AAE 415 – Aerodynamic Design Final Project Presentation Large Horizontal-Axis Wind Turbine Design

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

2. Outline • Background • 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. Rotation = r *W Wind = V0 a Relative Wind = W Airfoil Aerodynamics • 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. 13.7 m 1.43 m 3.45 m 45.7 m 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 65-410 Root Section

14. Cp Distribution

15. Wake for Best Blade

16. Results

17. Questions?