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