Power Point prsentation af Ris

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LOAD ALLEVIATION ON WIND TURBINE BLADES USING
VARIABLE AIRFOIL GEOMETRY
www.risoe.dk
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The variable geometry (or flap)

• 10 chord length
• Allowed deflections /- 5 deg
• Piezoelastic material

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The wing
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SHOW VIDEO (3min)
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Modelling the TE flap

• Unsteady thin-airfoil potential model

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2D model
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SHOW 2D MODEL (2min)
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3D model
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3D model structure

• Slender cantilever beam theory
• Blade length 33m
• Mode shapes and eigenfreq. 1f,2f,3f,4f,1e,2e,1T,2
  T
• Principle of virtual work
• Known structural data

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3D model aerodynamic

• Turbulent wind series Paul S. Veers
• Induced velocity Bramwell
• Dynamic inflow model TUDk
• Tip-loss factor Prandtl
• No dynamic stall (assumes un-separated flow)
• Known static lift and drag
• Dynamic flow Mac Gaunaa

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3D model control

• CONTROL FLAP USING SIMPLE PID FEEDBACK
  LOOPObject functionMinimizing equivalent
  flapwise root moment

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SHOW 3D MODEL (5min)
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3D model results (1)
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3D model results (2)
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3D model results (3)
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Open questions

• Measure
• Power output
• Gain tables