wind_van_rooij - Design of Airfoils for Wind Turbine Blades...

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Unformatted text preview: Design of Airfoils for Wind Turbine Blades Ruud van Rooij (r.vanrooij@citg.tudelft.nl) Nando Timmer Delft University of Technology The Netherlands 03 May, 2004 DUWIND, section Wind Energy, Faculty CiTG 1 Delft University of Technology 13200 Bsc+ Msc students, 4750 employees Delft University Wind Energy Research Institute (Coordinator: Section Wind Energy) Faculties: • Civil Engineering and Geosciences (Wind Energy, Offshore) http://www.windenergy.citg.tudelft.nl/home/flash/index.html • Information Technology and Systems (Electrical group) • Design, Engineering and Production (Systems &Control) • Aerospace Engineering (Aero, Aeroelastics) 03 May, 2004 DUWIND, section Wind Energy, Faculty CiTG 2 Section Wind Energy (Civil Engineering and Geosciences => Aerospace Engineering) Aerodynamic research - Facilities low speed wind-tunnel open-jet wind tunnel 03 May, 2004 DUWIND, section Wind Energy, Faculty CiTG research wind turbine 3 Contents • Background • Design goals HAWT airfoils • Design approach • Performance comparison • • Effect on wind turbine power Cp • 03 May, 2004 Airfoil testing Overview HAWT airfoils DUWIND, section Wind Energy, Faculty CiTG 4 Background Operational area Control: 1.2 P ow e r 1.0 Variable RPM Power restriction High Cp 80% of Energy 0.8 0.6 0.4 0.2 W in ds spe e d (m /s) 0.0 0.0 Airfoil: 03 May, 2004 5.0 10.0 High max. L/D DUWIND, section Wind Energy, Faculty CiTG 15.0 20.0 25.0 Max. lift considerations 5 Background Blade geometry Structural: Airfoil: Outboard: t/= .15-18 - High max. L/D - Insensitive to roughness - Similar design angle Mid span: t/= .25 Inboard: t/> .30 Transition piece 03 May, 2004 DUWIND, section Wind Energy, Faculty CiTG - High max. lift (Rot. Effects) No Aerodynamic demands 6 Background Effect of rotation RFOIL code • Integral boundary layer eq. • Extended for radial flow • Radial equations • Cross flow profile Stall delay 2.50 inboard cl 2.00 mid-span 1.50 2d 1.00 0.50 parameter is c/r (= local solidity) 03 May, 2004 DU 91-W2-250 Re = 3.0x10e6 0.00 -0.50 -5.0 DUWIND, section Wind Energy, Faculty CiTG Angle (deg.) 0.0 5.0 10.0 15.0 20.0 25.0 7 Design goals HAWT airfoils steady Thickness-to-chord ratio > .28 .28 - .21 .21 > High maximum lift-to-drag ratio Low max. and benign post stall Insensitivity to roughness Low noise Geometric compatibility Structural demands 03 May, 2004 DUWIND, section Wind Energy, Faculty CiTG 8 Design approach (example DU 91-W2-250) Main features Small upper surface thickness => reduced roughness sensitivity NACA 63-425 DU 91-W2-250 03 May, 2004 DUWIND, section Wind Energy, Faculty CiTG S-Tail => Aft-loading 9 Design approach (pressure distributions DU 91-W2-250, Re = 3.0x106) - 4. 0 Low roughness sensitivity => Transition at nose for Cl_max Cp - 3. 0 11.0o - 2. 0 Low drag => Aft transition at Cl_design 7.0o Alpha= 0.0o - 1. 0 Transition Separation 0. 0 Aft-loading 1. 0 0.0 03 May, 2004 0.2 0.4 DUWIND, section Wind Energy, Faculty CiTG 0.6 x/c 0.8 1.0 10 Airfoil design (2d performance) Measurements at LST-TU Delft: Clean 1.50 1.50 Design lift cl cl 1.00 1.00 0.50 0.50 0.00 0.00 DU 91-W2-250 Re = 3.0x106 NACA 63-425 -0.50 0 03 May, 2004 50 cl/cd 100 150 -0.50 -5.0 DUWIND, section Wind Energy, Faculty CiTG 0.0 5.0 10.0 15.0 20.0 Angle (deg.) 11 Airfoil design (2d performance) Measurements at LST-TU Delft: Roughness simulated 1.50 ZZ-Tape at 5% u.s. 1.50 cl Design lift 1.00 1.00 cl 0.50 0.50 0.00 0.00 DU 91-W2-250 Re = 3.0x106 NACA 63-425 -0.50 0 03 May, 2004 30 cl/cd 60 90 -0.50 -5.0 DUWIND, section Wind Energy, Faculty CiTG 0.0 5.0 10.0 15.0 20.0 Angle (deg.) 12 Airfoil testing (Low speed low turbulence tunnel) Test section size 1.80 x 1.25 m Maximum speed 120 m/s Turbulence level 0.015% at 10 m/s 0.07% at 70 m/s Test section 03 May, 2004 DUWIND, section Wind Energy, Faculty CiTG 13 Airfoil testing (effect of leading edge thickness) DU 97-W-300 Lift coefficient 1.6 1.2 DU 96-W-180 0.8 6 Re=1.0x10 0.4 0 -5 0 5 10 15 20 25 30 35 40 angle of attack (degrees) -0.4 03 May, 2004 DUWIND, section Wind Energy, Faculty CiTG 14 Airfoil testing (effect of high Reynolds numbers) Airfoil: DU 97-W-300Mod 120 1.6 100 1.4 Cl,max (Cl/Cd)max 80 1.2 60 1.0 40 0.8 Clean 20 Zigzag tape 0.4 mm 0.6 Carborundum 60 0 0.4 0 03 May, 2004 5 Re x10 -6 10 DUWIND, section Wind Energy, Faculty CiTG 0 5 Re x10-6 10 15 Airfoil testing (360 degrees) 2.5 Cl, Cd 2 1.5 1 0.5 0 -50 0 50 100 150 200 250 300 350 400 -0.5 -1 -1.5 03 May, 2004 DU 96-W-180 Re=700,000 DUWIND, section Wind Energy, Faculty CiTG angle of attack 16 Airfoil testing (360 degrees) α=24o 2.5 Cl, Cd 2 1.5 1 0.5 0 -50 0 50 100 150 200 250 300 350 400 -0.5 -1 -1.5 03 May, 2004 DU 96-W-180 Re=700,000 DUWIND, section Wind Energy, Faculty CiTG angle of attack 17 Airfoil testing (360 degrees) α= 40o 2.5 Cl= 1.145 Cl, Cd 2 1.5 1 0.5 0 -50 0 50 100 150 200 250 300 350 400 -0.5 -1 -1.5 03 May, 2004 DU 96-W-180 Re=700,000 DUWIND, section Wind Energy, Faculty CiTG angle of attack 18 Airfoil testing (360 degrees) α=90o 2.5 Cl= 0.10 Cd= 1.914 Cl, Cd 2 1.5 1 0.5 0 -50 0 50 100 150 200 250 300 350 400 -0.5 -1 -1.5 03 May, 2004 DU 96-W-180 Re=700,000 DUWIND, section Wind Energy, Faculty CiTG angle of attack 19 Airfoil testing (360 degrees) α= 160o 2.5 Cl= -.627 Cl, Cd 2 1.5 1 0.5 0 -50 0 50 100 150 200 250 300 350 400 -0.5 -1 -1.5 03 May, 2004 DU 96-W-180 Re=700,000 DUWIND, section Wind Energy, Faculty CiTG angle of attack 20 Airfoil testing (360 degrees) α= 194o 2.5 Cl= 0.541 Cl, Cd 2 1.5 1 0.5 0 -50 0 50 100 150 200 250 300 350 400 -0.5 -1 -1.5 03 May, 2004 DU 96-W-180 Re=700,000 DUWIND, section Wind Energy, Faculty CiTG angle of attack 21 Airfoil testing (360 degrees) α= 224o 2.5 Cl, Cd Cl= 0.811 2 1.5 1 0.5 0 -50 0 50 100 150 200 250 300 350 400 -0.5 -1 -1.5 03 May, 2004 DU 96-W-180 Re=700,000 DUWIND, section Wind Energy, Faculty CiTG angle of attack 22 Airfoil testing (360 degrees) α= 270o 2.5 Cl= -0.11 Cd= 1.832 Cl, Cd 2 1.5 1 0.5 0 -50 0 50 100 150 200 250 300 350 400 -0.5 -1 -1.5 03 May, 2004 DU 96-W-180 Re=700,000 DUWIND, section Wind Energy, Faculty CiTG angle of attack 23 Airfoil testing (360 degrees) α= 316o 2.5 Cl=- 0.971 Cl, Cd 2 1.5 1 0.5 0 -50 0 50 100 150 200 250 300 350 400 -0.5 -1 -1.5 03 May, 2004 DU 96-W-180 Re=700,000 DUWIND, section Wind Energy, Faculty CiTG angle of attack 24 Airfoil testing (aerodynamic devices) • Stall strips Ø 1.2 mm 1.5 1.5 cl cl 1.0 1.0 0.5 0.0 0.00 0.5 DU 93-W-210 R = 2.0x106 0.0 0.01 0.02 cd 0.03 -10 0 -0.5 -0.5 10 o α ( ) 20 no trip wire wire at 0.5%c l.s. -1.0 -1.0 03 May, 2004 DUWIND, section Wind Energy, Faculty CiTG wire at 0.25%c l.s. 25 Airfoil testing (aerodynamic devices) • Vortex generators 2.0 2.0 Cl Cl 1.6 1.6 1.2 1.2 0.8 0.8 0.4 0.4 0.0 0.0 DU 91-W 2-250 6 Re = 2.0x10 -0.4 0.0 30.0 60.0 90.0 120.0 -0.4 -5.0 Cl/Cd 03 May, 2004 DUWIND, section Wind Energy, Faculty CiTG VG at x/c= 0.2 VG at x/c= 0.3 Clean 0.0 5.0 10.0 15.0 20.0 25.0 Alpha (deg.) 26 Effect on wind turbine performance (2d stationary performance) Calculated optimal element performance at mid-span for TSR= 7.5 “Static load” Cp_elem Cl_max*c Clean c/R L/D-max AH 93-W-257 0.106 122 0.149 DU 91-W2-250 0.105 125 0.119 DU 91-W2-250 NACA 63-425 NACA 63-425 Loading Cp .56 4% -0.06% 0.143 .561 0% 0% 119 0.152 .56 6% -0.24% 0.135 60 .155 .532 8% -5.1% 0.212 39 .212 .503 48% -10.2% ZZ-tape 5% u.s. * “Static load” reference based on 1 year gust for fixed pitch blades 03 May, 2004 DUWIND, section Wind Energy, Faculty CiTG 27 Effect on wind turbine performance (2d stationary performance) local Aero Cp 25% thick airfoil class (mid-span for TSR= 7.5) 0.57 DU 91-W2-250 0.56 -5% 0.55 0.54 -10% 0.53 0.52 “Rough” 0.51 NACA 63-425 0.50 0 03 May, 2004 20 40 60 80 max. L/D DUWIND, section Wind Energy, Faculty CiTG 100 120 140 28 Overview of HAWT airfoils General aviation airfoils • NACA 63-4xx and NACA 63-6xx series • NACA 64-4xx Dedicated airfoils • S8xx series (NREL, USA) • FFA W-xxx (FOI, Sweden) • Risø-A1-xxx (also B, P-series, Risø, Denmark) • DU xx-W-xxx (Delft, Netherlands) 03 May, 2004 DUWIND, section Wind Energy, Faculty CiTG 29 Overview of HAWT airfoils • Overview of DU-airfoils and users DU 95-W-180 DU 96-W-180 DU 00-W-212 DU 91-W2-250 DU 97-W-300 DU 00-W-350 DU 93-W-210 GE-Wind, REpower, Dewind, Suzlon, Gamesa, LM Glasfiber, NOI Rotortechnik, Fuhrlander, Pfleiderer, EUROS, NEG Micon, Umoe blades, Ecotecnia …….. 03 May, 2004 DUWIND, section Wind Energy, Faculty CiTG 30 Next steps: Extending to all operational situations : • Measurements => “high” Reynolds number => chart unsteady behavior of DU airfoils New airfoil designs : • • Control of rpm only => Low TSR Low Cl-max, benign stall => High TSR Low drag • 03 May, 2004 Very thick airfoils for lightweight blades Aero-elastic tailoring => Dynamic airfoil design (Probably low Cl-max) DUWIND, section Wind Energy, Faculty CiTG 31 ...
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This note was uploaded on 11/13/2011 for the course AEE 495 taught by Professor O.uzol during the Spring '11 term at Middle East Technical University.

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