Numerical Simulation and Virtual Reality Visualization of Horizontal and Vertical Axis Wind Turbines

2011 ◽  
Author(s):  
Nan Yan ◽  
Tyamo Okosun ◽  
Sanjit K. Basak ◽  
Dong Fu ◽  
John Moreland ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Virtual Reality ◽  
Wind Turbine ◽  
Wind Turbines ◽  
Vertical Axis ◽  
Small Scale ◽  
Mechanical Resistance ◽  
Wind Flow ◽  
Horizontal Axis Wind Turbine ◽  
Immersive Environment

Virtual Reality (VR) is a rising technology that creates a computer-generated immersive environment to provide users a realistic experience, through which people who are not analysis experts become able to see numerical simulation results in a context that they can easily understand. VR supports a safe and productive working environment in which users can perceive worlds, which otherwise could be too complex, too dangerous, or impossible or impractical to explore directly, or even not yet in existence. In recent years, VR has been employed to an increasing number of scientific research areas across different disciplines, such as numerical simulation of Computational Fluid Dynamics (CFD) discussed in present study. Wind flow around wind turbines is a complex problem to simulate and understand. Predicting the interaction between wind and turbine blades is complicated by issues such as rotating motion, mechanical resistance from the breaking system, as well as inter-blade and inter-turbine wake effects. The present research uses CFD numerical simulation to predict the motion and wind flow around two types of turbines: 1) a small scale Vertical Axis Wind Turbine (VAWT) and 2) a small scale Horizontal Axis Wind Turbine (HAWT). Results from these simulations have been used to generate virtual reality (VR) visualizations and brought into an immersive environment to attempt to better understand the phenomena involved.

Experimental and Numerical Investigations on Drag and Torque Characteristics of Three-Bladed Savonius Wind Turbine

2009 ◽  
Author(s):  
Mosfequr Rahman ◽  
Khandakar N. Morshed ◽  
Jeffery Lewis ◽  
Mark Fuller
Keyword(s):  
Wind Turbine ◽  
Wind Turbines ◽  
Vertical Axis ◽  
The United States ◽  
Small Scale ◽  
Horizontal Axis Wind Turbine ◽  
Drag Coefficients ◽  
Vertical Axis Wind Turbines ◽  
Torque Coefficient ◽  
Savonius Wind Turbine

With the growing demand of energy worldwide, conventional energy is becoming more and more scarce and expensive. The United States is already facing an energy crunch as the fuel price soars. Therefore, there is an obvious need for alternative sources of energy—perhaps more than ever. Wind is among the most popular and fastest-growing forms of electricity generation in the world, which is pollution free and available almost at any time of the day, especially in the coastal regions. The main attraction of the vertical-axis wind turbine is its manufacturing simplicity compared to that of the horizontal-axis wind turbine. Among all different vertical axis wind turbines, Savonius wind turbine is the simplest one. Operation of the Savonius wind turbine is based on the difference of the drag force on its semi-spherical blades, depending on whether the wind is striking the convex or the concave part of the blades. The advantage of this type of wind turbine is its good self-starting and wind directional independence characteristic. It, however, has a relatively lower efficiency in comparison with the lift type vertical-axis wind turbines. Due to its simple design and low construction cost, Savonius rotors are primarily used for water pumping and wind power on a small scale. The main objective of this ongoing research work is to improve the aerodynamic performance of vertical axis Savonius wind turbine. Wind tunnel investigation has been performed on aerodynamic characteristics, such as drag coefficients, and static torque coefficient of three-bladed Savonius rotor model. Also the computational fluid dynamics (CFD) simulation has been performed using FLUENT software to analyze the static rotor aerodynamics such as drag coefficients and torque coefficient, and these results are compared with the corresponding experimental results for verification.

Development of a High Efficiency and Long Life 500W Class H-Darrieus Type VAWT (Vertical Axis Wind Turbine) System Using Skin-Spar-Foam Sandwich Composite Structure

2012 ◽  
Author(s):  
Changduk Kong ◽  
Haseung Lee
Keyword(s):  
Wind Turbine ◽  
Wind Turbines ◽  
Large Scale ◽  
Performance Test ◽  
High Efficiency ◽  
Vertical Axis ◽  
Small Scale ◽  
Vertical Axis Wind Turbine ◽  
Horizontal Axis Wind Turbine ◽  
Structural Test

Since the energy crisis and the environmental issue have been focused due to excessive fossil fuel consumption, the wind power has been considered as an important renewable energy source. Recently, several MW class large scale wind turbine systems have been developed in some countries. Even though the large scale wind turbine can effectively produce the electrical power, the small scale wind turbines have been continuously developed due some advantages, for instance, it can be easily built by low cost without any limitation of location, i.e. even in city. In case of small scale wind turbines, the vertical axis wind turbine (VAWT) is used in city having frequent wind direction change, even though it has a bit lower efficient than the horizontal axis wind turbine. Furthermore, most small scale wind turbine systems have been designed at the rated wind speed of around 12m/s. This work is to design a high efficiency 500W class composite VAWT blade which is applicable to relatively low speed region. In the aerodynamic design of blade, the parametric studies are carried out to decide an optimal aerodynamic configuration. The aerodynamic efficiency and performance of the designed VAWT is confirmed by the CFD analysis. The structural design is performed by the load case study, the initial sizing using the netting rule and the rule of mixture, the structural analysis using FEM, the fatigue life estimation and the structural test. The prototype blade is manufactured by the hand lay-up and the matched die molding. The experimental structural test results are compared with the FEM analysis results. Finally, to evaluate the prototype VAWT including designed blades, the performance test is performed using a truck to simulate the various range wind speeds and some measuring equipments. According to the performance evaluation result, the estimated performance is well agreed with the experimental test result in all operating ranges.

Adaptive surface distortions for torque ripple control in vertical-axis wind turbines

2019 ◽  
pp. 0309524X1987402 ◽  
Author(s):  
Gareth Erfort ◽  
Theodor W von Backström ◽  
Gerhard Venter
Keyword(s):  
Wind Turbine ◽  
Wind Turbines ◽  
Fluid Dynamic ◽  
Vertical Axis ◽  
Torque Ripple ◽  
Small Scale ◽  
Blade Design ◽  
Vertical Axis Wind Turbine ◽  
Horizontal Axis Wind Turbine ◽  
Vertical Axis Wind Turbines

Vertical-axis wind turbines have been confined to small-scale generation in urban environments where their omnidirectional capability offers them an advantage over the more ubiquitous horizontal-axis wind turbine. With a drive towards renewable energy, more opportunities exist for the implementation of wind turbines in a multitude of environments. Based on its inherent operational drawbacks, the vertical-axis wind turbine has not undergone extensive investigation. Recently, there has been a resurgence of interest in the technology. This article addresses the torque ripple, a variation in torque produced by the turbine, present during operation. The variation in torque generated by a vertical-axis wind turbine increases the likelihood of failure due to fatigue. Current treatment is symptomatic and addresses the result of the torque fluctuation and not the cause. A novel blade design, capable of altering the lift and drag response through shape alteration, is presented as a solution. The blade design and operation is achieved through genetic algorithm optimization and computational fluid dynamic simulations. Comparisons with previous work show the novel blade presented here surpasses the reduction seen with pitching solutions. A 25% reduction in torque ripple was demonstrated for a 17% reduction in performance coefficient using the surface distortion approach. This surpasses the foil pitching approach which achieved a 15% torque ripple reduction for the same loss in performance coefficient.

Aerodynamic Analysis for Camber Effect in Vertical Wind Turbine System

2011 ◽  
Author(s):  
Jinwook Kim ◽  
Dohyung Lee ◽  
Junhee Han ◽  
Sangwoo Kim
Keyword(s):  
Numerical Simulation ◽  
Wind Turbine ◽  
Vertical Axis ◽  
Aerodynamic Characteristics ◽  
Vertical Axis Wind Turbine ◽  
Horizontal Axis Wind Turbine ◽  
Low Wind Speed ◽  
Wind Turbine System ◽  
Physical Features ◽  
The Ideal

The Vertical Axis Wind Turbine (VAWT) has advantages over Horizontal Axis Wind Turbine (HAWT) that it allows less chance to be degraded independent of wind direction and turbine can be operated even at the low wind speed. The objective of this study is to analyze aerodynamics of the VAWT airfoil and investigate the ideal shape of airfoil, more specifically cambers. The analysis of aerodynamic characteristics with various cambers has been performed using numerical simulation with CFD software. As the numerical simulation discloses local physical features around wind turbine, aerodynamic performance such as lift, drag and torque are computed for single airfoil rotation and multiple airfoil rotation cases. Through this study more effective airfoil shape is suggested based vortex-airfoil interaction studies.

Numerical Simulation for the Starting Characteristics of a Wind Turbine

2020 ◽  
Vol 38 ◽  
pp. 215-221
Author(s):  
Anna Kuwana ◽  
Xue Yan Bai ◽  
Dan Yao ◽  
Haruo Kobayashi
Keyword(s):  
Numerical Simulation ◽  
Wind Turbine ◽  
Wind Turbines ◽  
Wind Farms ◽  
Vertical Axis ◽  
Offshore Wind ◽  
Optimum Shape ◽  
Blade Thickness ◽  
Basic Characteristics ◽  
Starting Characteristics

There are many types of wind turbine. Large propeller-type wind turbines are used mainly for large wind farms and offshore wind power generation. Small vertical-axis wind turbines (VAWTs) are often used in distributed energy systems. In previous studies on wind turbines, the basic characteristics such as torque coefficient have often been obtained during rotation, with the turbine rotating at a constant speed. Such studies are necessary for the proper design of wind turbines. However, it is also necessary to conduct research under conditions in which the wind direction and wind speed change over time. Numerical simulation of the starting characteristics is carried out in this study. Based on the flow field around the wind turbine, the force required to rotate the turbine is calculated. The force used to stop the turbine is modeled based on friction in relation to the bearing. Equations for the motion of the turbine are solved by their use as external force. Wind turbine operation from the stationary state to the start of rotation is simulated. Five parameters, namely, blade length, wind turbine radius, overlap, gap, and blade thickness, are changed and the optimum shape is obtained. The simulation results tend to qualitatively agree with the experimental results for steadily rotating wind turbines in terms of two aspects: (1) the optimal shape has an 20% overlap of the turbine radius, and (2) the larger the gap, the lower the efficiency.

scholarly journals Comparison of horizontal axis wind turbine (HAWT) and vertical axis wind turbine (VAWT)

2018 ◽  
Vol 7 (4.13) ◽  
pp. 74 ◽  
Author(s):  
Muhd Khudri Johari ◽  
Muhammad Azim A Jalil ◽  
Mohammad Faizal Mohd Shariff
Keyword(s):  
Wind Turbine ◽  
Wind Turbines ◽  
Vertical Axis ◽  
Green Technology ◽  
Horizontal Axis ◽  
Vertical Axis Wind Turbine ◽  
Horizontal Axis Wind Turbine ◽  
Current Output ◽  
Voltage Output ◽  
And Performance

As the demand for green technology is rising rapidly worldwide, it is important that Malaysian researchers take advantage of Malaysia’s windy climates and areas to initiate more power generation projects using wind. The main objectives of this study are to build a functional wind turbine and to compare the performance of two types of design for wind turbine under different speeds and behaviours of the wind. A three-blade horizontal axis wind turbine (HAWT) and a Darrieus-type vertical axis wind turbine (VAWT) have been designed with CATIA software and constructed using a 3D-printing method. Both wind turbines have undergone series of tests before the voltage and current output from the wind turbines are collected. The result of the test is used to compare the performance of both wind turbines that will imply which design has the best efficiency and performance for Malaysia’s tropical climate. While HAWT can generate higher voltage (up to 8.99 V at one point), it decreases back to 0 V when the wind angle changes. VAWT, however, can generate lower voltage (1.4 V) but changes in the wind angle does not affect its voltage output at all. The analysis has proven that VAWT is significantly more efficient to be built and utilized for Malaysia’s tropical and windy climates. This is also an initiative project to gauge the possibility of building wind turbines, which could be built on the extensive and windy areas surrounding Malaysian airports.  

scholarly journals Numerical Investigations of the Effects of the Rotating Shaft and Optimization of Urban Vertical Axis Wind Turbines

Energies ◽  
2018 ◽  
Vol 11 (7) ◽  
pp. 1870 ◽  
Author(s):  
Lidong Zhang ◽  
Kaiqi Zhu ◽  
Junwei Zhong ◽  
Ling Zhang ◽  
Tieliu Jiang ◽  
...  
Keyword(s):  
Wind Turbine ◽  
Wind Turbines ◽  
Suction Side ◽  
Vertical Axis ◽  
Power Coefficient ◽  
Small Scale ◽  
Physical Parameters ◽  
Rotating Shaft ◽  
Vertical Axis Wind Turbines ◽  
Negative Effect

The central shaft is an important and indispensable part of a small scale urban vertical axis wind turbines (VAWTs). Normally, it is often operated at the same angular velocity as the wind turbine. The shedding vortices released by the rotating shaft have a negative effect on the blades passing the wake of the wind shaft. The objective of this study is to explore the influence of the wake of rotating shaft on the performance of the VAWT under different operational and physical parameters. The results show that when the ratio of the shaft diameter to the wind turbine diameter (α) is 9%, the power loss of the wind turbine in one revolution increases from 0% to 25% relative to that of no-shaft wind turbine (this is a numerical experiment for which the shaft of the VAWT is removed in order to study the interactions between the shaft and blade). When the downstream blades pass through the wake of the shaft, the pressure gradient of the suction side and pressure side is changed, and an adverse effect is also exerted on the lift generation in the blades. In addition, α = 5% is a critical value for the rotating shaft wind turbine (the lift-drag ratio trend of the shaft changes differently). In order to figure out the impacts of four factors; namely, tip speed ratios (TSRs), α, turbulence intensity (TI), and the relative surface roughness value (ks/ds) on the performance of a VAWT system, the Taguchi method is employed in this study. The influence strength order of these factors is featured by TSRs > ks/ds > α > TI. Furthermore, within the range we have analyzed in this study, the optimal power coefficient (Cp) occurred under the condition of TSR = 4, α = 5%, ks/ds = 1 × 10−2, and TI = 8%.

scholarly journals A comparison between the dynamics of horizontal and vertical axis offshore floating wind turbines

2015 ◽  
Vol 373 (2035) ◽  
pp. 20140076 ◽  
Author(s):  
M. Borg ◽  
M. Collu
Keyword(s):  
Wind Turbine ◽  
Wind Turbines ◽  
Vertical Axis ◽  
Static Stability ◽  
Dynamic Responses ◽  
Offshore Wind ◽  
Frequency Range ◽  
Aerodynamic Forces ◽  
Horizontal Axis Wind Turbine ◽  
Support Structure

The need to further exploit offshore wind resources in deeper waters has led to a re-emerging interest in vertical axis wind turbines (VAWTs) for floating foundation applications. However, there has been little effort to systematically compare VAWTs to the more conventional horizontal axis wind turbine (HAWT). This article initiates this comparison based on prime principles, focusing on the turbine aerodynamic forces and their impact on the floating wind turbine static and dynamic responses. VAWTs generate substantially different aerodynamic forces on the support structure, in particular, a potentially lower inclining moment and a substantially higher torque than HAWTs. Considering the static stability requirements, the advantages of a lower inclining moment, a lower wind turbine mass and a lower centre of gravity are illustrated, all of which are exploitable to have a less costly support structure. Floating VAWTs experience increased motion in the frequency range surrounding the turbine [number of blades]×[rotational speed] frequency. For very large VAWTs with slower rotational speeds, this frequency range may significantly overlap with the range of wave excitation forces. Quantitative considerations are undertaken comparing the reference NREL 5 MW HAWT with the NOVA 5 MW VAWT.

Development of a high-efficiency and long-life 500W class H-Darrieus-type vertical axis wind turbine (VAWT) system using skin-spar-foam sandwich composite structure

2013 ◽  
Vol 20 (4) ◽  
pp. 383-394
Author(s):  
Changduk Kong ◽  
Haseung Lee
Keyword(s):  
Wind Turbine ◽  
Large Scale ◽  
High Efficiency ◽  
Vertical Axis ◽  
Small Scale ◽  
Test Results ◽  
Vertical Axis Wind Turbine ◽  
Horizontal Axis Wind Turbine ◽  
Structural Test ◽  
The City

AbstractSince the focus on the energy crisis and environmental issues due to excessive fossil fuel consumption, wind power has been considered as an important renewable energy source. Recently, several megawatt-class large-scale wind turbine systems have been developed in some countries. Even though the large-scale wind turbine can effectively produce electrical power, the small-scale wind turbine has been continuously developed due to some advantages; for instance, it can be easily built at a low cost without any limitation of location, i.e., even in the city. In case of small-scale wind turbines, the vertical axis wind turbine (VAWT) is used in the city despite having a lower efficiency than the horizontal axis wind turbine. Furthermore, most small-scale wind turbine systems have been designed at the rated wind speed of around 12 m/s. This aim of this work is to design a high-efficiency 500W class composite VAWT blade that is applicable to relatively low-speed regions. With regard to the aerodynamic design of the blade, parametric studies are carried out to decide an optimal aerodynamic configuration. The aerodynamic efficiency and performance of the designed VAWT is confirmed by computational fluid dynamics analysis. The structural design is performed by the load case study, initial sizing using the netting rule and the rule of mixture, structural analysis using finite element method (FEM), fatigue life estimation and structural test. The prototype blade is manufactured by hand lay-up and the matched die molding. The experimental structural test results are compared with the FEM analysis results. Finally, to evaluate the prototype VAWT including designed blades, the performance test is performed using a truck to simulate various ranges of wind speeds and some measuring equipment. According to the performance evaluation result, the estimated performance agrees well with the experimental test results in all operating ranges.

scholarly journals Modelo Teórico de los Sistemas de Aerogeneración Eléctrica para las Turbinas Eólicas de Eje Vertical

2019 ◽  
pp. 68-76
Keyword(s):  
Theoretical Model ◽  
Wind Turbine ◽  
Wind Turbines ◽  
Magnetic Induction ◽  
Magnetic Levitation ◽  
Vertical Axis ◽  
Vertical Axis Wind Turbine ◽  
Horizontal Axis Wind Turbine ◽  
Advantages And Disadvantages ◽  
Levitation System

Modelo Teórico de los Sistemas de Aerogeneración Eléctrica para las Turbinas Eólicas de Eje Vertical Theoretical Model of Electric Aerogeneration Systems for Vertical Axis Wind Turbines Anthony Pinedo, Guillermo Ramírez, Lincoln Chiguala, Juan Estrada, David Asmat, Renny Nazario, Daniel Delfín, Lourdes Noriega, Silvia Aguilar, Randy Rosas, Luisa Juárez DOI: https://doi.org/10.33017/RevECIPeru2009.0027/ RESUMEN Existen dos tipos de sistemas de aerogeneración eléctrica por turbinas eólicas, los llamados de eje horizontal (HAWT) y los de eje vertical (VAWT). Ambos proponen ventajas y desventajas, dependiendo de muchos factores. Pero en general, no fue hasta hace unos años que el segundo tipo había sido ignorado, debido a la poca potencia que producía en comparación con los HAWT. Pero con la adaptación de un sistema de levitación, y un nuevo sistema de inducción magnética, las VAWT, lograron incrementar notablemente la energía obtenida, llegando incluso a superar a los HAWT. A pesar que los modelos VAWT han sido harto estudiados en cuanto al esquema experimental y de diseño, no se formuló ninguna explicación sólida, partiendo de principios básicos, sobre el funcionamiento de los VAWT. En este trabajo, se propone un modelo teórico del funcionamiento de los mismos. Para ello, se realizan tres estudios: la interacción del viento con las aspas del aerogenerador, el sistema de levitación magnética y la producción de energía eléctrica por inducción magnética. Estos tres fenómenos, permiten definir y predecir el funcionamiento de tal sistema de aerogeneración. Además, permite «visualizar» la influencia de los diferentes parámetros sobre la eficiencia del sistema, y así pues, poder manejar, los parámetros que controlamos experimentalmente, para obtener una eficiencia óptima. Palabras clave: aerogeneración eléctrica, turbinas de aire, eje vertical, levitación magnética. ABSTRACT There are two types of systems of electric aerogeneration by using wind turbines, one is called horizontal axis wind turbine (HAWT) and the other one is called vertical axis wind turbine (VAWT). Both of them have advantages and disadvantages depending on many factors. Since the second one had produced lees power than the first one, they were ignored. However, the adaptation of a levitation system and a new system of magnetic induction made VAWT increase the power produced and exceed the HAWT. Although VAWT models were studied enough in the design and experimental scheme, there is no solid explanation, based on basic principles, on the operation of the VAWT. In this paper is proposed a theoretical model of VAWT operation. Therefore, three studies are done: the interaction between wind and blades of the turbine, the magnetic levitation system and the energy production by magnetic induction. Those studies make us able to know and predict the operation of those systems. Since, we shall know how many factors are affecting the efficiency of the system; we shall be able to control those parameters in order to get the best efficiency. Keywords: electric aerogeneration, vertical axis wind turbine, magnetic levitation.

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