You may have seen a few different types of windmills and turbines during your research into wind energy. Some turbines have lots of blades and others do not. Some examples of different rotors are shown below. The area of rotor disc covered by blades in each image is very different in each of these devices. These turbines are designed to do two very different things: The windmill on the left is designed to pump water; the turbine on the right is designed to generate electricity.
The ratio of the total area for all blades to the total swept area is called the solidity of the turbine. Solidity is calculated using the following equation,
where n is the number of blades, a is the area of a single blade, and A is the swept area of the turbine.
In this experiment, you will measure the planform area, the area the blade projects onto the plane of rotation, using the Photo Analysis tool in Logger Pro. You will use the total planform area for all blades to calculate the solidity of the wind turbine. You can then investigate how the turbine solidity affects power output.
Measure the total blade planform area.
Calculate the total area swept by a wind turbine blade.
Calculate solidity of a wind turbine.
Investigate the relationship between power output and solidity.
Sensors and Equipment
This experiment features the following Vernier sensors and equipment.