The results indicate that; the pressure is inversely proportional to the speed ratio. Additionally, the velocity has been increased due to the increase of the tip speed ratio. Finally, it has improved that for the majority of receivers, the overall sound level increases with increasing speed ratio.

Design, experimental and feasibility study for highway electricity generation using low‐cost wind turbine

With the ever-increasing demand for electricity, the need to generate electricity from potential sources is high. A promising idea to generate electricity from highways is proposed, designed and tested. A low cost Savonius wind turbine (SWT) was fabricated at a cost of around $110 and was tested by placing in highways at varying wind speed and traffic conditions to generate electricity. This generated electricity is utilized to satisfy the electricity needs of the rural houses nearby highways with rural electrification schemes to operate lighting. From the experimental data, the estimated average electricity generation from a SWT was found around 0.4 kWh/day. The life cycle analysis (LCA) of the proposed system is conducted by considering the real-time economic parameters. Also, the economic study conducted showed the levelized cost of electricity was around $0.07/kWh LCA is studied by considering as a SWT farm installed with 250 SWTs connected in 1 km stretch with estimated power output around 100 kWh/day. With this, the demand for energy for atleast 6 h/day in rural households is fulfilled.