1. Good Wind Hunting
Final Presentation: The Two-Bladed HAWT
Engineers:
Andrew Fountain
Shadae Boakye-Yiadom
Marshall Gordon
Joe Moss
April 16, 2015
Prepared for Oor, Dean, and Airy

2. Overview
● Lack of an established electrical grid in Guatemala
● We were asked to design a small-scale wind turbine by ODA
Objectives:
● Produce consistent power
● Low cost
● Durable
● Easy to assemble
● Safe

3. Two-bladed HAWT

4. Agenda
● Discuss prototype design
● Describe design changes
● Outline budget
● Analyze performance
● Recommend improvements for future designs

5. Prototype Design
2m
0.72m2
Side view
Front view

6. Prototype Design
Top view
Side view

7. Blades
Initial:
● One piece
● No hub
● 6 cm chord length
Final:
● 2 separate blades
● Central hub
● 10 cm chord
length

8. Shaft
Hub

9. Transmission
● 9:4 gear ratio
● Hollow shaft

10. Yaw System
Lazy Susan Fin

11. Preliminary Budget
Item Cost/
Item $
Quantity Total Cost $
4in Lazy Susan 4.48 1 4.48
4in steel hose ties 1.39 3 4.17
2.5ft Steel rod shaft 5/8ths inch 5.77 1 5.77
1 meter long by 0.12 meter diameter PVC pipe 16.67 1 16.67
3”x3” Large timber rod, at least 1.5 meter long 3.97 1 3.97
Gear set 15.00 1 15.00
1 inch phillips head screws 4.37 1 4.37
Total (including 6% tax) 62.81

12. Item
Cost/
Item ($) Quantity Total Cost ($)
4in Lazy Susan 4.48 1 4.48
4in steel hose ties 1.39 3 4.17
2.5ft Steel rod shaft 1/2 inch bore 5.77 1 5.77
0.12 meter diameter PVC pipe 6.67 1 6.67
3”x3” Large timber rod (1.5m long) 3.97 1 3.97
Gear set and hubs 22.45 1 22.45
½ inch Bearings* 5.00 2 10.00
Plywood* 10.00 1 10.00
Wiring and Resistors* 1.00 1 1.00
Total Expenditure 47.51
Total* (including 6% tax) 68.71
Final Budget
● Goal was < $100
● We were well under
this goal
● Final budget was $6
more than initial, due
to gear set
● Items with * were
found in the lab and
not purchased

13. Performance Analysis
● Objectives:
o Produce consistent power- inconclusive
o Low cost- met
o Durable- met
o Easy to assemble- met
o Safe- met

14. Performance Analysis
● Average Voltage: 0.567 Volts
● Resistance: 20 Ohms
● Average Power: 0.0167 Watts
● Average Wind Speed: 2.84m/s
● Average Efficiency: 0.164%
● Cut-in Speed: ~1m/s
● Tip speed ratio: 14.2

15. Technical Recommendations
● Optimize blades
o Use one piece for blades instead of two
o Make the blades as thin as possible
o Increase width of the blades
o Test to find optimal pitch angle
● Increase electrical resistance
● Decrease bearing resistance
● Increase sturdiness

16. Conclusion
● Implemented the 2-Bladed HAWT
design
● Our design worked!
● Met most of our objectives
● Future designs should:
o Optimize blades
o Increase electrical resistance
o Use improved bearings
o Increase sturdiness
“I was raised to be charming,
not sincere”