Download or read book Numerical Simulation of a Flat Back Airfoil for Wind Turbine Applications written by Matthew Fuller and published by . This book was released on 2010 with total page 53 pages. Available in PDF, EPUB and Kindle. Book excerpt: Wind energy provides an attractive power source as an alternative to fossil fuels because it is abundant, clean, and produces no harmful emissions. To extract more energy from the wind we need to increase the wind turbine size. However, the increase in size has begun to reach a limit in terms of material composition and structural stability. To quell the trend of increasing size in wind power systems alternative wind turbine blade designs are investigated and evaluated to increase power production and efficiency of present size machines. Flat back airfoils have been proposed for the inboard region of large wind turbine blades because they provide structural and aerodynamic advantages. In this work we will investigate the aerodynamic performance of flat back airfoils with computational fluid dynamics techniques. To reduce the drag and noise inherent from the blunt trailing edge, a splitter plate with varying lengths is added to the trailing edge of the airfoils. Comparisons are made with experimental data. Excellent agreement is achieved with the measurements. Our numerical simulations show that the flat back airfoil can increase lift production as much as 20%. The splitter can effectively reduce drag by as much as 20% and tonal noise by as much as 20 dB.
Download or read book Development of Form Adaptive Airfoil Profiles for Wind Turbine Application written by Irfan Ahmed and published by kassel university press GmbH. This book was released on 2017-10-23 with total page 212 pages. Available in PDF, EPUB and Kindle. Book excerpt: The following work summarizes the development of shape-adaptive airfoil profiles for wind turbine application. The underlying motivation of this work is the potential cost effectiveness of wind power conversion through the introduction of shape-adaptive airfoils in future wind turbine blades. The employment of shape adaption system in the wind turbine blade geometry would facilitate a more efficient power harvesting for the next generation of smart wind turbines. In the scope of this work, the concepts of the dedicated shape-adaptive airfoil profiles for wind turbine application are investigated in light of their aerodynamic performances. The concepts of the actuation system are developed while taking pre-defined design boundary conditions suitable for wind turbine application into consideration. A novel numerical approach is developed towards the simulation of fluid-structure interaction for prototype shape-adaptive airfoils. The numerical scheme is employed in designing the shape-adaptive blade prototypes. Effort has been given to develop a unique actuator system for wind turbine application. In a next step, experimental investigations are carried out to quantize the aerodynamic flow-field around the shape-adaptive airfoils. Parallelly, experimental investigations are carried out on a rigid NACA 0012 airfoil to log its performance at different stagger angles. In a further step, numerical investigations are carried out on the different airfoil configurations. Finally, performance analyses of the airfoils are carried out. The shape-adaptive airfoils outperform the rigid NACA 0012 airfoil for the desired performance envelope.
Download or read book Flatback Airfoil Wind Tunnel Experiment written by Jonathon P. Baker and published by . This book was released on 2008 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt: A computational fluid dynamics study of thick wind turbine section shapes in the test section of the UC Davis wind tunnel at a chord Reynolds number of one million is presented. The goals of this study are to validate standard wind tunnel wall corrections for high solid blockage conditions and to reaffirm the favorable effect of a blunt trailing edge or flatback on the performance characteristics of a representative thick airfoil shape prior to building the wind tunnel models and conducting the experiment. The numerical simulations prove the standard wind tunnel corrections to be largely valid for the proposed test of 40% maximum thickness to chord ratio airfoils at a solid blockage ratio of 10%. Comparison of the computed lift characteristics of a sharp trailing edge baseline airfoil and derived flatback airfoils reaffirms the earlier observed trend of reduced sensitivity to surface contamination with increasing trailing edge thickness.
Download or read book Computational Design and Analysis of Flatback Airfoil Wind Tunnel Experiment written by Cornelis P. Van Dam and published by . This book was released on 2008 with total page 40 pages. Available in PDF, EPUB and Kindle. Book excerpt: "A computational fluid dynamics study of thick wind turbine section shapes in the test section of the UC Davis wind tunnel at a chord Reynolds number of one million is presented. The goals of this study are to validate standard wind tunnel wall corrections for high solid blockage conditions and to reaffirm the favorable effect of a blunt trailing edge or flatback on the performance characteristics of a representative thick airfoil shape prior to building the wind tunnel models and conducting the experiment. The numerical simulations prove the standard wind tunnel corrections to be largely valid for the proposed test of 40% maximum thickness to chord ratio airfoils at a solid blockage ratio of 10%. Comparison of the computed lift characteristics of a sharp trailing edge baseline airfoil and derived flatback airfoils reaffirms the earlier observed trend of reduced sensitivity to surface contamination with increasing trailing edge thickness."--p. 3.
Download or read book Aerodynamic Study on the Design and Optimization of Flatback Airfoils for Wind Turbine Applications written by Ona Canals Seix and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Update the available literature on current flat back airfoils.Continue the optimization of flatback surfaces obtainedfrom conventional sections and develop completely new designs with the objective of obtaining better aerodynamic characteristics than conventional airfoils.
Download or read book Numerical Investigation of Wind Turbine Airfoils Under Clean and Dusty Air Conditions written by Siyuan Chen (Mechanical engineer) and published by . This book was released on 2020 with total page 43 pages. Available in PDF, EPUB and Kindle. Book excerpt: The focus of research in this thesis is on numerical simulation of airflow around wind turbine airfoils (S809, S814 and S1210) under both clean and dusty air conditions by using Computational Fluid Dynamics (CFD). The physical geometries of the airfoils and the meshing processes are completed in the ANSYS Mesh package ICEM. The simulations and post-processing are done by ANSYS FLUENT. For cases of clean air condition, Spalart-Allmaras (SA), realizable k-[epsilon] and Wray-Agarwal (WA) turbulence models are employed in the calculations. The results are compared with the experimental data for validation. For dusty air condition, simulation of the two-phase flow is conducted using the discrete phase model (DPM) for various concentrations of dust particles using the realizable k-[epsilon] model and WA turbulence models. The results are compared with the clean air simulations to illustrate the effect of dust contamination on the aerodynamic performance of the airfoils. Finally, some conclusions are drawn on how several factors influence the aerodynamic performance of the airfoils and suggestions are made to improve the wind energy conversion efficiency of airfoils under clean and dusty air conditions.
Download or read book Handbook of Wind Energy Aerodynamics written by Bernhard Stoevesandt and published by Springer Nature. This book was released on 2022-08-04 with total page 1495 pages. Available in PDF, EPUB and Kindle. Book excerpt: This handbook provides both a comprehensive overview and deep insights on the state-of-the-art methods used in wind turbine aerodynamics, as well as their advantages and limits. The focus of this work is specifically on wind turbines, where the aerodynamics are different from that of other fields due to the turbulent wind fields they face and the resultant differences in structural requirements. It gives a complete picture of research in the field, taking into account the different approaches which are applied. This book would be useful to professionals, academics, researchers and students working in the field.
Download or read book CFD Analysis of a Wind Turbine Airfoil with Flap written by Heyou Tan and published by . This book was released on 2020 with total page 34 pages. Available in PDF, EPUB and Kindle. Book excerpt: The focus of this thesis is to evaluate the aerodynamic performance of NREL S809 airfoil (widely used airfoil for wind turbine blades) with a trailing-edge flap by numerical simulations. In the simulations, the geometry of the flap and the gap between the main element and the flap are varied. The airfoil geometry is created in Design Modeler and structured mesh around the airfoil is generated using meshing software ICEM. Simulations are performed using the Reynolds-Averaged Navier-Stokes (RANS) equations with SST k-[omega], Spalart-Allmaras (SA) and Wray-Agarwal (WA) turbulence models at Reynolds number 106 at angles of attack of 0, 5°, 10°, 15°, and 20°. First, numerical solutions are validated against the experimental data for S809 airfoil without flap. Then the numerical simulations are conducted with a triangular Gurney flap at various angles of attack. The lift coefficient and the drag coefficient are calculated and are compared with S809 airfoil without flap to evaluate the effect of flap on the airfoil performance. The pressure contours, turbulent kinetic energy contours, and streamlines are plotted and compared for airfoil without and with flap to analyze the details of the flow field. Computed results show that the presence of trailing-edge flap provides higher lift and lift-to-drag ratio compared to original airfoil demonstrating its promise for larger wind energy extraction.
Download or read book Computational Methods and Experimental Measurements XV written by G. M. Carlomagno and published by WIT Press. This book was released on 2011 with total page 737 pages. Available in PDF, EPUB and Kindle. Book excerpt: Containing edited versions of most of the papers presented at the Fifteenth International Conference on Computational Methods and Experimental Measurements, this book reviews the latest work on these two approaches, and the interaction between them.
Download or read book Analysis of Turbulent Boundary Layers written by Tuncer Cebeci and published by Elsevier. This book was released on 2012-12-02 with total page 423 pages. Available in PDF, EPUB and Kindle. Book excerpt: Analysis of Turbulent Boundary Layers focuses on turbulent flows meeting the requirements for the boundary-layer or thin-shear-layer approximations. Its approach is devising relatively fundamental, and often subtle, empirical engineering correlations, which are then introduced into various forms of describing equations for final solution. After introducing the topic on turbulence, the book examines the conservation equations for compressible turbulent flows, boundary-layer equations, and general behavior of turbulent boundary layers. The latter chapters describe the CS method for calculating two-dimensional and axisymmetric laminar and turbulent boundary layers. This book will be useful to readers who have advanced knowledge in fluid mechanics, especially to engineers who study the important problems of design.
Download or read book Flatback Airfoils written by Camille Nadine Metzinger and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: A two-dimensional experimental examination of the effect of splitter plate length on both aerodynamic performance and vortex shedding behavior as well as an initial evaluation of the shedding coherence for a flatback airfoil is presented. The FB-3500-1750 is a thick airfoil with a blunt trailing edge (also called a flatback airfoil) designed for the inboard region of wind turbine blades. Its maximum thickness is 35% of the airfoil chord, with a trailing edge thickness (t[subscript TE]) of 17.5%. In the present study, the FB-3500-1750 airfoil was tested in the University of California, Davis aeronautical wind tunnel at a chord Reynolds number of 666,000. Drag reductions of at least 27% from the baseline were observed with the inclusion of a splitter plate length of 50% t[subscript TE]. Additionally, increasing splitter plate length was shown to continue to decrease the base drag. Maximum lift reductions and earlier stall angles were also observed with increasing splitter plate length though with the 50% t[subscript TE] configuration, the loss in maximum lift coefficient was limited to 5%. Examining vortex shedding behavior, increases in the nondimensional shedding frequency, Strouhal number, were seen with increasing splitter plate length for the measured range. Lastly, for the baseline FB-3500-1750 airfoil, the spanwise correlation length of the vortex shedding was determined as 4-5.5 t[subscript TE] for all the angle of attack and transition (fixed and free) configurations evaluated.
Download or read book Introduction to Wind Turbine Aerodynamics written by A. P. Schaffarczyk and published by Springer. This book was released on 2014-06-21 with total page 276 pages. Available in PDF, EPUB and Kindle. Book excerpt: Wind-Turbine Aerodynamics is a self-contained textbook which shows how to come from the basics of fluid mechanics to modern wind turbine blade design. It presents a fundamentals of fluid dynamics and inflow conditions, and gives a extensive introduction into theories describing the aerodynamics of wind turbines. After introducing experiments the book applies the knowledge to explore the impact on blade design.The book is an introduction for professionals and students of very varying levels.
Download or read book Wind Energy Explained written by James F. Manwell and published by John Wiley & Sons. This book was released on 2010-09-14 with total page 704 pages. Available in PDF, EPUB and Kindle. Book excerpt: Wind energy’s bestselling textbook- fully revised. This must-have second edition includes up-to-date data, diagrams, illustrations and thorough new material on: the fundamentals of wind turbine aerodynamics; wind turbine testing and modelling; wind turbine design standards; offshore wind energy; special purpose applications, such as energy storage and fuel production. Fifty additional homework problems and a new appendix on data processing make this comprehensive edition perfect for engineering students. This book offers a complete examination of one of the most promising sources of renewable energy and is a great introduction to this cross-disciplinary field for practising engineers. “provides a wealth of information and is an excellent reference book for people interested in the subject of wind energy.” (IEEE Power & Energy Magazine, November/December 2003) “deserves a place in the library of every university and college where renewable energy is taught.” (The International Journal of Electrical Engineering Education, Vol.41, No.2 April 2004) “a very comprehensive and well-organized treatment of the current status of wind power.” (Choice, Vol. 40, No. 4, December 2002)
Download or read book Summary of Low Speed Airfoil Data written by Michael S. Selig and published by Soartech. This book was released on 1995 with total page 320 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Catalog of Low Reynolds Number Airfoil Data for Wind Turbine Applications written by Stan J. Miley and published by . This book was released on 1982 with total page 638 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Numerical Simulation of the Flow Over Flapping Airfoils in Propulsion and Power Extraction Regimes written by Muhammad Arif Ashraf and published by . This book was released on 2010 with total page 193 pages. Available in PDF, EPUB and Kindle. Book excerpt: Inspired by the natural flying and swimming creatures, the application of flapping wings has attracted a great deal of attention from the scientific community in recent years. On one hand, flapping wings are expected to replace conventional rotor systems to build Micro and Nano Aerial Vehicles (MAVs and NAVs) operating at low Reynolds number while on the other hand they are also being investigated for the role of power generation in conjunction with conventional rotary wind turbines. For the development of MAVs/NAVs and understanding of unsteady aerodynamics, the current thesis fills the gaps in the current state of the flapping wing aerodynamics research. Firstly, at Reynolds number Re = 20000, the effect of large amplitude motions on the plunging airfoil propulsion is investigated with both two-dimensional (2D) and three-dimensional (3D) Navier-Stokes (NS) simulations. For a given plunging frequency, it is shown that increasing the amplitude of plunging airfoil motion causes the flow to be chaotic. From 3D simulations, it is shown that the chaotic force generation is not an artefact of 2D assumption. Secondly, the effect of airfoil shape (thickness and camber) variation on thrust and efficiency of a flapping airfoil at Reynolds number 200, 2000, 20000 and 2 x 106 is assessed with 2D NS and Unsteady Panel Method (UPM) simulations. It is found that for different Reynolds numbers, there exists an optimum thickness of symmetric airfoil section for maximum thrust and propulsive efficiency. The role of leading edge vortices is shown to be key to the observed performance variation. It is also shown that varying camber does not provide any benefit in terms of thrust or propulsive efficiency. Flapping airfoils can also be exploited to function as power generators, NS simulations are performed to study different configurations of flapping airfoils as power than the sinusoidal counterpart and the fully flow-driven simulation results show the practicality of flapping wing power generators. power generators which include single and two foils in tandem arrangement with prescribed sinusoidal and non-sinusoidal flapping motions at Re = 20000. Also, a numerical strategy is developed to model a fully flow-driven flapping foil power generator by utilising the aero-elastic response to the lift and moment acting on it. It is found that non-sinusoidal motion produces around 20% more power than the sinusoidal counterpart and the fully flow-driven simulation results show the practicality of flapping wing power generators.
Download or read book Advances in Wind Power written by Rupp Carriveau and published by BoD – Books on Demand. This book was released on 2012-11-21 with total page 378 pages. Available in PDF, EPUB and Kindle. Book excerpt: Today's wind energy industry is at a crossroads. Global economic instability has threatened or eliminated many financial incentives that have been important to the development of specific markets. Now more than ever, this essential element of the world energy mosaic will require innovative research and strategic collaborations to bolster the industry as it moves forward. This text details topics fundamental to the efficient operation of modern commercial farms and highlights advanced research that will enable next-generation wind energy technologies. The book is organized into three sections, Inflow and Wake Influences on Turbine Performance, Turbine Structural Response, and Power Conversion, Control and Integration. In addition to fundamental concepts, the reader will be exposed to comprehensive treatments of topics like wake dynamics, analysis of complex turbine blades, and power electronics in small-scale wind turbine systems.
