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Conservation of Green House Gases with Wind Turbines and a Reusable
Energy SourceApril 30, 2015
Alabama School of Fine ArtsMath &Science Department
Honors PhysicsKimal Honour Djam
Eric Cheng (leader), Colin Bamford (co-leader),Azka Aleezada (blade design engineer), Kayla White
(base and blade constructor)
Overview of the Project
Throughout the entire semester we have done research on the science of wind turbines.
We created a small scale model of a sample wind turbine with a 8 to 1 gearbox ratio connected to a generator.
After that, we created sample blades to test for efficiencyit's mean power.
Finally, we wrote a wind turbine report on everything that we did over the entire semester.
Goals of the Project
The purpose of this project is to try to preserve what is left
of the ozone layer by using natural and reusable
resources.
A second goal was to find the blade that gave us the most
power from the wind.
Theory and Background
Wind can be thought of as an indirect source of solar
energy. Heat from the sun interacts with the earth, air in
areas of high pressure move to areas of low pressure to
create wind. High speed propeller or tubular types of
windmills have low torque, require less room, and are
generally most useful for producing electricity. As air hits
the blades or surface of the windmill’s propellers, the air
particles are pushed down the slope of the surface, the
propeller is moved resulting in rotation. Some blades are
designed much like an airplane wing, creating an airfoil
effect. As the air passes over the “wing”, it creates an area
of low pressure on the other side, forcing the “wing” up.
Theory and Background - Continued
There are many hurdles to jump over in making an
efficient wind turbine. You have to make them tall to
escape air turbulence, make them sturdy and also find a
way to get the most power out of the wind. We aimed to do
this in our project.
Hypothesis
Our hypothesis for torque was, “If our wind turbine bladeshave more torque then the mean current and potential wouldincrease.”
Our hypothesis for drag was, “If our wind turbine blades haveless drag then the mean current and potential wouldincrease.”
To increase torque, you would create multiple number of the same type of blade.
To decrease drag, you would create shorter blades or bladesthat don’t hold as much weight at the front.
Hypothesis - Continued
One main problem with the hyptheses is that we are
beginners to the science of wind turbines. We had to make
guesses on the knowledge we had or that we had gathered.
On the other hand, the websites we were suggested to go
to provided an almost positive confirmation of parts of our
hypotheses.
Useful Principles
A wind turbine cannot extract any more than 59% of the
energy carried by the wind which is referred to as Betz
limit or Betz law.
In this project, the power coefficient is considered to be 0.4
and the air density to be 1.23 kg/m3. The fan used in the
project is the TPI 30 inch standard industrial fan with
pedestal mount. It has mean wind speed of 349.28 m/s.
Design
We created five blade designs, but only chose to make two.
This is the first design.
Blade #1
Design - Continued
Here is the second design.
Blade #2
Reasons for Choosing Blades
We chose blade #1 because:1. It had ok torque.
2. There is some Bernoulli effect
3. There is small drag
4. There is ok lift
We chose blade #2 because:1. There is minimum drag
2. There is ok torque
3. The blade would have a good Bernoulli effect.
Design Process
1. We created sketches of our blade designs on a thinpiece of cardboard.
2. After that, we cut out the blades with scissors.
3. Next, we hot glued dowls an inch from the bottom ofthe blade.
4. We covered the bottom of the first blade with masking tape and covered the front of both blades with duct tape.
5. Finally, we tested the blades.
Testing the Blades
We tested the blades by connecting the generator to an
energy sensor.
Then we took the results for each of the blades.
Blade #1 Blade #2
Results for Blade #1
Results for Blade #2
Conclusion
Our first blade design had superior results compared to our
second blade design.
Our first blade design had a mean current of 234.45 mA
and mean potential of 1.891 V.
Our second blade design had a mean current of 139.0 mA
and a mean potential of 1.169 V.
Tables
Blade 1 Mean Potential(V)
Mean Current(mA)
Mean Power(mW)
Efficiency(%)
Test 1 1.891 236.2 446.65 21.89
Test 2 1.856 232.7 431.89 21.89
Blade 2 Mean Potential(V)
Mean Current(mA)
Mean Power(mW)
Efficiency(%)
Test 1 0.9708 115.7 112.32 26.49
Test 2 1.169 139.0 162.49 26.49
Answer to Hypothesis
Our hypothesis was mildly correct, but there were a few
flaws.
Firstly, the more torque you give your turbine, they more
drag it will experience.
Secondly, by minimizing drag too much, it will cause the
blades to accelerate at a very fast pace causing the turbine
to become unstable.
Recommendations for Future Work
If we had more time, possible things we would do would be:
1. Test out different blades.
2. Make them out of different materials. (Ex. Balsa)
3. Adding different coverings. (Ex. Fabric)
4. Smoothing the edges of the blades.
5. Test the turbine from different distances from the wind source.
Citations
http://learn.kidwind.org/files/webcompetition/WINDSPEED_
2012.pdf
https://vimeo.com/51537100
http://learn.kidwind.org/files/manuals/ADVANCED_BLADE_DESIGN_MANUAL.pdf
Thank You For Listening