One of the most entertaining group of experiments to try is with the blades of a wind turbine. The blades on modern turbines "catch" the wind and use it to rotate the shaft of a generator. The spinning shaft of the generator generates electricity. How well you design your blades can greatly impact how much power your turbine produces.
Blade design and engineering is one of the most complicated and important aspects of wind turbine technology. Today engineers are trying to design blades that extract as much energy from the wind as possible throughout a range of wind speeds. Plus these blades need to be durable, quiet and affordable.
Experiments with blades can be simple or very complicated, depending on how deep you want to go. Some things you can test about blades include:
There are surely many others you can come up with on your own! If you are doing this for a science fair or project you might want to focus on just a few of these variables as it can become confusing quite quickly.
The KidWind Blade Design Document (pdf) will give you a TON of information on wind turbine blade design. Read through this document to learn some important factors and neat tricks for making great blades. At KidWind we mostly use sheets of balsa wood or plastic cardboard to make our blades, but you can also experiment with cardstock, paper/styrofoam plates, pie tins, etc.
For more advanced blade designs, read the KidWind Advanced Blade Design Document.
Click here to learn a little bit more about real wind turbine blades.
Wind Turbine Blade Design (PDF) (1.6 MB) - This PowerPoint Slide show features great pictures and explanaitions of wind turbine blade science. A great introduction to modern wind turbine blade design.
Blade Design Report(PDF) - This is a short report examining power output and blades design. The data and analysis was created by a few students at the Tufts University Center for Engineering Education Outreach using Kidwind Basic and Geared PVC Turbines.This will help you understand how some of the basic variables like pitch, length and number affect power output.
http://www.lmglasfiber.com/ - This is one of the largest wind turbine blade manufactures in the world. They have a great picture archive and neat info on the testing and development of the latest blade technology. It is a neat site to poke around on, especially as you are designing your own blades.
Windpower.org Rotor Blades - The Danish Wind Industry Association is always a great resource to learn about wind energy technology. This page on wind turbine blades has a wealth of information accompanied by helpful visual aids.