Flow control to manipulate lift of wind turbines at the blade scale
Caroline Braud*, Annie Leroy**, Emmanuel Guilmineau*, Sophie Baleriola**, Vincent Jaunet*, Stéphane Loyer**, Thibaud Piquet*, Sandrine Aubrun**, Philippe Devinant**
(*) LHEEA, Ecole Centrale Nantes, F-44321 Nantes Cedex 3, France(**) Université d'Orléans, INSA CVL, PRISME, EA 4229, F-45072, Orléans, France
SMARTEOLE (DS0205)
Objective:Improve wind energy production by proposing innovative control solutions
BladeWind TurbineWind Turbine Farm
PRISME LHEEA/LAASMaïa Eolis Avent LIDARIFPen
Maïa Eolis, Avent LIDARIFPenPRISME
PRISME LHEEA/LAAS
Control at blade scale:
compensate atmospheric perturbation at the blade scale → increase wind turbine life time
= pitch control but local
∆L < 0
∆L > 0
NACA65(4)-421CC profile(Vergnet SA)
x/c
y/c
0 0.2 0.4 0.6 0.8 1
-0.1
0
0.1α0 = +1°
Rounded (curvature 2%)Camber increasedChord = 0.3 mLenght = 1.1 m
Circulation control:
Discrete square jets
Control configuration(continuous)
D = 1 mmλ = 21mm0 < Cµ <0.199
2D Slot jet
2D URANS equations
Turbulence: k-ω SST
ISIS-CFD (ECN-CNRS)
2D wall jet
Experimental tools
Measurements : - Surface pressure - Lift and drag (balance)- PIV
Wind tunnel : Close-return wind tunnel (PRISME)Section test of 2 × 2m2 Operating speed of 10 m/sRec = 200 000
Baseline flow (α = 5°):
2D wall jet Results:
Control parameters: V=18kV et f=1KHz
Multi-DBD actuators
Results:
y/D=8.25 y/D=0
Discrete square jets
(α = 5°)
Results: 2D Slot jet (α = 5°)
Comparisons:Momentum coefficient :
Cµ = Qm U
j/(P∞ S)
With Qm the injected mass flow rate P∞ the free-stream dynamic pressure
S the controlled surface U
j the controlled jet exit velocity
2D wall jet: Cµ = ∫ ∫ ρju
j
2(y) dydz / (1/2 ρ∞ U∞2S)
Discrete square jets: Cµ = 2. (PjM
j
2Sj)/(PM∞
2S)
2D Slot jet: Cµ = (Uj2D
j)/(U∞
2D)
Cµ = 0.004
Cµ = 0.019
2D wall jet versus Discrete square jets:
2D Slot jet versus Discrete square jets:
→ 2D wall versus discrete jets: Less Cµ needed for same efficiency
→ 2D Slot jet versus discrete jets :3D effect from discrete jets more efficient, but needs more Jets ...
Conclusions:- Modified NACA65(4)421 wind turbine blade profile (Vergnet)
- Different actuators: 2D wall jet, Discrete jets, 2D Slot jet - Advantages/disadvantages: - 2D wall jet:
* good orientation of the controlled jet * two ways (+/- ∆CL)* low Cµ
- Discrete jet* Cµ up to 0.199* one way (+ ∆CL)* Improvement: orientation and orifice spacing
- 2D Slot jet actuator: * one way (+ ∆CL)* realistic ?
Perspectives
- 3D wing with discrete jets (lower spacing between jets)
- Open-loop measurements → Dynamic identification
- Closed-loop
