Effect of Conventional Multistage Savonius wind Turbines on the Performance of the Turbine at Low Wind Velocity (original) (raw)
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An Experimental Study on the Performance of Savonius Wind Turbines Related With The Number Of Blades
Energy Procedia, 2015
Wind energy is the most abundantly available clean form of renewable energy in the earth crust. Wind turbines produce electricity by using the power of wind to drive an electric generator. There are two kinds of wind turbines according to the axis of rotation to the ground, horizontal axis wind turbines (HAWT) and vertical axis wind turbines (VAWT). VAWTs include both a drag type configuration like Savonius wind turbine and a lift-type configuration like Darrieus wind turbine. Savonius wind rotor has many advantages over others in that its construction is simpler and cheaper. It is independent of the wind direction and has a good starting torque at lower wind speeds. The experimental study conducted in this paper aims to investigate the effect of number of blades on the performance of the model of Savonius type wind turbine. The experiments used to compare 2, 3, and 4 blades wind turbines to show tip speed ratio, torque and power coefficient related with wind speed. A simulation using ANSYS 13.0 software will show pressure distribution of wind turbine. The results of study showed that number of blades influence the performance of wind turbine. Savonius model with three blades has the best performance at high tip speed ratio. The highest tip speed ratio is 0.555 for wind speed of 7 m/s.
Influence of Design Parameters on the Performance of Savonius Wind Turbine
International Journal of Innovative Science and Research Technology, 2022
In this era of technological advancement, the demand for energy requirements is increasing globally. With a limited stock of fossil fuels and the pollution issue related to the burning of these fuels, the world needs to find an alternative of it, which must be cleaner and greener. This is where wind energy comes in and plays a vital role as it is a clean source and has a very promising future in the global energy sector. Savonius turbine is a type of vertical axis wind turbine (VAWT) which is predominantly rotated by the drag force from the wind. It is self starting and can extract wind energy from low wind speeds and is very practical to install it in crowded places due to its compact geometry. This thesis is a review of the previous works presented by different authors. This project aims at discovering the influence of various design and performance parameters (aspect ratio, overlap ratio, tip speed ratio, blade shape, number of rotor blades and number of stages), turbulence models and turbine geometries on the performance of Savonius vertical axis wind turbine. A conventional Savonius vertical axis wind turbine (VAWT) with aspect ratio of 1, overlap ratio of 0.15 and TSR of 0.8 shows the maximum coefficient of power (CP) The performance of conventional rotors can be enhanced by use of helical rotors; multi-staging and other modified blade geometries. Helical rotors with blade twist angle of 90 0 are better performing rotors than the conventional rotors. Modified Bach type rotor with a blade arc angle of 135 0 , aspect ratio of 1.1, overlap ratio of 0.1 and at tip speed ratio (TSR)= 0.8 show the maximum coefficient of power (CP) of 0.30. The results of numerical analyses were compared with that of the experimental data and it is found that for 2-D numerical analyses, realizable k-ɛ turbulence model shows better accuracy of estimation and for 3-D analyses, SST kω turbulence model shows better agreement with the experimental data.
Study on performance of a savonius wind turbines related with the blade angle
Maejo International Journal of Energy and Environmental Communication, 2019
This research aimed to compare the performance of Savonius vertical axis wind turbines through blade numbers and different blade angles. In this study, applicable turbines having 4, 6, 8, 12, 16 and 18 numbers of blades with the angles of the blades of -15°, -5°, 0°, 5° and 15°, respectively. The rotor used was a semicircle shaped blade made from PVC material and has a blade diameter of 6 cm and 30 cm for both rotor diameter and height. The turbine was tested deadweight range of 0-0.49 kg at 4 m/s wind speed. The results showed that the blade angle has a positive effect on increasing the power and torque coefficient of Savonius wind turbine, specifically on blades less than 16. The highest power and torque coefficient was obtained from the turbine having16 blades at an angle of 5°. This configuration also found that the maximum power and torque coefficient in the tip speed ratio ranging from 0.3-0.4 are 0.2519 and 0.5858, respectively.
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...
Energies
Small-scale vertical-axis wind power generation technologies such as Savonius wind turbines are gaining popularity in suburban and urban settings. Although vertical-axis wind turbines (VAWTs) may not be as efficient as their horizontal-axis counterparts, they often present better opportunities for integration within building structures. The main issue stems from the suboptimal aerodynamic design of Savonius turbine blades, resulting in lower efficiency and power output. To address this, modern turbine designs focus on optimizing various geometric aspects of the turbine to improve aerodynamic performance, efficiency, and overall effectiveness. This study developed a unique optimization method, incorporating a new blade geometry with guide gap flow for Savonius wind turbine blade design. The aerodynamic characteristics of the Savonius wind turbine blade were extensively analyzed using 3D ANSYS CFX software. The optimization process emphasized the power coefficient as the objective fun...
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...
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 ...
Design of Savonius vertical axis wind turbine for low speed wind field
THE 6TH INTERNATIONAL CONFERENCE ON SCIENCE AND TECHNOLOGY (ICST21): Challenges and Opportunities for Innovation Research on Science Materials, and Technology in the Covid-19 Era
Wind was a potential renewable energy source in Indonesia. The basis for the utilization of wind energy was in the design of the turbine. Savonius vertical axis wind turbine can be used for low-speed and unstable winds in residential areas. Analytical solutions can be used for the optimization of wind turbine structural design. The parameters of the horizontal and vertical sections of the turbine greatly affect the performance of the turbine. The optimization of the structure in the horizontal section is carried out by modifying the overlap ratio and modifying the blade curvature. Based on the literature, the optimum overlap ratio of a turbine with two blades was 0.15. In addition, the use of turbine blades with a semicircle design can improve turbine performance. Optimization of the structure in the vertical section was done by tappering the blades to reduce the initial torque value of the turbine. This analytical approach resulted in a Savonius wind turbine design that theoretically satisfies the working conditions in residential areas.
International Journal of Energy and Environmental Engineering, 2013
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.
Study of a Savonius Type Wind Turbines for its Aerodynamic Characteristics
The primary objective of this paper is to conduct a comparative study on the number of blade and different blade angles of a domestic savonius vertical axis wind turbine with semicircular shaped blades under a range of wind speeds. A domestic scale 6bladed Savonius Vertical Axis Wind Turbine was manufactured to investigate the effect of blade number and blade angle on the maximum power generation by the turbine. Maximum power curves as a function of wind speeds were established for each configuration. The results show that the blade angle has positive effect to increase the power output of a Savonius turbine to a significant amount. The most efficient configuration is the 6bladed turbine with an angle of attack of 10°. This configuration generated 27% more power compared to the 0° angle of attack at the wind speed from 10 to 15 km/h.