Aerodynamics Of Wind Turbines风力机空气动力学教程英文原版教程教材教案

Aerodynamics Of Wind Turbines风力机空气动力学教程英文原版教程教材教案 Aerodynamics ofWind TurbinesSecondEdition3212J&J AerodynamicTurbines15/11/071:42PM Pagei3212J&J AerodynamicTurbines15/11/071:42PM PageiiAerodynamics ofWind TurbinesSecond EditionMartin O.L.HansenLondon?Sterling,VA3212J&J AerodynamicTurbines15/11/071:42PM PageiiiSecond editionpublished byEarthscan in the UKand USAinxxFirst editionpublished byJames&James(Science Publishers)Ltd in2000Copyright?Martin O.L.Hansen,xxAll rightsreservedISBN:978-1-84407-438-9Typeset byFiSH Books,EnfieldPrinted andbound in the UKby TJInternational,PadstowCover designby NickShahFor a full listof publicationsplease contact:Earthscan812Camden HighStreetLondon,NW10JH,UKTel:+44 (0)2073878558Fax:+44 (0)2073878998Email:earthinfoearthscan.co.ukWeb:.earthscan.co.uk22883Quicksilver Drive,Sterling,VAxx6-xx,USAEarthscan publishesin associationwith theInternational Institutefor Environmentand DevelopmentAcatalogue recordfor this book is available from the BritishLibraryLibrary ofCongress Cataloging-in-Publication DataHansen,Martin O.L.Aerodynamics of wind turbines/MartinO.L.Hansen.2nd ed.p.cm.ISBN-13:978-1-84407-438-9(hardback)ISBN-10:1-84407-438-2(hardback)1.Wind turbines.2.Wind turbinesAerodynamics.I.Title.TJ828.H35xx621.45dc22xx011666The paperused forthisbookis FSC-certified andtotally chlorine-free.FSC(the ForestStewardship Council)is aninternational workto promoteresponsible management of theworlds forests.3212J&J AerodynamicTurbines15/11/071:42PM PageivContentsList ofFigures andTablesvi1General Introduction to Wind Turbines122-D Aerodynamics733-D Aerodynamics1841-D MomentumTheory for an IdealWindTurbine275Shrouded Rotors416The ClassicalBlade ElementMomentum Method457Control/Regulation andSafety Systems638Optimization789Unsteady BEMMethod8510IntroductiontoLoads andStructures10311Beam Theoryfor theWindTurbineBlade10712Dynamic StructuralModel of a WindTurbine12513Sources ofLoads on a WindTurbine13914Wind Simulation14715Fatigue15716Final Remarks162Appendix A:Basic Equationsin FluidMechanics167Appendix B:Symbols171Index1753212J&J AerodynamicTurbines16/11/079:49AM PagevList ofFigures andTablesFigures1.1Horizontal-axis wind turbine(HAWT)41.2Machine layout62.1Schematic viewof streamlinespast an airfoil72.2Definition of lift and drag82.3Explanation of the generationof lift92.4Polar for the FX67-K-170airfoil112.5Different stallbehaviour122.6Computed streamlinesfor angles of attackof5and15122.7Viscous boundary layer at the wallof anairfoil142.8Schematic viewof the shape of the boundarylayer for afavourable and an adversepressure gradient142.9Schematic viewof thetransitional process153.1Streamlines flowingover andunder a wing183.2Velocity vectorsseen frombehind awing193.3A simplifiedmodel of the vortex system on awing203.4More realisticvortex systemon awing203.5Induced velocityfrom avortex lineof strength213.6The effectiveangle of attack for a sectionin awing and the resultingforce R,lift Land induceddrag Di223.7Computed limitingstreamlines ona stall regulated wind turbine bladeat amoderately highwind speed233.8Rotor of a three-bladed wind turbine withrotor radiusR243.9Radial cutin a wind turbine rotor showing airfoils atr/R243.10Schematic drawing of thevortexsystembehind a wind turbine254.1Illustration of the streamlinespast the rotor and the axialvelocityand pressureup-and downstreamof the rotor284.2Circular controlvolume arounda wind turbine294.3Alternative controlvolume arounda wind turbine303212J&J AerodynamicTurbines15/11/071:42PM Pagevi4.4The power and thrust coefficients CpandCTas a function of the axialinduction factor a for an idealhorizontal-axis wind turbine324.5The measuredthrust coefficient CTas afunction of the axialinduction factoraand thecorresponding rotorstates334.6The expansionof the wake and the velocityjump in thewakefor the1-D modelof anideal wind turbine344.7Schematic viewof theturbulent-wake stateinduced bytheunstable shearflow atthe edge of thewake354.8The velocitytriangle for a section of the rotor364.9Velocity triangleshowing theinduced velocitiesfor asection of the blade384.10The efficiencyof anoptimum turbinewith rotation405.1Ideal flowthrough a wind turbinein adiffuser415.2Computed mass flow ratioplotted againstthe putedpower coefficientratio for a bareand ashrouded wind turbine,respectively435.3Computed powercoefficient for a rotorin adiffuser as afunction of the thrustcoefficientCT436.1Control volumeshaped as an annularelement to be used in theBEM model456.2Velocities atthe rotor plane476.3The localloads ona blade486.4A linearvariation of the loadis assumedbetween twodifferent radialpositions riandri+1526.5Different expressionsfor thethrustcoefficientCTversus theaxialinductionfactora546.6Probability f(Vi (1991)and Schlichting (1968).Figure2.6shows theputed streamlinesforaNACA63-415aerofoil atanglesofattackof5and15.For=15a trailingedge separationisobserved.The forcesontheaerofoil stemfromthepressure distributionp(x)10|Aerodynamics ofWindTurbines3212J&J AerodynamicTurbines15/11/071:42PM Page102D Aerodynamics|11Figure2.4Polar fortheFX67-K-170airfoil3212J&J AerodynamicTurbines15/11/071:42PM Page1112|Aerodynamics ofWind TurbinesFigure2.6Computed streamlinesfor anglesofattackof5and15Figure2.5Different stallbehaviour3212J&J AerodynamicTurbines15/11/071:42PM Page12andtheskin frictionwiththeair?w=?(?u/?y)y=0.(x,y)isthesurfacecoordinate systemasshowninFigure2.7and?isthedynamic viscosity.Theskin frictionismainlycontributing tothedrag,whereas theforce foundfromintegrating thepressure hasa liftanddragponent.The dragponentfrom thepressure distributionisknownastheform dragand beesverylarge whentheaerofoilstalls.The stallphenomenon isclosely relatedtoseparation oftheboundarylayer(see nextparagraph);therefore rulenumberone inreducing dragis toavoid separation.In Abbotand vonDoenhoff (1959)a lotof datacanbefound forthe NationalAdvisory CommitteeforAeronautics(NACA)aerofoils,which havebeen extensivelyused onsmallaircraft,windturbinesand helicopters.Close totheaerofoilthere existsaviscous