1. Ted Light Jeff Robinson December 13, 2003
AAE 415 – Aerodynamic Design Final Project Presentation Large Horizontal-Axis Wind Turbine Design
Ted Light
Jeff Robinson
December 13, 2003

2. Outline Background Design Process Results Wind Energy & History
Types of Wind Turbines
Wind Turbine Aerodynamics
Design Process
Starting Point and Analysis Method
Results

3. Wind Energy & History
Wind energy has been used for thousands of years, for sailing, pumping water, grinding grain, etc.
In the early 1900s, wind turbines were used to produce direct electric current to small areas
Oil Crisis of 1970s renewed interest in wind turbines as a cheap, clean, unlimited source of energy

4. Types of Wind Turbines “Darrius” Vertical Axis Wind Turbine
Large Horizontal Axis Wind Turbine
Traditional Windmill

5. Airfoil Aerodynamics
Wind = V0
Rotation = r * W
Relative Wind = W a
Wind Speed and Turbine Rotation must be combined to find total velocity that airfoil sections “see”

6. Desired Airfoil Qualities
For a fixed-pitch, constant speed machine, recommended airfoil qualities at 0.75R are:
High L/D
Low clmax near tip reduces tendency to overpower generator in high wind speeds
Insensitive to surface roughness (bugs, birds, bullets)

7. Design Process CMARC used to analyze designs
Existing wind turbine with known geometry and performance modeled for baseline comparison
Assumed constant velocity generator
(Power) = (Moment)*(Rotation Rate)
Variation and Analysis of Designs
Geometric parameters modified

8. Analysis Strategy
Start with an existing wind turbine, then modify its geometry
Geometry varied
Airfoil section
Twist distribution
Chord distribution
Rotational rate, number of blades and span were held constant

9. Mod-2 Wind Turbine Manufactured by Boeing in late 1970s
Development sponsored by NASA

10. Mod-2 Wind Turbine Specifications
Diameter = 91.4 m
No. of Blades = 2
Average Wind Speed = 12.5 m/s
Rotation Rate = 17.5 rpm
Airfoil: NACA 23024
Power Output = 2.5 MW

11. CMARC Inputs
Rotation rate about x-axis set to that of Mod-2 wind turbine (17.5 rpm)
Many wind turbines are “constant speed”
Wind Speed set to local average wind speed for Mod-2 (12.5 m/s)
Baseline geometry emulated Mod-2 geometry, then varied

12. Results

13. Results
Blade Tip
Leading Edge
Airfoil NACA
Root Section

14. Cp Distribution

15. Wake
for
Best
Blade

16. Results

17. Questions?