Blade Design

Conventional Thai sail windmill is a horizontal axis wind turbine for which a rotor is mounted in upstream position, upwind type, and there is no yaw control system. A yaw control system is mostly preferred for all horizontal axis wind turbines because it can help rotor face perpendicularly to all wind directions in order to avoid wind energy loss so that it can produce more annual energy production. Both small and medium scale of the upwind type normally can have a passive yaw control system by using a tail fin, while the downwind type is able to work as a passive yaw mechanism by itself. Although an efficiency of the downwind rotor is slightly less than of the upwind rotor, the downwind rotor does not need to equip any tail fin for working as a yaw control system. Therefore, if an efficiency of upwind and downwind rotor is likely to be similar, the downwind rotor should be better choice. The purpose of this study is to examine and compare an efficiency of upwind and downwind Thai ...

Wind energy, being easily accessible, environmentally friendly, and being cost effectively, has become the world’s one of popular growing renewable energy sources of electricity generation. Among all of the wind turbines, Horizontal Axis Wind Turbine (HAWT) is considered as leading technology due to its high efficiency. However, to spread this technology to mankind it is needed to develop turbine in this way that people can use it individually and comfortably. This kind of thinking accelerates the advancement of integration of wind turbine with Nano grid concept. Although great progress has been achieved in the wind technology, there is still scope to reduce the cost and improve the performance of small-scale wind turbines. Moreover, low wind velocity should also need to be utilized properly to achieve saturated energy production. So, concentration is going to small scale wind. Small scale horizontal axis wind turbines (SSHAWT) provide a clean, prospective and viable option for ener...

In this paper, a calibrated blade-element/momentum theory aerodynamic model of the MARIN stock wind turbine is developed and documented. The model is created using open-source software and calibrated to closely emulate experimental data obtained by the DeepCwind Consortium using a genetic algorithm optimization routine. The provided model will be useful for those interested in validating interested in validating floating wind turbine numerical simulators that rely on experiments utilizing the MARIN stock wind turbine—for example, the International Energy Agency Wind Task 30’s Offshore Code Comparison Collaboration Continued, with Correlation project.

Energy shortage issue is becoming critical day by day in rural areas. In order to fulfill basic energy needs i.e. to run 6 watt, 3 LED bulbs, charging of mobile phones, or running other electronic devices like radio, in rural area, 50 Watt is sufficient energy. In this study work design of small wind turbine blades is done by using blade element theory. The main features of this wind turbine is, ultralow cost. Its efficiency is up to 36%, which is high in small wind turbine category.

The all-time interest to increase turbomachinery efficiencies and pressure ratios has led to the progression of more robust and accurate simulation methods and tools. Even though 3-D CFD analyses are highly detailed and despite the computational power nowadays, they can be costly in terms of time and resources. Conversely, 2-D SLC methods provide acceptable performance and flow field results in short times. Because of economical and practical reasons, SLC still represents the cornerstone for turbomachinery design. In the present, the knowledge demand from the academia community in the airbreathing engine field has been expanding year after year. Nevertheless, there are very few open-source turbomachinery solvers that can be accessed, where user needs to know at least the basics of the programming language syntax and familiarize with it. For these reasons, a GUI was developed for an existing in-house 2-D SLC axial-flow compressor performance code, called SOCRATES. A GUI in this conte...

A detailed review of the current state-of-art for wind turbine blade design is presented, including theoretical maximum efficiency, propulsion, practical efficiency, HAWT blade design, and blade loads. The review provides a complete picture of wind turbine blade design and shows the dominance of modern turbines almost exclusive use of horizontal axis rotors. The aerodynamic design principles for a modern wind turbine blade are detailed, including blade plan shape/quantity, aerofoil selection and optimal attack angles. A detailed review of design loads on wind turbine blades is offered, describing aerodynamic, gravitational, centrifugal, gyroscopic and operational conditions.

The present work describes a method for the structural optimization of wind turbine rotor blades for given prescribed aerodynamic shape. The proposed approach operates at various description levels producing cost-minimizing solutions that satisfy desired design constraints at the finest modeling level. At first, a "coarse"-level constrained design optimization is performed by using a 1D spatial geometrically exact beam model for aeroservo-elastic multibody analysis and load calculation, integrated with a 2D FEM cross sectional model for stress/strain analysis, and the evaluation of the 1D model fully-populated cross sectional stiffness matrices. Next, a "fine"-level 3D FEM model is used for the refinement of the coarse-level solution. Improved results obtained at the level of the 3D model are utilized at the following coarse-level iteration through a heuristic modification of the design constraints. In addition, a buckling analysis is performed at the fine description level, which in turn affects the nonstructural blade mass. The updated constraint bounds and mass make their effects felt at the next coarse-level constrained design optimization, thereby closing the loop between the coarse and fine description levels. The multilevel optimization procedure is implemented in a computer program and it is demonstrated on the design of a multi-MW horizontal axis wind turbine rotor blade.

Wind energy, being easily accessible, environmentally friendly, and being cost effectively, has become the world's one of popular growing renewable energy sources of electricity generation. Among all of the wind turbines, Horizontal Axis Wind Turbine (HAWT) is considered as leading technology due to its high efficiency. However, to spread this technology to mankind it is needed to develop turbine in this way that people can use it individually and comfortably. This kind of thinking accelerates the advancement of integration of wind turbine with Nano grid concept. Although great progress has been achieved in the wind technology, there is still scope to reduce the cost and improve the performance of small-scale wind turbines. Moreover, low wind velocity should also need to be utilized properly to achieve saturated energy production. So, concentration is going to small scale wind. Small scale horizontal axis wind turbines (SSHAWT) provide a clean, prospective and viable option for energy supply. Moreover, SSHAWT can also be acted as one of the reliable power sources of Nano grid. To design efficient wind turbine it is required a smooth and continuous development process. The current study focused on aerodynamic design and performance analysis of small-scale horizontal axis wind turbine blade using the blade element momentum (BEM) method with most updated and corrected model. The effects of the design parameters of a small wind turbine such as the blade chord and twist angle distributions on power performance were also investigated. In this study, the pitch is fixed and speed is variable. Results show that the maximum coefficient of performance is .5089 at the Tip speed ratio 6.5 which is very indication in preliminary stage power prediction.

Unmanned aerial vehicles, UAV, has increases in the drastically in these past several years since their costs reduced. This research is based and built upon previous research presented in a conference. With the advent of commercial Quadcopters, four propeller systems, are used, being designed and used to operate the advantages of both flight and hovering. The basic design of their propeller blades has not evolved from the early days of manned flight when wooden fixed blades were used. In this paper that expands upon previous findings and discussions it explores the historical developments. Furthermore, how the expansion and reduction in costs of modern materials and manufacturing techniques that offer more accurate matching of blades' needs and applications.

A detailed review of the current state-of-art for wind turbine blade design is presented, including theoretical maximum efficiency, propulsion, practical efficiency, HAWT blade design, and blade loads. The review provides a complete picture of wind turbine blade design and shows the dominance of modern turbines almost exclusive use of horizontal axis rotors. The aerodynamic design principles for a modern wind turbine blade are detailed, including blade plan shape/quantity, aerofoil selection and optimal attack angles. A detailed review of design loads on wind turbine blades is offered, describing aerodynamic, gravitational, centrifugal, gyroscopic and operational conditions.

The all-time interest to increase turbomachinery efficiencies and pressure ratios has led to the progression of more robust and accurate simulation methods and tools. Even though 3-D CFD analyses are highly detailed and despite the computational power nowadays, they can be costly in terms of time and resources. Conversely, 2-D SLC methods provide acceptable performance and flow field results in short times. Because of economical and practical reasons, SLC still represents the cornerstone for turbomachinery design. In the present, the knowledge demand from the academia community in the airbreathing engine field has been expanding year after year. Nevertheless, there are very few open-source turbomachinery solvers that can be accessed, where user needs to know at least the basics of the programming language syntax and familiarize with it. For these reasons, a GUI was developed for an existing in-house 2-D SLC axial-flow compressor performance code, called SOCRATES. A GUI in this context supports as a teaching mechanism to explain not only the method itself, but also the compressor aerodynamic behaviour. The SOCRATES GUI consists in the axial-flow compressor model setup, solution and visualization for geometry and results. This paper outlines the main features of the 2-D SLC GUI, and uses a two-stage fan to show the flow field parameters and compressor/fan map, showing a consistent agreement against measured data.

Turbin Angin dapat menjadi salah satu solusi alat pembangkit tenaga listrik dengan mengkonversi energi angin menjadi listrik ditengah krisis energi global pada abad ke-21 ini. Kebutuhan energi didaerah perkotaan terus meningkat seiring berjalannya waktu yang tidak diikuti perkembangan sumber energi terbarukan. Dengan adanya gedung-gedung tinggi, semestinya meningkatkan potensi energi angin yang melewati sela-sela gedung yang merupakan konsentrator angin. Maka, perlu dirancang Propeler Turbin Angin yang optimal yang dapat menjawab kebutuhan energi di daerah perkotaan khususnya pada Gedung Hemat Energi yang sengaja dirancang khusus untuk memusatkan aliran angin.Penelitian ini bertujuan untuk mendapatkan parameter-parameter disain untuk turbin angin poros horisontal yang meliputi rotor radius, chord length, dan twist dengan menggunakan metoda Blade Element Momentum. Coefficient of Performance (CP) dari perhitungan dibandingkan terhadap berbagai Tip Speed Ratio (TSR) serta perubahan profil blade baik secara linearisasi maupun mengganti komposisi dan konfigurasi airfoil yang akan digunakan. Nilai TSR yang digunakan adalah TSR 4 hingga TSR 10.Berdasarkan hasil penelitian, konfigurasi yang menghasilkan CP terbaik adalah Mixed Ideal Blade dengan nilai 47.6% pada TSR 8. Dari hasil penelitian tersebut, maka Mixed Ideal Blade dapat diaplikasikan pada Gedung Hemat Energi di daerah perkotaan.

Turbin angin dapat menjadi salah satu solusi alat pembangkit tenaga listrik dengan mengkonversi energi angin menjadi listrik ditengah krisis energi global pada abad ke-21 ini. Kebutuhan energi didaerah perkotaan terus meningkat seiring berjalannya waktu yang tidak diikuti perkembangan sumber energi terbarukan. Dengan adanya gedung-gedung tinggi, semestinya meningkatkan potensi energi angin yang melewati sela-sela gedung yang merupakan konsentrator angin. Maka, perlu dirancang Propeler Turbin Angin yang optimal yang dapat menjawab kebutuhan energi di daerah perkotaan khususnya pada Gedung Hemat Energi. Penelitian ini bertujuan untuk mengetahui desain propeler yang paling optimum. Penelitian dilakukan dengan proses perhitungan

A detailed review of the current state-of-art for wind turbine blade design is presented, including theoretical maximum efficiency, propulsion, practical efficiency, HAWT blade design, and blade loads. The review provides a complete picture of wind turbine blade design and shows the dominance of modern turbines almost exclusive use of horizontal axis rotors. The aerodynamic design principles for a modern wind turbine blade are detailed, including blade plan shape/quantity, aerofoil selection and optimal attack angles. A detailed review of design loads on wind turbine blades is offered, describing aerodynamic, gravitational, centrifugal, gyroscopic and operational conditions.

A detailed review of the current state-of-art for wind turbine blade design is presented, including theoretical maximum efficiency, propulsion, practical efficiency, HAWT blade design, and blade loads. The review provides a complete picture of wind turbine blade design and shows the dominance of modern turbines almost exclusive use of horizontal axis rotors. The aerodynamic design principles for a modern wind turbine blade are detailed, including blade plan shape/quantity, aerofoil selection and optimal attack angles. A detailed review of design loads on wind turbine blades is offered, describing aerodynamic, gravitational, centrifugal, gyroscopic and operational conditions.

In order to study the applicability of different turbulence models in the prediction of propeller hydrodynamic performance, computational fluid dynamics software CFX was used to simulate the thrust coefficient, torque coefficient and efficiency of VP1304 propeller under specific viscous flow field conditions by using -k models, -k models, SST models and RSM models respectively. The prediction results from the four turbulence models are compared with the experimental data of controlled pitch propeller VP1304 published by SVA Potsdam. It is concluded that the simulation prediction of performance due to the RSM model is the most accurate, Merits and demerits of RSM model is analyzed.

In hydropower systems among hydropower plants there are storage pump units. In order to ensure higher flow rate, the pumps have constructive differences besides regular. Consequently, the complex shape of the suction-elbow with symmetric inlet generates an unsteady flow which is ingested by impeller. These phenomena also generate stronger unsteady flow conditions, such as stall, wakes, turbulence and pressure fluctuations, which affect the overall mechanical behaviour of the pump with vibration, noise and radial and axial forces on the rotor. Alternatively, an axial rotor can be installed in front of the impeller. In this case, the nonuniformity flow will be decreased, and the static pressure will be increased at the impeller inlet. Consequently, the efficiency behaviour practically remains unchanged while the cavitational behaviour is improved. The paper investigates experimentally a pump system with the axial rotor having variable speed, while the pump impeller has constant speed. First, the paper presents the experimental test rig, the control and acquisition system. Second, is presented the pump system equipped with the clutch in order to have variable speed for the axial rotor. Thirdly, the experimental results concentrate on the axial rotor influence on the efficiency behaviour. The last section draws the conclusions.

A strategy of urban sewage centralized management is implemented in the most cities (e.g. Timisoara). All wastewater is collected and conveyed to a central location for treatment or disposal. In the urban area, the rainwater is embedded in the wastewater management. Seven rainwater pumps are installed in a wastewater treatment plant to protect it against flooding. This type of pumps is vertically installed in Timisoara's wastewater treatment plant in order to pump the additional rainwater protecting it. Several catastrophic events have been occurred at the rainwater pumps tacking them out of service after a limited operation time. The fastening bolts of the blades are brittle broken due to the clog of the impeller with waste rag balls. The cumulated operation time is examined for each rainwater pump together with the catastrophic events identified in service. The mechanical properties of the waste fibres are experimentally determined with respect to it area in order to assess the clog/rag conditions corresponding to the clearance between the impeller blades and housing. Next, the inertial torque associated to the rotating parts of the rainwater pump is estimated to check the level when sudden locking occurs due to the impeller clogging. The maximum stress level of the fastening bolts is exceeded when the impeller is partially clogged or ragged. As a result, the root cause of the problem is associated with the ragging level of the impeller. A solution is proposed to avoid these problems.

The past decade has experienced a boom in industries and engineering. This has led to an increase in demand for power. The major power generators are wind farms, thermal power plants and hydroelectric power plants. All these industries employ a common method of harnessing power-Turbines. The efficiency of these turbines can be improved by reducing the material used or by increasing the longevity of the blades by either changing the chord length or the twist angle of the turbine blades. Based on the applications of the turbine, these blades have different geometries i.e. different airfoils, different chord lengths and different degrees of twists. The current paper attempts to analyze the effect of chord length and angle of twist on the von-mises stress distribution over the wing of a thin airfoil, namely NACA 5504 using finite element methods. The blade is assumed to be made of aluminum material.

The article is devoted to the consideration of a new design of a wind power plant, improved in comparison with known samples, which can be used for the industrial production of electrical energy. The design is distinguished by the presence of two wind wheels, high efficiency and environmental friendliness.

Turbin angin dapat menjadi salah satu solusi alat pembangkit tenaga listrik dengan mengkonversi energi angin menjadi listrik ditengah krisis energi global pada abad ke-21 ini. Kebutuhan energi didaerah perkotaan terus meningkat seiring berjalannya waktu yang tidak diikuti perkembangan sumber energi terbarukan. Dengan adanya gedung-gedung tinggi, semestinya meningkatkan potensi energi angin yang melewati sela-sela gedung yang merupakan konsentrator angin. Maka, perlu dirancang Propeler Turbin Angin yang optimal yang dapat menjawab kebutuhan energi di daerah perkotaan khususnya pada Gedung Hemat Energi. Penelitian ini bertujuan untuk mengetahui desain propeler yang paling optimum. Penelitian dilakukan dengan proses perhitungan

A detailed review of the current state-of-art for wind turbine blade design is presented, including theoretical maximum efficiency, propulsion, practical efficiency, HAWT blade design, and blade loads. The review provides a complete picture of wind turbine blade design and shows the dominance of modern turbines almost exclusive use of horizontal axis rotors. The aerodynamic design principles for a modern wind turbine blade are detailed, including blade plan shape/quantity, aerofoil selection and optimal attack angles. A detailed review of design loads on wind turbine blades is offered, describing aerodynamic, gravitational, centrifugal, gyroscopic and operational conditions.

A detailed review of the current state-of-art for wind turbine blade design is presented, including theoretical maximum efficiency, propulsion, practical efficiency, HAWT blade design, and blade loads. The review provides a complete picture of wind turbine blade design and shows the dominance of modern turbines almost exclusive use of horizontal axis rotors. The aerodynamic design principles for a modern wind turbine blade are detailed, including blade plan shape/quantity, aerofoil selection and optimal attack angles. A detailed review of design loads on wind turbine blades is offered, describing aerodynamic, gravitational, centrifugal, gyroscopic and operational conditions.

A detailed review of the current state-of-art for wind turbine blade design is presented, including theoretical maximum efficiency, propulsion, practical efficiency, HAWT blade design, and blade loads. The review provides a complete picture of wind turbine blade design and shows the dominance of modern turbines almost exclusive use of horizontal axis rotors. The aerodynamic design principles for a modern wind turbine blade are detailed, including blade plan shape/quantity, aerofoil selection and optimal attack angles. A detailed review of design loads on wind turbine blades is offered, describing aerodynamic, gravitational, centrifugal, gyroscopic and operational conditions.

Axial fans are one of the most harmful sources of noise due to their close proximity to occupied areas and widespread use. The prolonged exposure to hazardous noise levels can lead to noise-induced hearing loss. Consequently, there is a critical need to reduce noise levels from ventilation fans. Since fan noise scales with the 4-6th power of the fan tip speed, minimizing the fan tip speed is an effective method to reduce fan noise. However, reducing the fan speed results in a decrease in aerodynamic performance. To this end, the present study uses multi-element airfoils to increase the aerodynamic characteristics of the fan blades to enable lower fan speeds and noise relative to fan blades with single element airfoils. Additionally, a control vortex design method has been implemented to increase the effectiveness of the blade outer sections, i.e. spanwise varying axial flow. The resulting blade geometry has been shown to reduce noise levels while maintaining the same volumetric flow...

In this study, an off-grid–type small wind turbine for street lighting was designed and analyzed. Its performance was predicted using a computational fluid dynamics model. The proposed wind turbine has two blades with a radius of 0.29 m and a height of 1.30 m. Ansys Fluent, a commercial computational fluid dynamics solver, was used to predict the performance, and the k-omega SST model was used as the turbulence model. The simulation result revealed a tip-speed ratio of 0.54 with a maximum power coefficient, or an aerodynamic rotor efficiency of 0.17. A wind turbine was installed at a measurement site to validate the simulation, and a performance test was used to measure the power production. To compare the simulation results obtained from the CFD simulation with the measured electrical power performance, the efficiencies of the generator and the controller were measured using a motor-generator testbed. Also, the control strategy of the controller was found from the field test and ap...

Turbin angin dapat menjadi salah satu solusi alat pembangkit tenaga listrik dengan mengkonversi energi angin menjadi listrik ditengah krisis energi global pada abad ke-21 ini. Kebutuhan energi didaerah perkotaan terus meningkat seiring berjalannya waktu yang tidak diikuti perkembangan sumber energi terbarukan. Dengan adanya gedung-gedung tinggi, semestinya meningkatkan potensi energi angin yang melewati sela-sela gedung yang merupakan konsentrator angin. Maka, perlu dirancang Propeler Turbin Angin yang optimal yang dapat menjawab kebutuhan energi di daerah perkotaan khususnya pada Gedung Hemat Energi. Penelitian ini bertujuan untuk mengetahui desain propeler yang paling optimum. Penelitian dilakukan dengan proses perhitungan

Turbin Angin dapat menjadi salah satu solusi alat pembangkit tenaga listrik dengan mengkonversi energi angin menjadi listrik ditengah krisis energi global pada abad ke-21 ini. Kebutuhan energi didaerah perkotaan terus meningkat seiring berjalannya waktu yang tidak diikuti perkembangan sumber energi terbarukan. Dengan adanya gedung-gedung tinggi, semestinya meningkatkan potensi energi angin yang melewati sela-sela gedung yang merupakan konsentrator angin. Maka, perlu dirancang Propeler Turbin Angin yang optimal yang dapat menjawab kebutuhan energi di daerah perkotaan khususnya pada Gedung Hemat Energi yang sengaja dirancang khusus untuk memusatkan aliran angin.Penelitian ini bertujuan untuk mendapatkan parameter-parameter disain untuk turbin angin poros horisontal yang meliputi rotor radius, chord length, dan twist dengan menggunakan metoda Blade Element Momentum. Coefficient of Performance (CP) dari perhitungan dibandingkan terhadap berbagai Tip Speed Ratio (TSR) serta perubahan profil blade baik secara linearisasi maupun mengganti komposisi dan konfigurasi airfoil yang akan digunakan. Nilai TSR yang digunakan adalah TSR 4 hingga TSR 10.Berdasarkan hasil penelitian, konfigurasi yang menghasilkan CP terbaik adalah Mixed Ideal Blade dengan nilai 47.6% pada TSR 8. Dari hasil penelitian tersebut, maka Mixed Ideal Blade dapat diaplikasikan pada Gedung Hemat Energi di daerah perkotaan.

A detailed review of the current state-of-art for wind turbine blade design is presented, including theoretical maximum efficiency, propulsion, practical efficiency, HAWT blade design, and blade loads. The review provides a complete picture of wind turbine blade design and shows the dominance of modern turbines almost exclusive use of horizontal axis rotors. The aerodynamic design principles for a modern wind turbine blade are detailed, including blade plan shape/quantity, aerofoil selection and optimal attack angles. A detailed review of design loads on wind turbine blades is offered, describing aerodynamic, gravitational, centrifugal, gyroscopic and operational conditions.

A detailed review of the current state-of-art for wind turbine blade design is presented, including theoretical maximum efficiency, propulsion, practical efficiency, HAWT blade design, and blade loads. The review provides a complete picture of wind turbine blade design and shows the dominance of modern turbines almost exclusive use of horizontal axis rotors. The aerodynamic design principles for a modern wind turbine blade are detailed, including blade plan shape/quantity, aerofoil selection and optimal attack angles. A detailed review of design loads on wind turbine blades is offered, describing aerodynamic, gravitational, centrifugal, gyroscopic and operational conditions.

A detailed review of the current state-of-art for wind turbine blade design is presented, including theoretical maximum efficiency, propulsion, practical efficiency, HAWT blade design, and blade loads. The review provides a complete picture of wind turbine blade design and shows the dominance of modern turbines almost exclusive use of horizontal axis rotors. The aerodynamic design principles for a modern wind turbine blade are detailed, including blade plan shape/quantity, aerofoil selection and optimal attack angles. A detailed review of design loads on wind turbine blades is offered, describing aerodynamic, gravitational, centrifugal, gyroscopic and operational conditions.

In this paper we present a dynamical systems model and control algorithms for a small, vertical axis wind turbine (VAWT). The wind turbine is designed for the domestic market, including regions without very favorable wind conditions. Good performance at low wind speeds is an important requirement for developing an economically viable, suburban VAWT. The performance of a VAWT can be greatly enhanced by incorporating estimation and control capabilities. Individual blade pitch and camber controls are considered in our VAWT design. Pitch control is achieved by rotating each individual blade about its vertical axis, while camber control is realized using a trailing edge flap on each blade. Using camber and pitch controls help in creating a greater force differential across the turbine than using pitch control alone. In this paper we present a simple strategy for implementing pitch control and demonstrate the resulting efficiency improvement through a simulation.

Pumps are used in a variety of important applications. Often, the pipe characteristic is unsatisfactory known and the selected pump has more power than needed. It will thus be throttled or the flow is throttled during operation. In such cases the pump operates under part-load flow and the inflow condition differs from the dimensioning point. In this paper results for

Mulu Bayray School of Mechanical and Industrial Engineering, Ethiopian Institute of TechnologyMekelle, Mekelle University, Mekelle, Ethiopia mul_at@yahoo.com Abstract—The aim of this paper is to foster wind turbine blade design optimization using Genetic Algorithm considering NACA64A410 as a case. The design optimization of turbine blades using GA with regards to different objective functions are described and found supportive one another. NACA64A410 aerofoil shape is modeled as baseline aerofoil using fifth order Bezier curve functions with acceptable error to find control points that to shape of the aerofoil. Design of Experiment is planned for eight design variables with three levels each. 27 analyses are conducted with a varying control point values using ANSYS Fluent 14.0 workbench. Lift and drag coefficients are recorded as an output for each analyses. The objective function is formulated as a minimization problem of drag-to-lift coefficient ratio subjected to bounded constrai...

This paper presents a cooperative control to optimize the total wind-farm power efficiency by obtaining the power production of each single wind turbine. The aim of this study is to maximize the total power production. The production efficiency of a single and multi-wind turbines using optimal effective method is investigated. The production of power and the loading for a wind turbine can be obtained by finding out the pitch angles, nacelle system control and generator factors. The optimization issue is related to the point of maximizing the sum of the production of power for a wind farm. The optimal combination of the induction factors and yaw offset angles is obtained by applying a steepest descent algorithm. The contribution of this study is to control and apply optimal values of wind turbines for maximizing wind farm power production using wake control system. The results show that the cooperative control system approach can increase the power production in wind farm.

In this paper, an investigation of the dynamic effects of the low-amplitude, high-frequency excitation of a composite aerofoil by means of integrated actuators on the flow is presented. For this purpose, a well-established elastic NACA 64-418 profile was manufactured from a glass fibre reinforced epoxy resin with integrated active elements. The modal properties of the profile were optimized during the design process in such a way that the spatial distribution of nodes and antinodes of the profile is potentially advantageous for the influence of the flow behaviour around the profile. Additionally, the respective eigenfrequency of the profile should be high enough to efficiently influence the flow. The first numerical and experimental results confirm that the aimed modal properties could be obtained. The optimized profile design has been implemented in the resin transfer moulding manufacturing process and selected low-profile actuating elements were applied after fibre-reinforced plas...

A detailed review of the current state-of-art for wind turbine blade design is presented, including theoretical maximum efficiency, propulsion, practical efficiency, HAWT blade design, and blade loads. The review provides a complete picture of wind turbine blade design and shows the dominance of modern turbines almost exclusive use of horizontal axis rotors. The aerodynamic design principles for a modern wind turbine blade are detailed, including blade plan shape/quantity, aerofoil selection and optimal attack angles. A detailed review of design loads on wind turbine blades is offered, describing aerodynamic, gravitational, centrifugal, gyroscopic and operational conditions.

Wind energy is the kinetic energy associated with movement of large masses of air. These motions result from uneven heating of atmosphere by sun creating temperature, density, pressure differences. It is an indirect form of solar energy The device used to convert kinetic energy of wind into electrical power is called a wind turbine. Vertical Axis wind power generators, represent a very promising future for wind power generation. In present study an attempt is made to utilize at low velocity wind below 4m/s for useful power generation using magnetic levitation for vertical axis wind turbine (VAWT) termed as Maglev turbine. A single large Maglev turbine can give output more than conventional horizontal axis wind turbine (HAWT). The rotor that is designed to harness enough air to rotate the shaft at low and high wind speeds while keeping the centre of mass closer to the base of yielding stability due to Maglev effect. The efficiency of turbine is increased by replacing the conventional...

In order to obtain higher propulsion efficiency for marine transportation, the authors have numerically tested a novel trochoidal propeller using a sinusoidal blade pitch function. The main results presented here are the evaluation of thrust and torque, as well as the calculated hydrodynamic efficiency, for various absolute advance coefficients. The performance of the present sinusoidal-pitch trochoidal propeller is compared with previous analytical calculations of transverse propeller performances. Calculations for the trochoidal propeller are performed using a two-dimensional model. The numerical calculation is used to optimize the foil pitch function in order to achieve the highest efficiency for a given geometry and operational parameters. Foil-to-foil interactions are also studied for multiple-foil propellers to determine the effects of the blade number on the hydrodynamic efficiency.

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...

Within wind energy research there is a drive towards the development of a "smart rotor"; a rotor of which the loading can be measured and controlled through the application of a sensor system, a control system and an aerodynamic device. Most promising solutions from an aerodynamic point of view are trailing edge flaps, either hinged or continuously deformable. An experiment was considered necessary in which the effectiveness of such a system, with the interaction between dynamics, aerodynamics and control was tested. In order to perform this experiment, a blade needed to be constructed that had the scaled dynamics of a full scale blade as well as sufficient actuation power and sensors for measurements as well as feedback control. A blade was designed and tested with sufficient strength for high wind speed as well as an eigenfrequency (12.5Hz) that was close to the initial value (19.2Hz), derived from scaling the dynamics. Finally adapting the airspeed set the right dynamics. System identification was performed and a controller designed with which a significant reduction in vibrations was attained.

Numerical analysis was carried out to investigate the influence of the setting angle and chord length on the pressure distribution especially for the shroud span of an axial fan. The setting angle was referred to as AOA (angle of attack). The aerodynamic performance of an axial fan with the change of setting angle and chord length was presented, and the unstable pressure distribution was discussed in detail. The airfoil of an axial fan was based on the NACA 3512. The influence of the setting angle was observed with the designed sets which were rotated based on the center of gravity for the blade. The chord length was adjusted while maintaining the setting angle. For each design parameter, 5 sets were designed to conduct the single-factor analysis, respectively. The setting angle had a sensitive effect on the aerodynamic performance of an axial fan. The pressure distribution became unstable related to the setting angle of the shroud span. On the other hand, the chord length was only proportional to the pressure rise and had a little effect on efficiency.

This paper presents the effect of blade thickness on the hydraulic performance of a mixed-flow pump impeller. For the numerical analysis, three-dimensional steady-state Reynolds-averaged Navier-Stokes (RANS) equations are discretized using the finite volume method with the shear stress transport (SST) turbulence model. The equations were solved using hexahedral grids to analyze the internal flow in the mixed-flow pump impeller. The blockage concept is employed to express the quantitative amount by the variation in the blade thickness. The effects of hydraulic performance on the blockage amount are systematically analyzed with the variation in the best efficiency point (BEP) in the performance curve. The detailed flow characteristics with the blockage effect are analyzed and discussed.

The paper studies the applicability of the IEC 61400-1 ed.3, 2005 International Standard of wind turbine minimum design requirements in the case of an onshore Darrieus VAWT and compares the results of basic Design Load Cases (DLCs) with those of a 3-bladed HAWT. The study is based on aeroelastic computations using the HAWC2 aero-servo-elastic code A 2-bladed 5 MW VAWT rotor is used based on a modified version of the DeepWind rotor For the HAWT simulations the NREL 3-bladed 5 MW reference wind turbine model is utilized Various DLCs are examined including normal power production, emergency shut down and parked situations, from cut-in to cutout and extreme wind conditions. The ultimate and 1 Hz equivalent fatigue loads of the blade root and turbine base bottom are extracted and compared in order to give an insight of the load levels between the two concepts. According to the analysis the IEC 61400-1 ed.3 can be used to a large extent with proper interpretation of the DLCs and choice of parameters such as the hub-height. In addition, the design drivers for the VAWT appear to differ from the ones of the HAWT. Normal operation results in the highest tower bottom and blade root loads for the VAWT, where parked under storm situation (DLC 6.2) and extreme operating gust (DLC 2.3) are more severe for the HAWT. Turbine base bottom and blade root edgewise fatigue loads are much higher for the VAWT compared to the HAWT. The interpretation and simulation of DLC 6.2 for the VAWT lead to blade instabilities, while extreme wind shear and extreme wind direction change are not critical in terms of loading of the VAWT structure. Finally, the extreme operating gust wind condition simulations revealed that the emerging loads depend on the combination of the rotor orientation and the time stamp that the frontal passage of gust goes through the rotor plane.

Axial flow fans installed at large-scale air-cooled condensers (ACCs) may operate under distorted inlet air flow conditions. These inflow conditions as well as the fan’s surroundings cause a variation in blade loading as a function of the blade’s rotational position. An investigation was launched to simultaneously measure the inlet air flow and the resultant blade and gearbox loading conditions of a single fan located on the edge of a large-scale ACC. Measurements were recorded over a period of five days where it was found that the air flow through the fan is highly dependent on the wind speed and direction. Subsequently, the pressure rise over the fan, which affects the blade loading, is highly dependent on the atmospheric wind speed and direction as well. In addition, the fan blade was found to vibrate at its own natural frequency of approximately 6 Hz when excited by the aerodynamic loading.

Electricity production must shift towards carbon neutral sources such as wind power to mitigate the impacts of climate change. Wind energy today accounts 18.8% of total installed power generation capacity in Europe, with a total installed capacity of 189 GW (170 GW onshore and 19 GW offshore wind farms), taking the second largest form of power generation capacity, closely approaching gas installed capacity. The progress of wind turbine technology over the last 20 years is important and is also the main reason for the rapid development of the wind power globally. In addition, the nominal capacity of onshore wind turbines has increased to more than 3 MW and more than 5 MW for offshore wind turbines. Despite the tendency for larger wind turbines there is a significant potential for small wind turbines for the urban environment as well as for off grid applications. The objective of this work is to provide a spherical knowledge of the technology of small wind turbines in the range of some kW up to 50kW nominal capacity, their market, costs, as well as their possible applications in urban and in off grid environment. Parameters such as, performance, noise issues, and visual disturbance is also discussed in this paper.

A detailed review of the current state-of-art for wind turbine blade design is presented, including theoretical maximum efficiency, propulsion, practical efficiency, HAWT blade design, and blade loads. The review provides a complete picture of wind turbine blade design and shows the dominance of modern turbines almost exclusive use of horizontal axis rotors. The aerodynamic design principles for a modern wind turbine blade are detailed, including blade plan shape/quantity, aerofoil selection and optimal attack angles. A detailed review of design loads on wind turbine blades is offered, describing aerodynamic, gravitational, centrifugal, gyroscopic and operational conditions.

The search for more efficient and sustainable renewable energies is rapidly growing. Throughout the years, wind turbines matured towards a lowered cost-of-energy and have grown in rotor size therefore stretched the role of composite materials that offered the solution to more flexible, lighter and stronger blades. The objective of this paper is to present an improved version of the preliminary optimization tool called Co-Blade, which will offer designers and engineers an accelerated design phase by providing the capabilities to rapidly evaluate alternative composite layups and study their effects on static failure and fatigue of wind turbine blades. In this study, the optimization formulations include non-linear failure constraints. In addition a comparison between 3 formulations is made to show the importance of choosing the blade mass as the main objective function and the inclusion of failure constraints in the wind turbine blade design.

A detailed review of the current state-of-art for wind turbine blade design is presented, including theoretical maximum efficiency, propulsion, practical efficiency, HAWT blade design, and blade loads. The review provides a complete picture of wind turbine blade design and shows the dominance of modern turbines almost exclusive use of horizontal axis rotors. The aerodynamic design principles for a modern wind turbine blade are detailed, including blade plan shape/quantity, aerofoil selection and optimal attack angles. A detailed review of design loads on wind turbine blades is offered, describing aerodynamic, gravitational, centrifugal, gyroscopic and operational conditions.

This article investigates the impact of the pitch-to-stall and pitch-to-feather control concepts on horizontal axis wind turbines (HAWTs) with different blade designs. Pitch-to-feather control is widely used to limit the power output of wind turbines in high wind speed conditions. However, stall control has not been taken forward in the industry because of the low predictability of stalled rotor aerodynamics. Despite this drawback, this article investigates the possible advantages of this control concept when compared to pitch-to-feather control with an emphasis on the control performance and its impact on the pitch mechanism and structural loads. In this study, three HAWTs with different blade designs, i.e., untwisted, stall-regulated, and pitch-regulated blades, are investigated. The control system is validated in both uniform and turbulent wind speed. The results show that pitch-to-stall control enhances the constant power control for wind turbines with untwisted and stall-regulated blade designs. Stall control alleviates the fore-aft tower loading and the blades flapwise moment of the wind turbine with stall-regulated blades in uniform winds. However, in turbulent winds, the flapwise moment increases to a certain extent as compared to pitch-to-feather control. Moreover, pitch-to-stall control considerably reduces the summed blade pitch movement, despite that it increases the risk of surface damage in the rolling bearings due to oscillating movements with a small amplitude.