Investigating a Modified Vertical Axis Wind Turbine (original) (raw)
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Aerodynamic Performance of Vertical-Axis Wind Turbines
Journal of Marine Science and Engineering
The nonstationary separated incompressible flows around Darrieus and Savonius rotors of vertical-axis wind turbines were investigated through computational simulation using the Reynolds averaged Navier–Stokes equations and Spalart–Allmaras turbulence model. The implicit finite-volume algorithm, the basis of which was artificial compressibility method, was chosen to obtain the numerical solution. The series of computational and physical experiments for Darrieus rotors with varied numbers and shapes of blades were performed. The detailed visualization of the flow was presented. The turbulent flows surrounding the Darrieus and Savonius rotors were studied, and as a part of these investigations, the major phases of vortex progress were identified. For this purpose, three series of computer tests on the aerodynamic and power properties of Savonius rotors with two and three buckets were performed, and their results are also presented. The influence of tip-speed ratio, solidity, and Reynol...
Simulation Study on the Performance of Vertical Axis Wind Turbine
Applied Mechanics and Materials, 2013
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-ε 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...
E3S Web of Conferences, 2021
In this study, the researcher applied an experimental method to examine the performance of theSavonius-type turbine, in which variations in the blade angle were 85°, 95°, 105°, 110°, 115°, and 125°, variations in wind speed were 3 and 4.1 m/s, and variations in balancing force were 0.4 and 0.9 kg. The results showed that, of the five examined variations of the blade angle, the 125° blade produced the highest rotation (n) compared to the others. It generated 115.3 rpm but without a balanced force. Furthermore, the turbine performance at a wind speed (V) of 4.1 m/s, a balancing force (F) of 0.9 kg, and a blade angle of 125° produced the rotational speed (n) of 69.6 rpm, the turbine power (Pt) of 6.43 watts, the torque (T) of 1.765 N.m, the tip-speed ratio (λ) of 0.355, and the turbine efficiency 66.22%. Meanwhile, at a wind speed of 3 m/s, a balancing force (F) of 0.9 kg, and a blade angle of 125°, it generated the rotational speed (n) of 28.6 rpm, the turbine power (Pt) of 2.64 watts...
Review Paper of Savonius Vertical Axis Wind Turbine Rotor Blade
This paper involves study of Savonius Vertical Axis Wind Turbine (SVAWT) blades. In past few years more research works are carried out to increase efficiency of Vertical Axis Wind Turbine. Review of all these papers shows that the experiments are conducted only on semi cylindrical bucket shape blades, twisted blades, blades with end flap edges and blades having frames with cavity vanes, for two blades, three blades and four bladed Savonius Vertical Axis Wind Turbine(SVAWT) to increase performance. They also conducted experiments by providing curtains or flow guide to the rotor, increasing in the stages of rotor and combining both Savonius and Darrieus rotor (i.e. hybrid rotors) to increase the efficiency of rotor. Research work or experiments on semi cylindrical bucket rotor blade edges, having extrusion or leading edges with different angles are not carried out. Development of these designs includes a multidisciplinary design optimization approach for optimizing the Vertical Axis Wind Turbine blade, considering both structural and fluid flow performance requirements. Weighted Property Method, Cost Property Method, limits Property Methods are used for Selection of suitable material. ANSYS and Computational Fluid Dynamics are used for structural analysis and fluid flow performance of newly designed blade.
2019
The main objective of this paper is to increase the low performance of the unconventional Savonius vertical-axis wind rotor turbine. Three configurations (model 1, 2 and 3) of Savonius rotor were designed for the selected arc bucket angles of 60°, 75° and 90°. The effect of bucket angles on the rotor performance was analyzed both experimentally and numerically. The rotor performance was obtained through the static torque for each model. The static torque at different rotor angles ranging from 0 to 180 was studied at various wind speeds of 4, 6 and 8 m/s. The experimental investigations on unconventional Savonius rotors were conducted in an open wind tunnel. Numerical models used are the software SolidWorks Flow Simulation (SWFS) and Trigonometric Fourier Series (TFS). By comparing the numerical and experimental results it can be concluded that the rotor of arc bucket angle of 90° gives the best performance at higher wind speed than the other two models for all rotor angles. Moreover...
CFD Letters
Small-scale wind turbines are considered recently as an attractive source of renewable energy, especially at remote area with respect to city centre. The design and characterization of a small vertical wind turbine are introduced through this work. A CFD analysis has been used as a first step in design to simulate the flow around the vertical blades of the small wind turbine. Different parameters have been taken into account in this work such as blades number, shape, and existence of stator blades deflector. Three different versions depend on blade profile have been examined. The turbulence model with sliding mesh in CFD have been performed. In this paper, a performance of small-scale of vertical wind turbine represented by CFD results of power coefficient, and optimal freestream velocity of this model are presented. The results showed that using 8 blades of VAWT instead of 4 blades with the same profile of blade has enhanced VAWT performance up to 64%. Also, increasing the concave ...
Review of Specific Performance Parameters of Vertical Wind Turbine Rotors Based on the SAVONIUS Type
Energies
Increasing energy demand and environmental regulations around the world provide an adequate framework for developing methods of obtaining energy from renewable sources. Wind force is a resource with a high potential through which green energy can be obtained with no negative impact on the environment. Different turbine typologies have been developed, which can convert the wind force into mechanical and electrical energy through turbine rotational motion. Starting from the classic vertical-axis SAVONIUS rotor model, other models have been designed, which, according to the numerical studies and experimental test results, show higher performance parameters in operation. Such models present specific rotor blade geometries to achieve better operational results in terms of shaft torque and generated power. There are multiple research results from numerical analysis on virtual models or experimental tests that use rotor models in different constructive configurations aiming to improve oper...
Study of the bucket design effect on the turbulent flow around unconventional Savonius wind rotors
Energy, 2015
In this paper, computer simulation has been conducted to study the aerodynamic structure around an unconventional Savonius wind rotor with a 75° bucket arc angle. The numerical model is based on the resolution of the Navier-Stokes equations in conjunction with the standard k-ε turbulence model. These equations were solved by a finite volume discretization method. The software "Solidworks Flow simulation" has been used to characterise the flow characteristics in different transverse and longitudinal planes. The good comparison between numerical and experimental results confirms the validity of the numerical method.
2018
Due to the importance and advantages of Vertical-axis wind turbines (VAWTs) over traditional horizontal-axis wind turbines (HAWTs), this paper is implemented. Savonius turbines with drag-based rotors are adopted from the two more extensive arrangements of vertical wind turbines because of their advantages. In this paper, six diverse rotor plans with measure up to cleared regions are analyzed with exploratory wind burrow testing and numerical reenactments. These proposed models incorporate a conventional Savonius with two different edges criteria and 90 degree helical bend models with two, three and four sharp edges. The models were designed using SolidWorks software then the physical models were 3D printed for testing. A subsonic open-sort wind burrow was utilized for Revolution per Minute (RPM) and torque estimation over a scope of wind speeds. ANSYS Fluent reenactments were utilized for dissecting streamlined execution by using moving reference outline and sliding lattice display ...
Review on Aerodynamic Performance Evaluation of Straight Blade Vertical Axis Wind Turbine.pdf
As the energy crisis is getting severe in the world it will be important to investigate alternative methods of generating power in ways different than, fossil fuels. In fact, one of the biggest sources of energy is all around us all of the time, the wind. Currently, horizontal axis wind turbines (HAWT) dominate the wind energy market due to their large size and high power generation characteristics. However, vertical axis wind turbines (VAWT) are capable of producing a lot of power, and offer many advantages for small-scale and domestic applications. One drawback of DARRIEUS type VAWT is their inability to reliably selfstart at low tip speed ratio. The details of different configurations and performance evaluation techniques along with the major findings of researchers on vertical axis wind turbines are reviewed in this paper. The main purpose of the study described here is to investigate effect of different design parameter on performance evaluation of VAWT.