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Aerodynamic Pressure And Flow Visualization Measurement From A Rotating Wind Turbine Blade
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Book Synopsis Aerodynamic Pressure and Flow-visualization Measurement from a Rotating Wind Turbine Blade by : Charles P. Butterfield
Download or read book Aerodynamic Pressure and Flow-visualization Measurement from a Rotating Wind Turbine Blade written by Charles P. Butterfield and published by . This book was released on 1988 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Aerodynamic Pressure and Flow-visualization Measurement from a Rotating Wind Turbine Blade by :
Download or read book Aerodynamic Pressure and Flow-visualization Measurement from a Rotating Wind Turbine Blade written by and published by . This book was released on 1988 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Aerodynamic, load, flow-visualization, and inflow measurements have been made on a 10-m, three-bladed, downwind, horizontal-axis wind turbine (HAWT). A video camera mounted on the rotor was used to record nighttime and daytime video images of tufts attached to the low-pressure side of a constant-chord, zero-twist blade. Load measurements were made using strain gages mounted at every 10% of the blade's span. Pressure measurements were made at 80% of the blade's span. Pressure taps were located at 32 chordwise positions, revealing pressure distributions comparable with wind tunnel data. Inflow was measured using a vertical-plane array of eight propvane and five triaxial (U-V-W) prop-type anemometers located 10 m upwind in the predominant wind direction. One objective of this comprehensive research program was to study the effects of blade rotation on aerodynamic behavior below, near, and beyond stall. To this end, flow patterns are presented here that reveal the dynamic and steady behavior of flow conditions on the blade. Pressure distributions are compared to flow patterns and two-dimensional wind tunnel data. Separation boundary locations are shown that change as a function of spanwise location, pitch angle, and wind speed. 6 refs., 23 figs., 1 tab.
Book Synopsis Aerodynamic Testing of a Rotating Wind Turbine Blade by : C. P. Butterfield
Download or read book Aerodynamic Testing of a Rotating Wind Turbine Blade written by C. P. Butterfield and published by . This book was released on 1990 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Aerodynamic, load, flow-visualization, and inflow measurements were taken on a downwind horizontal-axis wind turbine (HAWT). A video camera mounted on the rotor recorded video images of tufts attached to the low-pressure side of the blade. Strain gages, mounted every 10% of the blade's span, provided load and pressure measurements. Pressure taps at 32 chordwise positions recorded pressuredistributions. Wind inflow was measured via a vertical-plane array of anemometers located 10 m upwind. The objectives of the test were to address whether airfoil pressure distributions measured on a rotating blade differed from those measured in the wind tunnel, if radial flow near or in the boundary layer of the airfoil affected pressure distributions, if dynamic stall could result in increaseddynamic loads, and if the location of the separation boundary measured on the rotating blade agreed with that measured in two-dimensional flow in the wind tunnel.
Book Synopsis Aerodynamic Pressure Measurements on a Rotating Wind Turbine Blade by : Charles P. Butterfield
Download or read book Aerodynamic Pressure Measurements on a Rotating Wind Turbine Blade written by Charles P. Butterfield and published by . This book was released on 1990 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt: Wind turbine generators commonly operate in either a fixed-pitch or variable-pitch mode. In variable-pitch mode the angle of the blade is changed as the wind speed varies to maintain near optimum airfoil angle of attack and to regulate peak power. The more common fixed-pitch rotors do not change pitch angle to regulate peak power. Instead the blade is allowed to stall aerodynamically. This approach results in rapid relief of loads caused by gusts and is more reliable and cost effective. However, the designer must accurately understand the rotating-blade stall; behavior of the airfoil in order to predict turbine loads. To understand such stall behavior a test program that uses specially designed instrumentation has been conducted by the Solar Energy Research Institute (SERI). A microprocessor-controlled measurement system has been designed and built to make accurate measurements of low pressures on a rotating wind turbine blade.
Book Synopsis Introduction to Wind Turbine Aerodynamics by : A. P. Schaffarczyk
Download or read book Introduction to Wind Turbine Aerodynamics written by A. P. Schaffarczyk and published by Springer Nature. This book was released on 2020-02-28 with total page 315 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book offers an introduction to the topic for professionals and students with a diverse range of backgrounds. Wind Turbine Aerodynamics is a self-contained textbook that shows how to progress from the basics of fluid mechanics to modern wind turbine blade design. It presents the fundamentals of fluid dynamics and inflow conditions, as well as extensive information on theories describing the aerodynamics of wind turbines. After examining a number of related experiments, the book applies the lessons learned to blade design. The text of the 2nd edition has been thoroughly revised, with a focus on improved readability. The examples and solutions have been extended to explain each problem in much greater detail.
Book Synopsis Quantitative Measurement Techniques for Wind Turbine Blade Aerodynamic Performance by : Tyler Gallant
Download or read book Quantitative Measurement Techniques for Wind Turbine Blade Aerodynamic Performance written by Tyler Gallant and published by . This book was released on 2017 with total page 175 pages. Available in PDF, EPUB and Kindle. Book excerpt: The installed capacity of wind turbines has been growing rapidly in recent years, creating an increased need for accurate measurements and models of wind turbine performance to further their development. There is a need in the literature for experimental data to validate theoretical models and guide turbine blade design. Two related projects were completed to develop measurement techniques and provide such data: the use of a five-hole probe and in-blade data acquisition system to measure the wind turbine blade angle of attack, and the use of tuft flow visualization and a digital image processing algorithm to quantitatively assess the flow direction and behaviour of a wind turbine blade. Experiments were completed at the University of Waterloo Wind Generation Research Facility using a 3.3 m diameter test turbine. Wind speed, rotational speed, shaft torque and angular position were controlled or monitored throughout all experiments. A 3D printed test blade was equipped with a five-hole pressure probe and data acquisition system to measure the flow angles at various radial locations. For tuft flow visualization testing, a separate rotor consisting of three aerodynamic blades was installed, and tufts and a camera were mounted to the surface of one of the blades. Extensive software was developed for controlling instruments and collecting experimental data. The angle of attack and span-wise flow angles were successfully measured as a function of the tip speed ratio, yaw-offset position, radial location and azimuthal position. Variations in the angle of attack with these variables were consistent with wind turbine aerodynamics theory, and results were in close agreement with results calculated using two separate models from the literature. Angle of attack values typically ranged from 7° to 25° throughout the tests, with fluctuations as high as 7°when the wind turbine was yawed. Uncertainty values in the measurements were typically found to be within ±0.2°, which shows great potential for the method. Tuft flow visualization measurements were processed by logging the orientation of each individual tuft, calculating their average orientations and interpolating to develop a contour map of flow direction over the wind turbine blade as a function of tip speed ratio, yaw-position and azimuthal position. Throughout testing, the fraction of tufts indicating stall ranged from 25% to as high as 60% as the tip speed ratio was decreased. Contour maps showed that separation typically formed first on the trailing edge of the blade near the root, and expanded towards the leading edge and tip. This pattern is in agreement with trends found for similar blades in the literature.
Book Synopsis Aerodynamic Pressure Measurements on a Rotating Wind Turbine Blade by :
Download or read book Aerodynamic Pressure Measurements on a Rotating Wind Turbine Blade written by and published by . This book was released on 1990 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Wind turbine generators commonly operate in either a fixed-pitch or variable-pitch mode. In variable-pitch mode the angle of the blade is changed as the wind speed varies to maintain near optimum airfoil angle of attack and to regulate peak power. The more common fixed-pitch rotors do not change pitch angle to regulate peak power. Instead the blade is allowed to stall aerodynamically. This approach results in rapid relief of loads caused by gusts and is more reliable and cost effective. However, the designer must accurately understand the rotating-blade stall; behavior of the airfoil in order to predict turbine loads. To understand such stall behavior a test program that uses specially designed instrumentation has been conducted by the Solar Energy Research Institute (SERI). A microprocessor-controlled measurement system has been designed and built to make accurate measurements of low pressures on a rotating wind turbine blade.
Book Synopsis Three-dimensional Airfoil Performance Measurements on a Rotating Wing by :
Download or read book Three-dimensional Airfoil Performance Measurements on a Rotating Wing written by and published by . This book was released on 1989 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The objective of this comprehensive research program was to study the effects of horizontal-axis wind turbine (HAWT) blade rotation on aerodynamic behavior below, near, and beyond stall. This paper describes the flow angle sensor used to measure angle of attack (AOA) and how the sensor was calibrated, and it gives results of pressure integrations on the blade. Aerodynamic, load, flow-visualization, and inflow measurements were made on a 10-m, three-bladed, downwind HAWT. A video camera was mounted on the rotor to record video images of tufts attached to the low-pressure side of a constant-chord, zero-twist blade. Load measurements were made using strain gages mounted every 10% of the blade's span. Pressure taps were located at 32 chordwise positions and revealed pressure distributions comparable with wind tunnel data. Inflow was measured using a vertical-plane array of eight propvane and five triaxial (U-V-W) prop-type anemometers located 10 m upwind in the predominant wind direction. Results show evidence of stall hysteresis and unsteadiness at high AOA. Correlations with analytical predictions and wind tunnel tests show good agreement at low AOA and poor agreement at high AOA. 7 refs., 12 figs.
Book Synopsis Flow Visualization on a Rotating Wind Turbine Blade by : Chen Ming
Download or read book Flow Visualization on a Rotating Wind Turbine Blade written by Chen Ming and published by . This book was released on 1993 with total page 37 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Three-dimensional Airfoil Performance Measurements on a Rotating Wing by : Charles P. Butterfield
Download or read book Three-dimensional Airfoil Performance Measurements on a Rotating Wing written by Charles P. Butterfield and published by . This book was released on 1989 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The objective of this comprehensive research program was to study the effects of horizontal-axis wind turbine (HAWT) blade rotation on aerodynamic behavior below, near, and beyond stall. This paper describes the flow angle sensor used to measure angle of attack (AOA) and how the sensor was calibrated, and it gives results of pressure integrations on the blade. Aerodynamic, load, flow-visualization, and inflow measurements were made on a 10-m, three-bladed, downwind HAWT. A video camera was mounted on the rotor to record video images of tufts attached to the low-pressure side of a constant-chord, zero-twist blade. Load measurements were made using strain gages mounted every 10% of the blade's span, and pressure measurements were made at 80 percent of the blade's span. Pressure taps were located at 32 chordwise positions and revealed pressure distributions comparable with wind tunnel data. Inflow was measured using a vertical-plane array of eight propvane and five triaxial (U-V-W) prop-type anemometers located 10 m upwind in the predominant wind direction. Results show evidence of stall hysteresis and unsteadiness at high AOA. Correlations with analytical predictions and wind tunnel tests show good agreement at low AOA and poor agreement at high AOA.
Book Synopsis Scientific and Technical Aerospace Reports by :
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1995 with total page 456 pages. Available in PDF, EPUB and Kindle. Book excerpt: Lists citations with abstracts for aerospace related reports obtained from world wide sources and announces documents that have recently been entered into the NASA Scientific and Technical Information Database.
Book Synopsis Development of a Wind Tunnel Test Apparatus for Horizontal Axis Wind Turbine Rotor Testing by : Michael Kenneth McWilliam
Download or read book Development of a Wind Tunnel Test Apparatus for Horizontal Axis Wind Turbine Rotor Testing written by Michael Kenneth McWilliam and published by . This book was released on 2008 with total page 329 pages. Available in PDF, EPUB and Kindle. Book excerpt: Currently, wind energy presents an excellent opportunity to satisfy the growing demand without the supply and environmental problems associated with conventional energy. The engineering in wind turbines is not fully mature. There are still phenomenon, particularly dynamic stall, that cannot accurately be modeled or controlled. Dynamic stall contributes to fatigue stress and premature failure in many turbine components. The three dimensionality of dynamic stall makes these structures unique for wind turbines. Currently, flow visualization of dynamic stall on a wind turbine rotor has not been achieved. These visualizations can reveal a lot about the structures that contribute to dynamic stall.
Book Synopsis Measurements of Heat Transfer, Flow, and Pressures in a Simulated Turbine Blade Internal Cooling Passage by : Louis M. Russell
Download or read book Measurements of Heat Transfer, Flow, and Pressures in a Simulated Turbine Blade Internal Cooling Passage written by Louis M. Russell and published by . This book was released on 1997 with total page 30 pages. Available in PDF, EPUB and Kindle. Book excerpt: An experimental study was made to obtain quantitative information on heat transfer, flow, and pressure distribution in a branched duct test section that had several significant features of an internal cooling passage of a turbine blade. The objective of this study was to generate a set of experimental data that could be used for validation of computer codes that would be used to model internal cooling. Surface heat transfer coefficients and entrance flow conditions were measured at nominal entrance Reynolds numbers of 45 000, 335 000, and 726 000. Heat transfer data were obtained by using a steady-state technique in which an Inconel heater sheet is attached to the surface and coated with liquid crystals. Visual and quantitative flow-field data from particle image velocimetry measurements for a plane at midchannel height for a Reynolds number of 45 000 were also obtained. The flow was seeded with polystyrene particles and illuminated by a laser light sheet. Pressure distribution measurements were made both on the surface with discrete holes and in the flow field with a total pressure probe. The flow-field measurements yielded flow-field velocities at selected locations. A relatively new method, pressure sensitive paint, was also used to measure surface pressure distribution. The pressure paint data obtained at Reynolds numbers of 335 000 and 726 000 compared well with the more standard method of measuring pressures by using discrete holes.
Book Synopsis Aerodynamic Analysis of a Wind Turbine with Telescopic Blades by : Mustahib Imraan
Download or read book Aerodynamic Analysis of a Wind Turbine with Telescopic Blades written by Mustahib Imraan and published by . This book was released on 2013 with total page 246 pages. Available in PDF, EPUB and Kindle. Book excerpt: Telescopic Blade Wind Turbine Systems offer great benefits to the wind industry and in particular to low speed wind site for potential development and enhancement. An inherent feature of a telescopic blade system is the discontinuity or step change in chord that exists between the fixed inner blade section, and the movable or telescopic outer blade section. This is its main distinctive feature when compared to a standard wind turbine blade, and it is therefore a major point of difference from an aerodynamic performance point of view as well. This thesis attempts to investigate the effect of the sudden change in chord of a Telescopic Blade Wind Turbine System, using a combination of experimental, analytical, and computational studies. In particular, it is aimed at studying the dynamics of the flow around the step change region and its influence on blade aerodynamics; at investigating the influence of the step change and telescopic blade parameters on the turbine performance and energy output; and at developing a correlation for the losses that arise from the step change region. Performance testing was carried out at model-scale in the wind tunnel, of a Telescopic Blade Wind Turbine System with two-stage telescopic blade s (i.e. blades with two sections of different chords), having chord ratios of 0.6 and 0.4, and for blade extensions ranging 0 - 40% (in length of the first section). The power coefficient Cp of the wind turbine was found to decrease with extension, with a 25% decrease in maximum Cp obtained for a 20% blade extension. This is attributed to additional losses arising from the step change in chord. It was hypothesised that the step change region induces vortex rollup in a manner similar to that which happens at the tip. Correlations developed to quantify losses arising from the step change in the chord of a telescopic blade are in good agreement with experimental data, and this would pave the way for improved performance predictions. Investigations into the aerodynamic performance of a single telescopic blade with a step change in chord were also carried out in the wind tunnel. From the surface static pressure measurements and flow visualisation studies, it was established that the sudden change in the blade chord causes an abrupt drop in pressure around the step region, which causes vortex roll, confirming the hypothesis drawn from performance testing. Energy output analyses reveal that the percentage increase in the annual energy output for the telescopic blade wind turbine system over the corresponding non-telescopic blade system could be as high as ~48% for a blade with 40% extension at a chord ratio of 0.6 in wind class 2. For the range of shape factors, chord ratios and blade extensions studied in this research, the reduction in annual energy output due to the step change in blade chord is found to be in the range of 15 to 1% for Wind Class 2 to 7 respectively.
Book Synopsis Wind Turbine Aerodynamics by : Wen Zhong Shen
Download or read book Wind Turbine Aerodynamics written by Wen Zhong Shen and published by MDPI. This book was released on 2019-10-04 with total page 410 pages. Available in PDF, EPUB and Kindle. Book excerpt: Wind turbine aerodynamics is one of the central subjects of wind turbine technology. To reduce the levelized cost of energy (LCOE), the size of a single wind turbine has been increased to 12 MW at present, with further increases expected in the near future. Big wind turbines and their associated wind farms have many advantages but also challenges. The typical effects are mainly related to the increase in Reynolds number and blade flexibility. This Special Issue is a collection of 21 important research works addressing the aerodynamic challenges appearing in such developments. The 21 research papers cover a wide range of problems related to wind turbine aerodynamics, which includes atmospheric turbulent flow modeling, wind turbine flow modeling, wind turbine design, wind turbine control, wind farm flow modeling in complex terrain, wind turbine noise modeling, vertical axis wind turbine, and offshore wind energy. Readers from all over the globe are expected to greatly benefit from this Special Issue collection regarding their own work and the goal of enabling the technological development of new environmentally friendly and cost-effective wind energy systems in order to reach the target of 100% energy use from renewable sources, worldwide, by 2050
Book Synopsis Wind Turbine Aerodynamics and Vorticity-Based Methods by : Emmanuel Branlard
Download or read book Wind Turbine Aerodynamics and Vorticity-Based Methods written by Emmanuel Branlard and published by Springer. This book was released on 2017-04-05 with total page 632 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book introduces the fundamentals of fluid-mechanics, momentum theories, vortex theories and vortex methods necessary for the study of rotors aerodynamics and wind-turbines aerodynamics in particular. Rotor theories are presented in a great level of details at the beginning of the book. These theories include: the blade element theory, the Kutta-Joukowski theory, the momentum theory and the blade element momentum method. A part of the book is dedicated to the description and implementation of vortex methods. The remaining of the book focuses on the study of wind turbine aerodynamics using vortex-theory analyses or vortex-methods. Examples of vortex-theory applications are: optimal rotor design, tip-loss corrections, yaw-models and dynamic inflow models. Historical derivations and recent extensions of the models are presented. The cylindrical vortex model is another example of a simple analytical vortex model presented in this book. This model leads to the development of different BEM models and it is also used to provide the analytical velocity field upstream of a turbine or a wind farm under aligned or yawed conditions. Different applications of numerical vortex methods are presented. Numerical methods are used for instance to investigate the influence of a wind turbine on the incoming turbulence. Sheared inflows and aero-elastic simulations are investigated using vortex methods for the first time. Many analytical flows are derived in details: vortex rings, vortex cylinders, Hill's vortex, vortex blobs etc. They are used throughout the book to devise simple rotor models or to validate the implementation of numerical methods. Several Matlab programs are provided to ease some of the most complex implementations.
Download or read book Energy Research Abstracts written by and published by . This book was released on 1990 with total page 608 pages. Available in PDF, EPUB and Kindle. Book excerpt:
