Design Lab: Wind Turbine Blade Efficiency

Optimizing Wind Turbine Blade Efficiency

(adopted from KidWind at http://learn.kidwind.org/sites/default/files/blade_design.pdf) 

Context: Wind turbines convert wind into either mechanical or electrical energy. If the efficiency of a wind turbine blade can be increased, than the need for expensive, polluting power generators will be reduced. Engineers strive to design blades that extract as much energy from the wind as possible while also being durable, quiet, and cheap.

Need: As part of the design process, the wind turbine blade is crucial in the construction of a wind turbine.

Design Brief: Design and construct a a wind turbine blade that will optimize efficiency. The efficiency of your wind turbine blade will be evaluated based on the voltage and current that are produced from your turbine.

Specifications:

1. Your wind turbine blades can be constructed from any of the materials presented. Materials presented include, but are not limited to: feathers, cardboard, aluminum foil, index cards, popsicle sticks, dowel rods, etc. 
2. Designers will be given three attempts to achieve the desired results with their wind turbine blade construction, only one blade will be used for the final performance test. 

Resources:

People: Your group of two will work cooperatively as the designers, fabricators, and evaluators.

Tools/Machines: There are no tools or machines available to work with other than the wind turbine.

Materials: With your instructor's permission, you may use any materials available in the lab. 

Energy: You may use the energy generated by your group's prolific brain cells. 

Capital: Your group has spent all available capital on personnel and resources. 

Time: You have 30 minutes to design, construct, evaluate, redesign, evaluate, etc. your wind turbine blade prior to the performance test. 

Reporting: In your science notebook, put your best working model and drawings of successful and unsuccessful designs. Explain why the different models worked and didn't work. Record the current and/or voltage of each design if determined. 

De-brief Questions: 

• Have you ever seen a wind turbine in real life? 
• Why would we want to build wind turbines? 
• How much energy do we get from wind? 
• Where are wind projects built?
• What variables affect how much energy the blades can capture? (Possible answers: Length, number, pitch/angle, shape, weight, material, curvature, twist, wind speed)
• What variables affect the power output from wind turbines? (Possible answers: wind speed, generators, size of the turbine, gear ratio, blade design)
• You may want to touch on lift/drag principles, Bernoulli’s principle, the airfoil shape, twisted pitch, number of blades, variable pitch blades, what real turbine blades are made of, tip speed ratio, etc.