The purpose of this experiment was to determine which
size and number of wind turbine blades would produce the most electricity.
Air pollution is important to me. I am interested
in wind turbines as alternative energy; this experiment will hopefully
improve the current wind turbines to produce more electricity.
The information gained from this experiment will help
people avoid polluting the air by using wind turbines instead of gas generators,
which pollute the air.
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My hypothesis is that the wind turbine with six blades
and the largest blade will produce the most electricity.
I base my hypothesis on a helpful book American Windmills
which has several windmill designs and I think that the bigger the blade,
the more electricity produced.
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The constants in this study were
The manipulated variable was the number and size of the wind
Speed of the fan for “creating wind”
Shape wind tunnel
Voltmeter used for measuring electricity
Environment the tests were measured
The responding variable was electrical out-put from the
generator hooked to the windmill.
To measure the responding variable I used a voltmeter.
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Board A and C (55-42cm. card board small end in the
center of one end)
Board B and D (55-32 card board small
end in the center of one end)
ply wood board (15-15cm)
ply wood board (5-5cm.)
1.25 diameter dowel
58-32 cardboard piece
58-30 cardboard piece
Propellers (3-4cm. balsa wood)
Propellers (3-8cm. balsa wood)
Propellers (3-12cm. balsa wood)
Drill with 1/4 bit and a 1/16 bit
Rubber corks cir. (6cm.)
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Build A Wind Tunnel
1. Connect board A to board B, and B to C, and C to D,
and D to A with he small ends together.
2. Tape the large of the funnel to the fan.
3. Duct tape the small end of the funnel to the wine
4. Take the two 68cm. by 24cm. and duct tape it to the
68cm. by 32cm. to form a geometric rectangle
5. 11cm. from the wine box, on the left side of the tunnel,
cut a vertical slit 3 cm. for the top and bottom.
6. Repeat step five, but make the slit 62cm. from the
7. cm. from the top and 11cm. from the wine box, make
a third slit 51cm. long.
8. Repeat step six, but make the slit 3 cm. from the
9. Duct tape the Saran Wrap evenly over the hole in the
side of the tunnel and tape it down
10. Take the stand pieces and duct tape them together
to form a cube. (A tub the right size works to)
11. Tape the stand 10cm. from the end of the tunnel using
Build A Wind Turbine
12. Lightly hammer in a nail in the center of the 15-15
13. Drill a hole with a 1/16inch bit about two cm. down.
14. Stick the small hole in the dowel on to the point
of the nail.
15. Continue hammering the nail into the dowel.
16. Place the motor on the edge of the 5-5 with the shaft
sticking out. Screw the motor in place.
17. Remove the motor from its stand.
18. Repeat steps 12-14 but with the 5-5.
19. Return the motor to its stand.
20. In the first rubber cork drill four holes exactly
across from each other.
21. In the second rubber cork drill six holes exactly
across from each other
22. In the exact center of the cork, using the drill
press, drill a 1/16 of an inch 1.5 cm. in the cork.
23. Stick the shaft of the motor in the center of the
24. Mark the small dowel in 1cm. increments. Make
36 of he lines.
25. Cut a vertical slit to the first line with the band
saw in the end.
26. Then cut along the second line.
27. Repeat step 25 and 26 until there are 18 pieces
28. Insert the dowel pieces in the propeller’s ends.
29. Hook up the voltmeter to the motor.
Do the Experiment
30. Insert two of the 3x4 propellers in the first cork
with four holes across from each other.
31. Turn on the fan and record the reading from the volt
32. Insert three 3x4 propellers in the second cork evenly
33. Repeat step 31.
34. Insert four 3x4 propellers in the first cork.
35. Repeat step 31.
36. Insert six 3x4 propellers in all of the holes in
the second cork.
37. Repeat step 31.
38. Repeat steps 23-39 with the 3x6 and the 3x8.
39. Repeat steps 31-39 two more times.
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The original purpose of this experiment was to test the
size and the number of the blades against electrical out put.
The results of the experiment were that on average the
3x8 with four blades produced The most electricity. The 3x6 blade
tests were in the middle of the 3x8 and the 3x4. In the average bars
in my graph it shows that the six bladed was the one that produced the
least amount of electricity. The next was the two bladed, three bladed,
and the four bladed.
Here is my Graph
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My hypothesis was that the longest and the most number
of blades would produce the most electricity.
The results indicate that this hypothesis should be rejected.
Because of the results of this experiment, I wonder if vertical axis wind
turbines produce more electricity than horizontal axis turbines.
If I were to conduct this project again I would made
a bigger wind tunnel and use a more powerful fan so I could test more sizes
of blades and styles of wind turbines.
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Wind turbines are machines that generate electricity.
They produce no pollution but they also have down sides. Wind turbines
are a great way to get energy without pollution.
History of wind mills and wind turbines
Wind mills date back to the days of the Persians
in 7th century A.D. They were originally used for pumping water for
livestock or for grinding grain into flour. Windmills were used throughout
Europe and parts of Asia. The Dutch are famous for their windmills.
The Dutch built a great wall out in the sea and make something like a lake.
Windmills were used to pump the water out, and dry land was formed.
The pilgrims at Cape Cod built the first American
windmill in 1663. Many other windmills were built in the New England
colonies, most were built on Long Island. When the wind was not turning
the blades, if the blades were at a certain angle, it meant something like
a death, birth, sickness or party.
Early American windmills had three main levels.
The first level held grain that had been ground. The second level
had several gears and the third level had grain that not been ground and
the millstone to grind the grain. During the westward expansion,
pioneers built windmills for pumping water for their live stock.
Windmills were very heavy and when the pioneers would move the windmills
were extremely hard to move. Many men tried to build a sturdy lightweight
windmill. Daniel Hallday and John Burnham built a wood windmill and
it looked like a skeleton. The propeller had about many blades. They
needed extra strong wind turbines because of the prairie winds that swept
over the vast land. O. Perry, an inventor built a light metal windmill
and then he hired L. W. Noyes to sell them for him. In the early
West, 6,200,000 windmills were built. To day, windmills are used
mainly for decorations on ranches and old farms. They are not used
for grinding grain because people can buy flour at the store.
Wind turbines are windmills that generate electricity.
Wind turbines produce electricity with no pollution. There are many
styles of wind turbines. There are vertical axis and horizontal axis turbines.
When most people think of a wind turbine, they think of horizontal axis
turbines. Vertical axis wind turbines are different in many ways.
They do not have to have a swivel in order to catch the wind. The
turbines can produce electricity with less wind than horizontal axis generators.
There are also problems with wind turbines. Birds
fly in the blades and they are slaughtered. Patterns have been put
on the blades to make them more visible. Sound is another problem.
Wind turbines produce a lot of noise. Most of the wind farms are
out in the desert and this has helped a lot with that problem. They
also interfere with television and radio reception. This poses a
big problem and people do not like these problems, they just want to get
The first wind turbine was erected in Russia in
1931. The second was built in 1941 in Vermont on a hill called “Grandpa’s
Knob.” It was the largest windmill built in the world. One
part broke and it was not replaced. It was finally replaced after
World War II. The third wind turbine was constructed in the Orkney
Islands in 1954.
Future of Wind Turbines
The newest style of windmill is the vertical axis
or Darrius. They look like a giant eggbeater. There are many
test sites in Canada and they have made many contributions to the science
of wind power. These new wind turbines produce more electricity than
horizontal axis wind turbines do. They are more efficient than the
old style. Computers have also helped in the designing of the new
Wind Turbines have a long history and the date
back to the ancient times. They have been used through history and
they are still in the process of developing. Windmills and wind turbines
are both an old and new energy sources.
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Cosner, Sharon, “American Windmills, ”David McKay Company Inc.,
Gary, Chandler and Kevin Graham, “Alternative Energy Sources,”
Whiteside Ltd., 1996
Mike Eisele, "Which Blade Variable Has the Greatest Effect on Windmill
Efficiency," [Online] Available at http://www.selah.k12.wa.us/SOAR/SciProj99/MikeESciProj.html
Eric Jenkins, "Which Windmill Blades Angle is Most Efficient," [Online]
Available at http://www.selah.k12.wa.us/MS/SciProj98/8TH/EricJ/WINDMILL.HTML
Manwell, James E. “Windmill” Encarta 98
McDonald, Lucile “Windmills New and Old Energy Source” Eliever-Dutton
Publishing Co. Inc.
Visich, Marian Jr. “Turbines” World Book Encyclopedia 1995 v.19 pg.
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