1. Design of Wind Turbines
P M V Subbarao
Professor
Mechanical Engineering Department

2. Wind Speed Data @50m altitude

3. Effect of tip speed ratio on sensitivity to drag

4. The Power Extraction Analysis

5. Wind Flow Past A Locked Wind Turbine

6. Signatures of Wind Turbine on Wind & Recovery

7. Characteristic Parameter of A Wind Turbine Rotor
The axial induction factor (of rotor) a is defined as:
The available power in a cross-section equal to the swept area A by the rotor is:

8. Differentiating CP with respect to a yields:
It is easily seen that CP, max = 16/27 for a = 1/3.
This theoretical maximum for an ideal wind
turbine is known as the Betz limit.

12. Geometric Design Options

13. Kinematics of Blade
At any radius r
Vwe
Ub=rw
Vfe=u
Ub=rw
Vai=u

14. Schematic drawing of the vortex system behind a wind turbine

15. Selection of Rotor Speed

17. Optimum Available Power due to Turbulent Wake
Fraction of Betz Limit

18. Effect of tip speed ratio on sensitivity to drag

19. Common Industrial Practice

20. Aerofoil Geometry of Blades
Wind = u
Rotation = r * W
Relative Wind = ur b

21. Wind Turbine Blade Specifications
Wind = V0
Rotation = r * W
Relative Wind = Vr a
Airfoil: NACA 23024
Max thickness 24% at 30.3% chord. Max camber 2.9% at 1.3% chord

22. Blade Twist

23. Aerofoil Design Blade Tip Leading Edge Airfoil NACA 65-410
Root Section