1. PDR: 2/22/08 Pinwheel Technologies (C3) Heather Blaha Matt Fuxa Joey King Michael McConnell Domenic Tassoni

2. Recap Vertical Wind Turbine Drag Based

3. Action Items Prototype Requirements Prototype Requirements  Is it feasible?  Is it relevant? Turbine Blade Geometry Turbine Blade Geometry  Height  Width  Curvature

4. Prototype Requirements Spins Spins Portable Portable No part over 4’ No part over 4’ <50 lbs <50 lbs Stable Stable Interchangeable Shaft Interchangeable Shaft Set-up Time Set-up Time 2 people, 15 min 2 people, 15 min Electrical Output Satisfies power requirement Multiple Speed Conditions Low and High Wind Energy Storage Battery Embedded Intelligence Current routed from a full battery to resistive heater.

5. Width of Turbine  Moment of inertia increases exponentially with width.  Wind energy function of area, increases linearly.  Conclusion: Pick a width and vary height to satisfy requirements.  Width of 0.75 meters decided upon.

6. Height of Turbine Increased height increases wind energy, decreases stability. Increased height increases wind energy, decreases stability. Calculations based on summing moments around back edge of base. Calculations based on summing moments around back edge of base. 3.5’ confirmed height. 3.5’ confirmed height. Stability increased by widening base Stability increased by widening base Wind Velocity (mph) Max Blade Height (m) 300.924 290.972 281.008 271.068 261.116 251.176 241.2

7. Blade Curvature Semi-cylindrical blades Semi-cylindrical blades Efficiency declines as the radius of the blade is increased. Efficiency declines as the radius of the blade is increased. Blades greater than a certain radius are not feasible (negative efficiency!) Blades greater than a certain radius are not feasible (negative efficiency!)

8. Current Status Trade Studies Complete Trade Studies Complete Group Discussion of All Studies Group Discussion of All Studies Turbine Blades Turbine Blades  Width, Height, Curvature Drive Shafts Drive Shafts  Dimensions, Interchangeable On-schedule - No “Show Stoppers” On-schedule - No “Show Stoppers”

9. Next Week’s Action Items Order/Procure Key Parts Order/Procure Key Parts Aluminum for blades. Aluminum for blades. Shafts and bearings. Shafts and bearings. HDPE for end caps. HDPE for end caps. Obtain battery locally. Obtain battery locally. Look into scrap aluminum for base. Look into scrap aluminum for base. Detailed CAD Model Detailed CAD Model Fully illustrates key concept features. Fully illustrates key concept features. Incorporate calculated dimensions. Incorporate calculated dimensions.

10. Questions?