Wind turbines will transform the kinetic energy from the wind into electricity. The amount of power a wind turbine can produce depends on blade efficiency, the design of the blades will affect the power production. More efficient blades will use the wind and make the drag as small as possible as the blades spin around.The way the blades are designed and set up on the turbine will decide how fast they spin and therefore how much power is being created from that wind. The motor that the blades are attached to will convert mechanical energy to electrical energy as it is spinning.
Procedure:
- Estimate the area of each blade
- The windmill will have no blades on it. Pick of one of the three blades and attach it to the windmill.
- The multimeter is already connected, set it to 20 DC volt (to get a voltage reading).
- Hold the leafblower four feet from the windmill, and keep it on for 30 seconds. One person should be watching the multimeter to record the highest voltage read.
- Another person should be measuring the wind speed & recording it.
- Set the multimeter to 20 k (to get the resistance)
- Hold the leafblower four feet from the windmill, and keep it on for 30 seconds. One person should be watching the multimeter to record the highest resistance read.
- Repeat steps 1 6 for the two other blades.
- Calculate the expected power of the turbine & the actual measured power
To calculate the data we used this formula:
Pturbine = 1/2pAv3
p = air density ; A = area of blade ; v = velocity (wind speed)
amperage = voltage^2/ resistance
We expected the white blade to give us the best results because it was standard blade used in windmills. Since it’s design had been honed over many years of work, it was safe to assume that the white blade would be the most effective.
Here is some of the data from our experiment:
Blue Blade-
| Voltage | Amperage | Power Output
Watts = voltage x amperage |
|
| Wind 30MPH | .95 | 6.56 | 6.232 |
White Blade-
| Voltage | Amperage | Power Output
Watts = voltage x amperage |
|
| Wind 30MPH | .85 | 14.07 | 11.95 |
Black Blade-
| Voltage | Amperage | Power Output
Watts = voltage x amperage |
|
| Wind 30MPH | 0.63 | 1.7 | 1.071 |
The other blades were not as effective at generating power because their design was not as honed as the white blades.
The Experiment:
The greatest obstacle we faced during the experiment was the calculations required for the experiment. Since we had multiple moving parts and many of our classmates. It was difficult for us to keep the data consistent since the leafblower would hit the blades at different angles it could have affected the result in different ways too.
We also enjoyed doing our colleagues’ experiments, learning about the difference between diet coke and regular cokes reaction with mentos, understanding the laws of inertia and learning about energy production was a blast!