Academic literature on the topic 'VAWT (vertical axis wind turbine)'
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Journal articles on the topic "VAWT (vertical axis wind turbine)"
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Khudri Johari, Muhd, Muhammad Azim A Jalil, and Mohammad Faizal Mohd Shariff. "Comparison of horizontal axis wind turbine (HAWT) and vertical axis wind turbine (VAWT)." International Journal of Engineering & Technology 7, no. 4.13 (2018): 74. http://dx.doi.org/10.14419/ijet.v7i4.13.21333.
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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.
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Mohan Kumar, Palanisamy, Krishnamoorthi Sivalingam, Teik-Cheng Lim, Seeram Ramakrishna, and He Wei. "Review on the Evolution of Darrieus Vertical Axis Wind Turbine: Large Wind Turbines." Clean Technologies 1, no. 1 (2019): 205–23. http://dx.doi.org/10.3390/cleantechnol1010014.
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The objective of the current review is to present the development of a large vertical axis wind turbine (VAWT) since its naissance to its current applications. The turbines are critically reviewed in terms of performance, blade configuration, tower design, and mode of failure. The early VAWTs mostly failed due to metal fatigue since the composites were not developed. Revisiting those configurations could yield insight into the future development of VAWT. The challenges faced by horizontal axis wind turbine (HAWT), especially in the megawatt capacity, renewed interest in large scale VAWT. VAWT provides a solution for some of the immediate challenges faced by HAWT in the offshore environment in terms of reliability, maintenance, and cost. The current rate of research and development on VAWT could lead to potential and economical alternatives for HAWT. The current summary on VAWT is envisioned to be an information hub about the growth of the Darrieus turbine from the kW capacity to megawatt scale.
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Horiuchi, Kenji, Izumi Ushiyama, and Kazuichi Seki. "Straight Wing Vertical Axis Wind Turbines: A Flow Analysis." Wind Engineering 29, no. 3 (2005): 243–52. http://dx.doi.org/10.1260/030952405774354840.
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This research examines the flow velocity characters around lift-based straight-wing vertical-axis wind turbines (SW-VAWT) by numerical simulation. The precision of the prediction technique was confirmed. Furthermore, we estimate the flow behaviour during the wind turbine rotation by using this numerical simulation technique, and evaluate the flow around the SW-VAWT. This paper presents an outline of the work and gives the results of the calculations.
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Guo, Jia, and Liping Lei. "Flow Characteristics of a Straight-Bladed Vertical Axis Wind Turbine with Inclined Pitch Axes." Energies 13, no. 23 (2020): 6281. http://dx.doi.org/10.3390/en13236281.
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Currently, vertical axis wind turbines (VAWT) are considered as an alternative technology to horizontal axis wind turbines in specific wind conditions, such as offshore farms. However, complex unsteady wake structures of VAWTs exert a significant influence on performance of wind turbines and wind farms. In the present study, instantaneous flow fields around and downstream of an innovative VAWT with inclined pitch axes are simulated by an actuator line model. Unsteady flow characteristics around the wind turbine with variations of azimuthal angles are discussed. Several fluid parameters are then evaluated on horizontal and vertical planes under conditions of various fold angles and incline angles. Results show that the total estimated wind energy in the shadow of the wind turbine with an incline angle of 30° and 150° is 4.6% higher than that with an incline angle of 90°. In this way, appropriate arrangements of wind turbines with various incline angles have the potential to obtain more power output in a wind farm.
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Mohammed, Gwani, Mamuda Buhari, Umar Muhammed Kangiwa, and John Danyaro. "Design, Fabrication and Performance Evaluation of Hybrid Vertical Axis Wind Turbine." International Journal for Modern Trends in Science and Technology 6, no. 6 (2020): 80–86. http://dx.doi.org/10.46501/ijmtst060618.
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Vertical axis wind turbines (VAWT) have attracted a lot of attention recently as an efficient tool in harnessing wind energy; however these types of wind turbine are faced with some challenges which affect their overall performance. The Darrieus rotor has difficulty to self-start by itself while the Savonius rotor has low efficiency. The performance of these turbines can be improved by combining the two VAWTs as one system. This paper presents the design of a hybrid VAWTs turbine. The Hybrid VAWTs combines the Darrieus rotor and the Savonius rotor as a single system to produce a high starting torque and enhanced efficiency. The Savonius rotor is placed at the centre of the three vertical blades of the Darrieus H-rotor to form the hybrid VAWTs. The hybrid VAWT was tested at four different wind speed i.e. V = 4.80 m/s, 4.50 m/s, 4.30 m/s and 3.90 m/s respectively. The performance of the hybrid VAWT was compared with the conventional straight bladed VAWT under similar experimental conditions. The obtained results showed that there is substantial improvement in the self-starting ability and coefficient of power (Cp). At V = 4.80 m/s, the Cp values for hybrid VAWT increased by 92% compared to straight bladed H-rotor VAWT. Similar improvement was also observed at wind speed of V = 4.50 m/s, 4.30 m/s, and 3.90 m/s where the Cp values increases by 71%, 10%, and 67% respectively compared to the straight bladed H-rotor.
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Junaidin, Buyung. "PERANCANGAN PURWARUPA VERTICAL AXIS WIND TUBINE (VAWT) SKALA KECIL." Angkasa: Jurnal Ilmiah Bidang Teknologi 9, no. 2 (2017): 29. http://dx.doi.org/10.28989/angkasa.v9i2.177.
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Konsumsi energi yang berasal dari bahan bakar fosil yang semakin tinggi dan ketersediannya di alam yang terbatas sehingga jumlahnya makin lama semakin berkurang, memaksa orang untuk mencari alternatif sumber energi lain. Energi angin menjadi salah satu energi alternatif yang penting dan diperhitungkan sejak adanya krisis energi dan isu lingkungan (polusi udara) akibat penggunaan bahan bakar fosil. Energi angin dimanfaatkan dengan cara mengubah gerakan angin menjadi energi listrik dengan turbin angin (wind turbine). Banyak turbin angin dengan skala besar yang telah dibuat atau dikembangkan di berbagai negara karena terbukti sangat efektif untuk menghasilkan energi listrik. Turbin angin skala kecil juga ikut dibuat dan dikembangkan hingga saat ini karena beberapa kelebihannya jika dibandingkan dengan turbin angin skala besar. Kelebihan itu diantaranya tidak terbatasnya daerah atau lokasi pemasangan turbin angin karena ukurannya yang kecil sehingga dapat ditempatkan di daerah seperti perkotaan. Untuk turbin angin skala kecil, jenis vertical axis wind turbine (vawt) sangatlah cocok digunakan di daerah perkotaan karena karakteristik VAWT yang dapat bergerak tanpa tergantung arah angin, hal ini sesuai dengan karakteristik angin perkotaan. Selain itu, VAWT dapat bergerak dan menghasilkan energi listrik pada kondisi kecepatan angin yang rendah. Penelitian ini fokus pada perancangan VAWT skala kecil yang dapat diaplikasikan pada kecepatan angin rendah dan berubah-ubah arah seperti karakteristik angin di perkotaan Indonesia serta analisis aerodinamika menggunakan metode double-multiple stream-tube (DMS).
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Cao, Yang, Xiao Ning Li, Guo Qing Wu, Xing Hua Chen, and Xiao Yan Tian. "Design and Optimization of Vertical Axis Wind Turbine." Applied Mechanics and Materials 150 (January 2012): 148–53. http://dx.doi.org/10.4028/www.scientific.net/amm.150.148.
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Wind power is a clean and renewable energy, and more and more countries in the world attach great importance to it and promote the development of the wind power industry. The current situation of wind turbines at home and abroad, the development, types, and characteristics were analyzed. The structural design of vertical axis wind turbine (VAWT) and aerodynamic theory of rotor blade were briefly introduced, the characteristic parameters in VAWT design were presented in this paper. Using finite element analysis method, the spindle which is the crucial component of VAWT under the extreme wind load was analyzed, and the corresponding results were obtained. Finally the wall thickness and the structure of spindle were improved and optimized to satisfy the engineering requirements of spindle.
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Brownstein, Ian D., Nathaniel J. Wei, and John O. Dabiri. "Aerodynamically Interacting Vertical-Axis Wind Turbines: Performance Enhancement and Three-Dimensional Flow." Energies 12, no. 14 (2019): 2724. http://dx.doi.org/10.3390/en12142724.
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This study examined three-dimensional, volumetric mean velocity fields and corresponding performance measurements for an isolated vertical-axis wind turbine (VAWT) and for co- and counter-rotating pairs of VAWTs with varying incident wind direction and turbine spacings. The purpose was to identify turbine configurations and flow mechanisms that can improve the power densities of VAWT arrays in wind farms. All experiments were conducted at a Reynolds number of R e D = 7.3 × 10 4 . In the paired arrays, performance enhancement was observed for both the upstream and downstream turbines. Increases in downstream turbine performance correlate with bluff–body accelerations around the upstream turbine, which increase the incident freestream velocity on the downstream turbine in certain positions. Decreases in downstream turbine performance are determined by its position in the upstream turbine’s wake. Changes in upstream turbine performance are related to variations in the surrounding flow field due to the presence of the downstream rotor. For the most robust array configuration studied, an average 14% increase in array performance over approximately a 50° range of wind direction was observed. Additionally, three-dimensional vortex interactions behind pairs of VAWT were observed that can replenish momentum in the wake by advection rather than turbulent diffusion. These effects and their implications for wind-farm design are discussed.
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Khammas, Farhan Ahmed, Kadhim Hussein Suffer, Ryspek Usubamatov, and Mohmmad Taufiq Mustaffa. "Overview of Vertical Axis Wind Turbine (VAWT) is one of the Wind Energy Application." Applied Mechanics and Materials 793 (September 2015): 388–92. http://dx.doi.org/10.4028/www.scientific.net/amm.793.388.
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This paper reviews the available types of wind turbine which is one of the wind energy applications. The authors intend to give investors a better idea of which turbine is suitable for a particular setting and to provide a new outlook on vertical axis wind turbines. Wind technology has grown substantially since its original use as a method to grind grains and will only continue to grow. Vertical-axis wind turbines are more compact and suitable for residential and commercial areas while horizontal-axis wind turbines are more suitable for wind farms in rural areas or offshore. However, technological advances in vertical axis wind turbines that are able to generate more energy with a smaller footprint are now challenging the traditional use of horizontal wind turbines in wind farms. Vertical axis wind turbines do not need to be oriented to the wind direction and offer direct rotary output to a ground-level load, making them particularly suitable for water pumping, heating, purification and aeration, as well as stand-alone electricity generation. The use of high efficiency Darrieus turbines for such applications is virtually prohibited by their inherent inability to self-start.
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Wasiati, S. W., F. A. Augusta, V. R. P. Purwanto, P. Wulandari, and A. Syahrirar. "Darrieus type vertical axis wind turbine (VAWT) design." Journal of Physics: Conference Series 1517 (April 2020): 012064. http://dx.doi.org/10.1088/1742-6596/1517/1/012064.
Full textDissertations / Theses on the topic "VAWT (vertical axis wind turbine)"
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Pearson, Charlie. "Vertical axis wind turbine acoustics." Thesis, University of Cambridge, 2014. https://www.repository.cam.ac.uk/handle/1810/245256.
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Increasing awareness of the issues of climate change and sustainable energy use has led to growing levels of interest in small-scale, decentralised power generation. Small-scale wind power has seen significant growth in the last ten years, partly due to the political support for renewable energy and the introduction of Feed In Tariffs, which pay home owners for generating their own electricity. Due to their ability to respond quickly to changing wind conditions, small-scale vertical axis wind turbines (VAWTs) have been proposed as an efficient solution for deployment in built up areas, where the wind is more gusty in nature. If VAWTs are erected in built up areas they will be inherently close to people; consequently, public acceptance of the turbines is essential. One common obstacle to the installation of wind turbines is noise annoyance, so it is important to make the VAWT rotors as quiet as possible. To date, very little work has been undertaken to investigate the sources of noise on VAWTs. The primary aim of this study was therefore to gather experimental data of the noise from various VAWT rotor configurations, for a range of operating conditions. Experimental measurements were carried out using the phased acoustic array in the closed section Markham wind tunnel at Cambridge University Engineering Department. Beamforming was used in conjunction with analysis of the measured sound spectra in order to locate and identify the noise sources on the VAWT rotors. Initial comparisons of the spectra from the model rotor and a full-scale rotor showed good qualitative agreement, suggesting that the conclusions from the experiments would be transferable to real VAWT rotors. One clear feature observed in both sets of spectra was a broadband peak around 1-2kHz, which spectral scaling methods demonstrated was due to laminar boundary layer tonal noise. Application of boundary layer trips to the inner surfaces of the blades on the model rotor was found to eliminate this noise source, and reduced the amplitude of the spectra by up to 10dB in the region of the broadband peak. This method could easily be applied to a full-scale rotor and should result in measurable noise reductions. At low tip speed ratios (TSR) the blades on a VAWT experience dynamic stall and it was found that this led to significant noise radiation from the upstream half of the rotor. As the TSR was increased the dominant source was seen to move to the downstream half of the rotor; this noise was thought to be due to the interaction of the blades in the downstream half of the rotor with the wake from the blades in the upstream half. It was suggested that blade wake interaction is the dominant noise source in the typical range of peak performance for the full-scale QR5 rotor. Different solidity rotors were investigated by using 2-, 3- and 4-bladed rotors and it was found that increasing the solidity had a similar effect to increasing the TSR. This is due to the fact that the induction factor, which governs the deflection of the flow through the rotor, is a function of both the rotor solidity and the TSR. With a large body of experimental data for validation, it was possible to investigate computational noise prediction methods. A harmonic model was developed that aimed to predict the sound radiated by periodic fluctuations in the blade loads. This model was shown to agree with similar models derived by other authors, but to make accurate predictions very high resolution input data was required. Since such high resolution blade loading data is unlikely to be available, and due to the dominance of stochastic sources, the harmonic model was not an especially useful predictive tool. However, it was used to investigate the importance of the near-field components of the sound radiated by the wind tunnel model to the acoustic array. It was shown that the near-field terms were significant over a wide range of frequencies, and the total spectrum was always greater than that of the far-field component. This implied that the noise levels measured by the acoustic array represented an upper bound on the sound radiated to the far-field, and hence that the latter would also be dominated by stochastic components. An alternative application of the harmonic model, which attempted to determine the blade loading harmonics from the harmonics in the sound field was proposed. This inversion method utilised a novel convex optimisation technique that was found to generate good solutions in the simulated test cases, even in the presence of significant random noise. The method was found to be insensitive at low frequencies, which made it ineffective for inverting the real microphone data, although this was shown to be at least partly due to the limitations imposed by the array size. In addition to the harmonic models, an empirical noise prediction method using the spectral scaling laws derived by \citet*{Brooks_1989} was trialled, and was found to be capable of making predictions that were in agreement with the measured data. The model was shown to be sensitive to the exact choice of turbulence parameters used and was also found to require good quality aerodynamic data to make accurate noise predictions. If such data were available however, it is expected that this empirical model would be able to make useful predictions of the noise radiated by a VAWT rotor.
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Hikkaduwa, Vithanage Ajith. "DESIGN AND PERFORMANCE ANALYSIS OF PITCHED-PLATE VERTICAL AXIS WIND TURBINE FOR DOMESTIC POWER GENERATION." Thesis, Högskolan i Gävle, Avdelningen för bygg- energi- och miljöteknik, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:hig:diva-17428.
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Wind energy is identified a promising energy resource in Sri Lanka. Therefore, it is important to use proper technologies for efficient energy capturing in order to minimize cost of energy. Small scale wind turbines are usually installed in constricted places (particularly in urban areas) where wind flow is turbulent and difficult to predict. Savonious type vertical axis wind turbines are important due to several reasons such as good response to turbulent winds, high initial torque, low cost, low noise, less maintenance.In this study, a modified flat plate type Savonius wind rotor was proposed to cost effectively harness wind energy in constricted places. Generally, vertical axis wind turbines (VAWT) are less efficient than horizontal axis wind turbines, one reason behind this issue is wind force difference between the 2 sides of the axis is small and due to this reason torque is small and power generation capacity is less.A prototype of the proposed VAWT was fabricated and the performance was determined by acquiring experimental data. Artificial wind blow which was generated by a huge fan was used to measure rotational speed and torque characteristics at varying wind speeds. Data were collected with 1-second sampling time and a data acquisition system was developed under this study. In the proposed design one side of the turbine blades are facing the wind direction in order to capture maximum force while other side is edging the blades to have minimum opposite torque. With this concept it is expected to maximize the torque of the axis and generate more power. A sort of a passive pitch mechanism is therefore utilized in order to save energy and simplify the system. Turbine blades are simple flat plates and it eliminates usage of complex aero foils. Due to the simplicity of this design it would be possible to use this turbine for domestic electricity generation at affordable costs.Nowadays, net metering systems are being promoted in Sri Lanka and it would be beneficial to introduce low cost VAWT which operates at low winds as well as turbulent wind conditions. Based on typical household hourly load profile, viability of proposed vertical axis wind turbine was evaluated by considering rural and urban wind regimes in Sri Lanka. The costs of wind energy at two selected locations were determined in the context of net metering.
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Bülow, Fredrik. "A Generator Perspective on Vertical Axis Wind Turbines." Doctoral thesis, Uppsala universitet, Elektricitetslära, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-197855.
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The wind energy conversion system considered in this thesis is based on a vertical axis wind turbine with a cable wound direct drive PM generator. Diode rectifiers are used to connect several such units to a single DC-bus and a single inverter controls the power flow from the DC-bus to a utility grid. This work considers the described system from a generator perspective i.e. the turbine is primarily seen as a torque and the inverter is seen as a controlled load. A 12 kW VAWT prototype with a single turbine has been constructed within the project. The power coefficient of this turbine has been measured when the turbine is operated at various tip speed ratios. This measurement determines both how much energy the turbine can convert in a given wind and at what speed the turbine should be operated in order to maximise the energy capture. The turbine torque variation during the revolution of the turbine has also been studied. A PM generator prototype has been constructed in order to study power loss in the stator core at low electrical frequencies. Heat exchange between the stator and the air-gap between the stator and the rotor has been studied. Heat exchange between the stator and the air-gap is increased by turbulence caused by the rotor. The generator was also used in a demonstration of a DC-grid where two diode rectified PM generators supplied power to a single DC load. An initial study of an inverter suitable for grid connection of the 12 kW PM generator has been performed. Several turbine control strategies are evaluated in simulations. The control strategies only require the parameter "turbine speed" to determine the optimal system load.
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D'Ambrosio, Marco, and Marco Medaglia. "Vertical Axis Wind Turbines: History, Technology and Applications." Thesis, Halmstad University, Halmstad University, School of Business and Engineering (SET), 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:hh:diva-4986.
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<p>In this Master Thesis a review of different type of vertical axis wind turbines (VAWT) and a preliminary investigation of a new kind of VAWT are presented.</p><p>After an introduction about the historical background of wind power, the report deals with a more accurate analysis of the main type of VAWT, showing their characteristics and their operations. The aerodynamics of the wind turbines and a review of different type on generators that can be used to connect the wind mill to the electricity grid are reported as well.</p><p>Several statistics are also presented, in order to explain how the importance of the wind energy has grown up during the last decades and also to show that this development of the market of wind power creates new opportunity also for VAWT, that are less used than the horizontal axis wind turbine (HAWT).</p><p>In the end of 2009 a new kind of vertical axis wind turbine, a giromill 3 blades type, has been built in Falkenberg, by the Swedish company VerticalWind. The tower of this wind turbine is made by wood, in order to get a cheaper and more environment friendly structure, and a direct driven synchronous multipole with permanent magnents generator is located at its bottom. This 200 kW VAWT represents the intermediate step between the 12 kW prototype, built in collaboration with the Uppsala University, and the common Swedish commercial size of 2 MW, which is the goal of the company.</p><p>A preliminary investigation of the characteristics of this VAWT has been done, focusing in particular on the value of the frequency of resonance of the tower, an important value that must be never reached during the operative phase in order to avoid serious damage to all the structure, and on the power curve, used to evaluate the coefficient of power (Cp) of the turbine. The results of this investigation and the steps followed to get them are reported. Moreover a energy production analysis of the turbine has been done using WindPro, as well as a comparison with and older type on commercial VAWT.</p>
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Möllerström, Erik. "Vertical Axis Wind Turbines : Tower Dynamics and Noise." Licentiate thesis, Högskolan i Halmstad, Energiteknik, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-242267.
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Vertical axis wind turbines (VAWTs) have with time been outrivaled by the today common and economically feasible horizontal axis wind turbines (HAWTs). However, VAWTs have several advantages such as the possibility to put the drive train at ground level, lower noise emissions and better scaling behavior which still make them interesting for research. The work within this thesis is made in collaboration between the Department of Construction and Energy Engineering at Halmstad University and the Division for Electricity at Uppsala University. A 200 kW VAWT owned by the latter and situated close to Falkenberg in the southwest of Sweden has been the main subject of the research even if most learnings has been generalized to fit a typical vertical turbine. This particular turbine has a wooden tower which is semi-guy-wired, i.e. the tower is both firmly attached to the ground and supported by guy-wires. This thesis has two main topics both regarding VAWTs: eigenfrequency of the tower and the noise generated from the turbine. The eigenfrequency of a semi-guy-wired tower is studied and an analytical expression describing this is produced and verified by experiments and simulations. The eigenfrequency of the wire itself and how it is affected by wind load are also studied. The noise characteristics of VAWTs have been investigated, both theoretically and by noise measurement campaigns. Both noise emission and frequency distribution of VAWTs has been studied. The work has resulted in analytical expressions for tower and wire eigenfrequency of a semi-guy-wired tower as well as recommendations for designing future towers for VAWTs. The noise emission of VAWTs has been studied and proven low compared to HAWTs. The noise frequency distribution of the 200 kW VAWT differs significantly from that of a similar size HAWTs with for example lower levels for frequencies below 3000 Hz.
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Almohammadi, Khaled Mohammad. "Optimization of a CFD based design of a straight blade vertical axis wind turbine (SB-VAWT)." Thesis, University of Leeds, 2014. http://etheses.whiterose.ac.uk/7021/.
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Enhancing the extraction of the wind energy in urban regions using micro and small wind turbines becomes a necessity with the increasing power consumption. The focus of this thesis is to optimize micro and small SB-VAWT performance by analysing CFD techniques, several modelling characteristics and design parameters where the performance is measured by the power coefficient. In this thesis, the SB-VAWT is optimized by employing sophisticated optimization techniques, namely such as the GA and the NLPQL, which are employed on response surfaces created from several design sampling methods. The optimization is based on three parameters, namely, camber, thickness and chord. A novel airfoil geometry has been introduced. The new airfoil geometry increases the power coefficient by about 42% at the optimized tip speed ratio and increases the peak of the turbine power coefficient by 4% at a low tip speed ratio. However, it was necessary to assess the computational process by examining the mesh and the computational method in order to ensure that the optimized design of the SB-VAWT is only resulting from the optimization process. Therefore, several physical phenomena have been investigate including the dynamic stall, laminar-turbulent transition and laminar bubbles. Also, several computational techniques and schemes have been critically analysed. Further, several mesh independency techniques have been implemented and it was found that the fitting method may be suitable for SB-VAWTs due to the presence of oscillations in the convergence of the power coefficient which may be caused by the presence of dynamic stall, laminar-turbulent transition and laminar bubbles. The physics of these flow conditions are only captured when the transitional model is employed. The optimization of the SB-VAWT in this thesis is based on a 2D model. It was found that the 2D model produce a results similar to the 3D model at mid span of the turbine blade. Therefore, the 2D model of the turbine sufficiently represents the flow physics around the blades qualitatively, and thus the 2D model is employed for the optimization of the SB-VAWT.
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Zhao, Jiaming. "Experimental Study of Effects of Leading-Edge Structures on the Dynamic Stall of a Vertical Axis Wind Turbine Airfoil." Thesis, North Dakota State University, 2020. https://hdl.handle.net/10365/32053.
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Vertical axis wind turbine, developed as one of the main methods to utilize the wind energy, has a promising future; however, the major issue to limit its performance is the uneven loading on the blade during operation. Flow control mechanisms have been employed in the aerodynamic field to improve the performance of airfoils. In this study, two types of leading-edge structures, including flexible leading-edge and leading-edge roughness, are experimentally investigated to analyze their effects on altering the aerodynamic characteristics of NACA 0018 airfoil under steady flow condition and dynamic pitching condition. Current experimental results indicate that 1) during the steady flow condition, both of leading-edge structures contribute to the delay of the static stall; 2) for the dynamic pitching process, the leading-edge structures either delayed the dynamic stall angle or increased the area of the coefficient of pressure loop as a function of angle of attack.
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Kjellin, Jon. "Vertical Axis Wind Turbines : Electrical System and Experimental Results." Doctoral thesis, Uppsala universitet, Elektricitetslära, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-182438.
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The wind power research at the division of Electricity at Uppsala University is aimed towards increased understanding of vertical axis wind turbines. The considered type of wind turbine is an H-rotor with a directly driven synchronous generator operating at variable speed. The experimental work presented in this thesis comprises investigation of three vertical axis wind turbines of different design and size. The electrical, control and measurement systems for the first 12 kW wind turbine have been designed and implemented. The second was a 10 kW wind turbine adapted to a telecom application. Both the 12 kW and the 10 kW were operated against dump loads. The third turbine was a 200 kW grid-connected wind turbine, where control and measurement systems have been implemented. Experimental results have shown that an all-electric control, substituting mechanical systems such as blade-pitch, is possible for this type of turbine. By controlling the rectified generator voltage, the rotational speed of the turbine is also controlled. An electrical start-up system has been built and verified. The power coefficient has been measured and the stall behaviour of this type of turbine has been examined. An optimum tip speed ratio control has been implemented and tested, with promising results. Use of the turbine to estimate the wind speed has been demonstrated. This has been used to get a faster regulation of the turbine compared to if an anemometer had been used.
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Möllerström, Erik. "Noise, eigenfrequencies and turbulence behavior of a 200 kW H-rotor vertical axis wind turbine." Doctoral thesis, Uppsala universitet, Elektricitetslära, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-316385.
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Vertical-axis wind turbines (VAWTs) have with time been outrivaled by the today more common and economically feasible horizontal-axis wind turbines (HAWTs). However, VAWTs have several advantages which still make them interesting, for example, the VAWTs can have the drive train at ground level and it has been argued that they have lower noise emission. Other proposed advantages are suitability for both up-scaling and floating offshore platforms. The work within this thesis is made in collaboration between Halmstad University and Uppsala University. A 200-kW semi-guy-wired VAWT H-rotor, owned by Uppsala University but situated in Falkenberg close to Halmstad, has been the main subject of the research although most results can be generalized to suit a typical H-rotor. This thesis has three main topics regarding VAWTs: (1) how the wind energy extraction is influenced by turbulence, (2) aerodynamical noise generation and (3) eigenfrequencies of the semi-guy-wired tower. The influence from turbulence on the wind energy extraction is studied by evaluating logged operational data and examining how the power curve and the tip-speed ratio for maximum Cp is impacted by turbulence. The work has showed that the T1-turbine has a good ability to extract wind energy at turbulent conditions, indicating an advantage in energy extraction at turbulent sites for VAWTs compared to HAWTs.The noise characteristics are studied experimentally, and models of the two most likely aerodynamic noise mechanisms are applied. Here, inflow-turbulence noise is deemed as the prevailing noise source rather than turbulent-boundary-layer trailing-edge noise (TBL-TE) which is the most important noise mechanism for HAWTs. The overall noise emission has also been measured and proven low compared to similar sized HAWTs. The eigenfrequencies of a semi-guy-wired tower are also studied. Analytical expressions describing the first-mode eigenfrequency of both tower and guy wire has been derived and verified by experiments and simulations.
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Bah, Elhadji Alpha Amadou. "Numerical investigation on the use of multi-element blades in vertical-axis wind turbines." Diss., Georgia Institute of Technology, 2015. http://hdl.handle.net/1853/53501.
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The interest in sustainable forms of energy is being driven by the anticipated scarcity of traditional fossil fuels over the coming decades. There is also a growing concern about the effects of fossil fuel emissions on human health and the environment. Many sources of renewable energy are being researched and implemented for power production. In particular, wind power generation by horizontal- and vertical-axis wind turbines is very popular.
Vertical-axis wind turbines (VAWTs) have a relative construction simplicity compared to horizontal-axis wind turbines (HAWTs). However, VAWTs present specific challenges that may hinder their performance. For instance, they are strongly affected by dynamic stall. A significant part of the kinetic energy contained in the oncoming wind is lost in swirl and vortices. As a result, VAWTs have lower power production compared to HAWTs.
First, the present work is aimed at the study of the aerodynamics of straight-bladed VAWTs (SB-VAWTs). Empirical calculations are conducted in a preliminary work. Then a two-dimensional double multiple streamtube (DMST) approach supported by a two-dimensional numerical study is implemented. The dynamic stall and aerodynamic performance of the rotor are investigated. A VAWT-fitted dynamic stall model is implemented. Computational fluid dynamics (CFD) simulations are conducted to serve as reference for the DMST calculations. This three-pronged approach allows us to efficiently explore multiple configurations. The dynamic stall phenomenon is identified as a primary cause of performance loss.
The results in this section validate the DMST model as a good replacement for CFD analysis in early phase design provided that a good dynamic stall model is used.
After having identify the primary cause of performance loss, the goal is to investigate the use to dual-element blades for alleviating the effect of dynamic stall, thereby improving the performance of the rotor. The desirable airfoil characteristics are defined and a parametric analysis conducted. In the present study the parameters consists of the size of the blade elements, the space between them, and their relative orientation. The performance of the rotor is calculated and compared to the baseline.
The results highlight the preeminence of the two-element configuration over the single-element provided that the adequate parametric study is conducted beforehand.
A performance enhancement is obtained over a large range of tip speed ratios. The starting characteristics and the operation stability are also improved.
Finally, an economic analysis is conducted to determine the cost of energy and thus the financial viability of such a project. The Great Coast of Senegal is selected as site of operation. The energy need and sources of this region are presented along with its wind energy potential. The cost evaluation shows the economic viability by comparing the cost of energy to the current energy market prices.
Books on the topic "VAWT (vertical axis wind turbine)"
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Taylor, Derek. Field performance testing of an 8.8 m diameter "V" type vertical axis wind turbine. 1988.
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Wolf, E. L. Wind, hydro and tides Fully sustainable energy. Oxford University Press, 2018. http://dx.doi.org/10.1093/oso/9780198769804.003.0008.
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Wind-turbine science and technology is outlined, following the work of Betz. Rotor design, blade construction and aspects of electric power generation are described, principally for large horizontal-axis devices, with some mention of vertical axis wind turbines. Hydropower and pumped storage are treated, with mention of Francis and Kaplan turbines. A summary of tidal energy is included. We now go into detail on some aspects of these topics. As these forms of energy come either from the Sun (in an indirect fashion) or from the motion of the Earth and Moon, they are available on an indefinite term into the future.
Book chapters on the topic "VAWT (vertical axis wind turbine)"
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Ruffino, Giuseppe, Susan Schaar, Daniel Lehser-Pfeffermann, et al. "Numerical Simulation and Measurement for Location Optimization of a Vertical Axis Wind Turbine (VAWT)." In Wind Energy Exploitation in Urban Environment. Springer International Publishing, 2019. http://dx.doi.org/10.1007/978-3-030-13531-7_3.
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Vennila Sigamani, Sankgeeth, Shami Jose Jose Robin, Arun Prakash Chandran, and B. Anand Ronald. "Effect of Input Velocity on the Output of Vertical Axis Wind Turbine (VAWT)." In Lecture Notes in Mechanical Engineering. Springer Singapore, 2020. http://dx.doi.org/10.1007/978-981-15-4745-4_93.
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ArunPrakash, C., P. PonsuganthIlangovan, Nitin Joy, and R. Subramanian. "Numerical Study of Blade Profiles of Vertical Axis Wind Turbine (VAWT) with Bidirectional Wind Flow in Highway Roads." In Advances in Energy Research, Vol. 2. Springer Singapore, 2020. http://dx.doi.org/10.1007/978-981-15-2662-6_33.
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Shchur, Ihor, Andrii Lozinskyi, Bohdan Kopchak, Yurii Biletskyi, and Vsevolod Shchur. "Passive Stall Control Systems of Power Limitation Modes for Vertical Axis Wind Turbines (VAWT)." In Lecture Notes in Electrical Engineering. Springer International Publishing, 2017. http://dx.doi.org/10.1007/978-3-319-63949-9_8.
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Hirschl, Alexander, Mauro Peppoloni, and Kurt Leonhartsberger. "Evaluation of the Causes of Vibration and Oscillation in a Vertical Axis Small Wind Turbine (VASWT) and Its Reduction." In Wind Energy Exploitation in Urban Environment. Springer International Publishing, 2019. http://dx.doi.org/10.1007/978-3-030-13531-7_6.
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Koch, Grady, and Elias Koch. "The Vertical-Axis Turbine." In LEGO Wind Energy. Apress, 2019. http://dx.doi.org/10.1007/978-1-4842-4439-5_3.
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Pagnini, Luisa, Giuseppe Piccardo, Maria Pia Repetto, and Giuseppe Riotto. "Dynamic Identification of a Vertical Axis Wind Turbine." In Wind Energy Exploitation in Urban Environment. Springer International Publishing, 2019. http://dx.doi.org/10.1007/978-3-030-13531-7_10.
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Elmnefi, Mohamed S., and Ahmed M. Bofares. "The Techniques Used for Performance Prediction of Vertical-Axis Wind Turbines (VAWTs)." In Exergy for A Better Environment and Improved Sustainability 1. Springer International Publishing, 2018. http://dx.doi.org/10.1007/978-3-319-62572-0_12.
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Kusnick, J. F., and D. E. Adams. "Vertical Axis Wind Turbine Operational Modal Analysis in Sheared Wind Flow." In Topics in Experimental Dynamics Substructuring and Wind Turbine Dynamics, Volume 2. Springer New York, 2012. http://dx.doi.org/10.1007/978-1-4614-2422-2_29.
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Araszkiewicz, Piotr, Włodzimierz Gnarowski, Paweł Abratowski, Michał Ćmil, and Michał Pokorski. "Intelligent 1 kW Vertical Axis Wind Turbine—Simplified Analytical Model." In Proceedings of the 13th International Scientific Conference. Springer International Publishing, 2017. http://dx.doi.org/10.1007/978-3-319-50938-9_4.
Full textConference papers on the topic "VAWT (vertical axis wind turbine)"
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Zilberman, Moshe. "Optimized Small Vertical Axis Wind Turbine (VAWT), Phase II." In AIAA Propulsion and Energy 2021 Forum. American Institute of Aeronautics and Astronautics, 2021. http://dx.doi.org/10.2514/6.2021-3366.
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Chen, Chien-Chang, and Cheng-Hsiung Kuo. "Simulation on Performances of Vertical Axis Wind Turbine." In ASME 2010 10th Biennial Conference on Engineering Systems Design and Analysis. ASMEDC, 2010. http://dx.doi.org/10.1115/esda2010-24207.
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This study employs the commercialized computational fluid dynamics software (Ansys/Fluent), with the user’s defined technique, to simulate the unsteady flow structures around the small-size vertical axis wind turbines (VAWT) with three straight blades. This study addresses the effects of the collective variations of the pitch angle (within ± 10°) on the performance of the VAWT system. The results of the transient (acceleration) stage will be employed to evaluate the self-starting ability. While the vertical axis wind turbine (VAWT) reaches a steady rotating stage, the detailed flow structures, the vorticity fields, the pressure distributions around, and the forces on the airfoils at various azimuthal positions will be addressed. For the blades with a negative pitch angle (θ = −10°), has the peak value of the moment coefficient within one revolution is the largest which will provide the largest starting torque to drive the VAWT system more easily. However, in this case, the moment coefficients are negative within some part of the period. This cancels part of the positive moment within one revolution, thus the efficiency is reduced at this pitch angle. For the case with positive pitch angle (θ = 10°), the area under the moment coefficient curve is the smallest and the time elapse of large moment coefficient is relatively short. Thus the efficiency and the starting torque are the lowest among thee pitch angles.
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Bah, Elhadji A. A., Lakshmi N. Sankar, and Jechiel I. Jagoda. "Numerical Investigations on the Use of Multi-Element Airfoils for Vertical Axis Wind Turbine Configurations." In ASME 2013 Gas Turbine India Conference. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/gtindia2013-3505.
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Vertical axis wind turbines (VAWT) have a relatively simple, rugged construction compared to HAWTs. However, vertical-axis wind turbines have numerous challenges that may hinder their performance. For instance they are strongly affected by dynamic stall at low tip speed ratios. A significant part of the kinetic energy contained in the oncoming wind is lost in swirl and vortices. As a result, VAWTs have a lower power production and efficiency compared to HAWTs. In an effort to alleviate the adverse effects of dynamic stall phenomena, the present study explores the use of two-element airfoils. A comparative study of single element and dual element VAWT configurations for representative VAWT turbines is given. The benefits of dual-element configurations are analyzed through a detailed flow visualization study of the single and two-element VAWT configurations at various azimuthal locations for a representative tip speed ratio. Analysis of these qualitative phenomena is complemented by a discussion on quantitative data for torque, surface pressure distributions, and airloads.
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Kweder, Jonathan, Patrick Wildfire, Christina Yarborough, and James E. Smith. "Design of a Vertical-Axis Wind Turbine Test Facility." In ASME 2009 3rd International Conference on Energy Sustainability collocated with the Heat Transfer and InterPACK09 Conferences. ASMEDC, 2009. http://dx.doi.org/10.1115/es2009-90088.
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Physical simulations of fatigue and wear of a vertical axis wind turbine (VAWT) are extremely complex and difficult to evaluate both analytically and numerically. The primary difficulty is simulating the fatigue at the point that the airfoil attaches to the wind turbine structure. Physical testing of VAWT models would provide a simpler method of analyzing the dynamics of a prototype. However, accurate reproduction of the aerodynamic loading imposed on a VAWT body due to the rotational wake is difficult to replicate. To truly incorporate a real world environment, the test facility needs to be exposed to a random, but measurable environment. This leads to the design and development of an outdoor wind turbine test facility. This proposed test facility will consist of an outdoor structure equipped with a 350 horsepower electric motor to turn an 88 inch diameter propeller which will drive the wind turbine model at specific rotational speeds. The propeller will be able to simulate wind speeds over the entire spectrum of 0 to 75 feet per second. The aerodynamic control of the freestream velocity and in turn, the model, will provide an accurate representation of the aerodynamic loadings experienced by the wind turbines tested. In addition to structural testing, this facility will introduce measurable environmental effects, such as wind gusts, pressure variation, and temperature changes to the model in order to create an accurate setting under which the model can be studied.
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Seralathan, Sivamani, Micha Premkumar Thomai, Rian Leevinson Jayakumar, Basireddy Venkata Lokesh Reddy, and Hariram Venkatesan. "Experimental and Numerical Assessment of Cross Flow Vertical Axis Wind Turbine." In ASME 2019 Gas Turbine India Conference. American Society of Mechanical Engineers, 2019. http://dx.doi.org/10.1115/gtindia2019-2427.
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Abstract Due to increase in energy demand along with environmental awareness, the attention is shifting towards renewable energy sources. A wind turbine developed from Banki water turbine is used in this study as it starts at low-wind speeds and has high starting torque. Experimental investigations are carried out on a test rig equipped with open jet wind tunnel with wind velocity varying from 7 to 11 m/s. Later, 3D steady-state numerical analyses are performed using ANSYS CFX for better understanding of the flow physics of cross flow VAWT. The experimental investigations revealed that cross flow VAWT has a good self-starting ability at relatively low-wind speeds. A peak power coefficient (Cp, max) value of 0.059 is observed for the tip speed ratio (λ) of 0.30. As the tip speed ratio is raised further, the Cp value is observed to decrease gradually. The numerical simulations reveal the reason for the drop in Cp value. This is due to lessening of positive interaction between the flow and cross flow VAWT blades at higher λ due to vortex formation. The torque coefficient is found to decrease almost linearly from a peak value of around 0.49 at λ = 0 to a value of 0 around λ = 0.60. Polar plot between angle and torque shows that torque output of the turbine is nearly same in all directions which reinforce the potency of cross flow VAWT to be omni-directional as it produces the same performance regardless of wind directions.
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Untaroiu, Alexandrina, Archie Raval, Houston G. Wood, and Paul E. Allaire. "Boundary Layer Control for a Vertical Axis Wind Turbine Using a Secondary-Flow Path System." In ASME 2011 Turbo Expo: Turbine Technical Conference and Exposition. ASMEDC, 2011. http://dx.doi.org/10.1115/gt2011-46552.
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Vertical axis wind turbines (VAWTs) have typically lower efficiency compared to their horizontal counterparts (HAWTs), but are attractive for places where taller structures are prohibited, as well as for regions where available wind speeds are lower. For HAWTs, the blades are always perpendicular to the incoming wind, providing a continuous thrust throughout the rotation. Contrary to HAWTs, VAWTs have advancing blades and retreating blades, where blades backtrack against the wind, causing lower efficiency. Hence, any modifications that can be made to improve the efficiency of VAWTs can be beneficial to the wind industry. Passive flow control permits the airfoil geometry to be modified by means of grooves or slots without requiring heavy mechanisms or actuators. Hence, this form of boundary layer control seems advantageous for wind turbines, so that minimal amount of maintenance is required, while complexity of the turbine is not significantly increased. Such modification changes the boundary layer over an airfoil reducing flow separation and reversed flow. This study introduces a new form of passive flow control: Secondary-flow control system, which works on the principle of mass removal, eliminating flow separation at different apparent angles of attack in a VAWT. CFD analysis is used to investigate passive flow control for the airfoils NACA8H12 and LS0417 in a three-bladed VAWT configuration. A secondary flow path is initially designed and optimized in a single airfoil configuration, and then used to adjust the wind turbine blade design. The effects of secondary-flow control system in a VAWT design configuration are investigated by comparison with the non-modified airfoil design. The CFD results indicate that secondary-flow path system can be used to modify and control the boundary layer for a wind turbine. It is believed that secondary-flow control system incorporated in VAWT design has potential for improving turbine efficiency. Further research should be conducted to optimize the secondary-flow path system according to the shape of the airfoil in a 3D VAWT configuration, so that blades interference can be captured.
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Wilhelm, Jay P., Chad C. Panther, Franz A. Pertl, and James E. Smith. "Vortex Analytical Model of a Circulation Controlled Vertical Axis Wind Turbine." In ASME 2009 3rd International Conference on Energy Sustainability collocated with the Heat Transfer and InterPACK09 Conferences. ASMEDC, 2009. http://dx.doi.org/10.1115/es2009-90348.
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A possible method for modeling a Circulation Controlled - Vertical Axis Wind Turbine (CC-VAWT) is a vortex model, based upon the circulation of a turbine blade. A vortex model works by continuously calculating the circulation strength and location of both free and blade vortices which are shed during rotation. The vortices’ circulation strength and location can then be used to compute a velocity at any point in or around the area of the wind turbine. This model can incorporate blade wake interactions, unsteady flow conditions, and finite aspect ratios. Blade vortex interactions can also be studied by this model to assist designers in the avoidance of adverse turbulent operational regions. Conventional vertical axis wind turbine power production is rated to produce power in an operating wind speed envelope. These turbines, unless designed specifically for low speed operation require rotational start-up assistance. The VAWT blade can be augmented to include circulation control capabilities. Circulation control can prolong the trailing edge separation and can be implemented by using blowing slots located adjacent to a rounded trailing edge surface; the rounded surface of the enhanced blade replaces the sharp trailing edge of a conventional airfoil. Blowing slots of the CC-VAWT blade are located on the top and bottom trailing edges and are site-controlled in multiple sections along the span of the blade. Improvements in the amount of power developed at lower speeds and the elimination or reduction of start-up assistance could be possible with a CC-VAWT. In order to design for a wider speed operating range that takes advantage of circulation control, an analytical model of a CC-VAWT would be helpful. The primary function of the model is to calculate the aerodynamic forces experienced by the CC-VAWT blade during various modes of operation, ultimately leading to performance predictions based on power generation. The model will also serve as a flow visualization tool to gain a better understanding of the effects of circulation control on the development and interactions of vortices within the wake region of the CC-VAWT. This paper will describe the development of a vortex analytical model of a CC-VAWT.
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Wilhelm, Jay P., Chad Panther, Franz A. Pertl, and James E. Smith. "Momentum Analytical Model of a Circulation Controlled Vertical Axis Wind Turbine." In ASME 2009 3rd International Conference on Energy Sustainability collocated with the Heat Transfer and InterPACK09 Conferences. ASMEDC, 2009. http://dx.doi.org/10.1115/es2009-90352.
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A possible method for analytically modeling a CC-VAWT (Circulation Controlled Vertical Axis Wind Turbine) is the momentum model, based upon the conservation of momentum principal. This model can consist of a single or multiple stream tubes and/or upwind and downwind partitions. A large number of stream tubes and the addition of the partition can increase the accuracy of the model predictions. The CC-VAWT blade has blowing slots located on the top and bottom trailing edges and have the capability to be site controlled in multiple sections along the span of the blade. The turbine blade, augmented to include circulation control capabilities, replaces the sharp trailing edge of a standard airfoil with a rounded surface located adjacent to the blowing slots. Circulation control (CC), along with a rounded trailing edge, induces the Coanda effect, entraining the flow field near the blowing slots thus preventing or delaying separation. Ultimately, circulation control adds momentum due to the mass flow of air coming out of the blowing slots, but is negligible compared to the momentum of the free stream air passing through the area of the turbine. In order to design for a broader range of operating speeds that will take advantage of circulation control, an analytical model of a CC-VAWT is helpful. The analytical modeling of a CC-VAWT could provide insight into the range of operational speeds in which circulation control is beneficial. The ultimate goal is to increase the range of operating speeds where the turbine produces power. Improvements to low-speed power production and the elimination or reduction of startup assistance could be possible with these modifications. Vertical axis wind turbines are typically rated at a particular ratio of rotational to wind speed operating range. In reality, however, wind speeds are variant and stray from the operating range causing the power production of a wind turbine to suffer. These turbines, unless designed specifically for low speed operation, may require rotational startup assistance. The added lift due to circulation control at low wind speeds, under certain design conditions, will allow the CC-VAWT to produce more power than a conventional VAWT of the same size. Circulation control methods, such as using blowing slots on the trailing edge are modeled as they are applied to a VAWT blade. A preliminary CC-VAWT was modeled using a standard NACA 0018 airfoil, modified to include blowing slots and a rounded trailing edge. This paper describes an analytical momentum model that can be used to predict the preliminary performance of a CC-VAWT.
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Hosseini, Arian, and Navid Goudarzi. "CFD and Control Analysis of a Smart Hybrid Vertical Axis Wind Turbine." In ASME 2018 Power Conference collocated with the ASME 2018 12th International Conference on Energy Sustainability and the ASME 2018 Nuclear Forum. American Society of Mechanical Engineers, 2018. http://dx.doi.org/10.1115/power2018-7488.
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Wind energy has become a dominant source of renewable energy during the past decade. Current hybrid wind turbines are primarily designed and manufactured based on a combination of aerodynamic properties for both Darrieus and Savonius turbines. In this work, the aerodynamic performance characteristics of a smart vertical axis wind turbine (VAWT) with an electro-magnetic switch mechanism for dis-/engagement mechanism is studied analytically and numerically. The proposed novel VAWT offers a high start-up torque by a Savonius turbine and high power coefficient values by a Darrieus turbine. The switch mechanism can further improve the system efficiency by running the turbines together or independently. The proposed hybrid VAWT was modeled as a combined Savonius-type Bach turbine and a 3-bladed H-Darrieus turbine. The hybrid turbine has a self-startup feature and reaches a coefficient of power (Cp) of over 40%. The turbine is also estimated to cover a wide operational range up to TSR 6. The follow on research phases of the project include studying the proposed smart VAWT experimentally and validating the results with those obtained through computational analysis.
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Wilhelm, Jay P., Emily D. Pertl, Franz A. Pertl, and James E. Smith. "Performance Predictions of a Circulation Controlled-Vertical Axis Wind Turbine With Solidity Control." In ASME 2009 3rd International Conference on Energy Sustainability collocated with the Heat Transfer and InterPACK09 Conferences. ASMEDC, 2009. http://dx.doi.org/10.1115/es2009-90350.
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Conventional straight bladed vertical axis wind turbines are typically designed to produce maximum power at tip speed ratio, but power production can suffer when operating outside of the design range. These turbines, unless designed specifically for low speed operation, may require rotational startup assistance. Circulation control methods, such as using blowing slots on the trailing edge could be applied to a Vertical Axis Wind Turbine (VAWT) blade. Improvements to the amount of power developed at lower speeds and elimination or reduction of startup assistance could be possible with this lift augmentation. Selection of a beneficial rotor solidity and control over when to utilize the blowing slots for the CC-VAWT (Circulation Controlled-Vertical Axis Wind Turbine) appears to have a profound impact on overall performance. Preliminary performance predictions indicate that at a greater range of rotor solidities, the CC-VAWT can have overall performance levels that exceed a conventional VAWT. This paper describes the performance predictions and solidity selection of a circulation controlled vertical axis wind turbine that can operate at higher overall capture efficiencies than a conventional VAWT.
Reports on the topic "VAWT (vertical axis wind turbine)"
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Mallick, Kaushik, Don Radford, Nate Bachman, David Snowberg, Michael Stewart, and W. Scott Carron. Vertical Axis Wind Turbine (VAWT) with Thermoplastic Composite Blades. Office of Scientific and Technical Information (OSTI), 2019. http://dx.doi.org/10.2172/1650138.
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Searcy, Chad, Steve Perryman, Dilip Maniar, D. Todd Griffith, and Brandon Lee Ennis. Optimal Floating Vertical-Axis Wind Turbine Platform Identification Design and Cost Estimation. Office of Scientific and Technical Information (OSTI), 2018. http://dx.doi.org/10.2172/1466529.
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Ralph, M. Data logger for the 34-meter vertical axis wind turbine test bed. Office of Scientific and Technical Information (OSTI), 1990. http://dx.doi.org/10.2172/6909607.
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Mitchell, M., and A. Murphy. Fatigue behavior of vertical axis wind turbine airfoils with two weld configurations. Office of Scientific and Technical Information (OSTI), 1989. http://dx.doi.org/10.2172/5414835.
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Stephenson, W. A. Test plan for the 34 meter vertical axis wind turbine test bed located at Bushland, Texas. Office of Scientific and Technical Information (OSTI), 1986. http://dx.doi.org/10.2172/6672744.
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