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PURPOSE
The purpose of this experiment was to determine
which windmill blade sizes, shapes, and angles were most efficient at producing
an electrical current from a generator.
The information gained from this experiment will
help windmill designers and people in rugged areas where the power lines
do not reach to determine the optimum size, shape, and angle of windmill
blades used to produce electricity.
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HYPOTHESIS
I believe that a trapezoid shaped blade at 75 degrees
with the largest surface area will generate the greatest amount of electricity
compared to the square, triangle, or rectangular shapes.
I base my hypothesis on internet research and literature
that I have read.
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EXPERIMENT
DESIGN
The constants in this study were:
* Same DC amp meter
* Same windmill
* Same generator
* Same fan (wind generator)
* Same electricity generator
* Same wind speed
* Same fan distance (1 meter) from blades
The manipulated variables are the shape, size (blade
area), angle, and length of the blades.
The responding variable was the electrical output
of the generator attached to the windmill. It was measured as milliamps
on an amp meter.
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MATERIALS
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Quantity
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Item Description
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1
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Windmill
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1
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Amp Meter
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1
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Fan (wind producer)
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1
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Tape Measure
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1
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Electrical Motor (electrical generator)
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24
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Blades shaped as a square. Eight, each
with an area of 12.25cm2; eight, each with an area of 49cm2; and eight,
each with an area of 98cm2.
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24
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Blades shaped as a trapezoid. Eight,
each with an area of 12.25cm2; eight, each with an area of 49cm2; and eight,
each with an area of 98cm2.
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24
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24 Blades shaped as a rectangle. Eight,
each with an area of 12.25cm2; eight, each with an area of 49cm2; and eight,
each with an area of 98cm2.
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24
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Blades shaped as a triangle. Eight, each with
an area of 12.25cm2; eight, each with an area of 49cm2; and eight, each
with an area of 98cm2.
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PROCEDURES
1. Build a windmill out of an erector set, and
place it on a piece of wood. The piece of wood acts as the base of the
windmill. Attach a motor (1.5 volts) to the erector set with a pulley system
connecting the windmill to the motor. The output leads from the motor are
hooked to a amp meter to measure the milliamps.
2. Cut out 24 blades from mat board in each of
these shapes/sizes: trapezoid, triangle, rectangle, and a square at 24.5cm2,
49cm2, and 98cm2 (eight of each).
3. Place the fan exactly 1 meter from the blades
of the windmill.
4. Place eight trapezoid blades each with an area
of 98cm2 on windmill hub.
5. Set the angle of the blades on the windmill
hub to 75 degrees with 0 degrees being perpendicular to the fan blades.
6. Turn the voltmeter to DC milliamps.
7. Turn the fan on high.
8. Read the voltmeter and record the amount of
electricity produced in milliamps.
9. Repeat steps 4-8 using eight of the trapezoid
blades each with an area of 12.25cm2 and 49cm2.
10. Repeat steps 4-8 using eight each of the triangle,
rectangular, or square blades at 12.25cm2, 49cm2, and at 98cm2.
11. Repeat steps 4-10 setting the angle of the
blades on the windmill hub to 45 degrees and 60 degrees.
12. Enter recorded data into a spreadsheet and
create graphs.
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PROJECT LOG
Pre-Experiment Log
October 1, 1999 50 min.
I looked at topics for my science project
and decided to do a continuation of last years science project.
October 2, 1999 120 min.
I started to look up information on the
internet.
October 9, 1999 120 min.
I looked up information on encyclopedias.
October 16, 1999 60 min.
I looked up information on encyclopedias
and the internet.
October 19, 1999 50 min.
I perfected my science project topic and
started to look up information for my research report.
October 23, 1999 10 min.
I looked for websites to get information
off.
October 30, 1999 120 min.
I looked at the websites that I sited.
November 2, 1999 30 min.
I looked up information on the internet.
November 6, 1999 20 min.
I started to take down notes for my research
report,
November 12, 1999 20 min.
I looked up information on windmills in
the electronic encyclopedias.
November 20, 1999 30 min.
I looked up information in the SIS library.
December 7, 1999 120 min.
I looked up information on the internet
and typed up part of my procedures.
December 14, 1999 30 min.
I continued looking up information on encyclopedias
and the internet.
December 16, 1999 20 min.
I continued to type my procedures.
December 19, 1999 20 min.
I finished a rough draft of my procedures.
December 30, 1999 125 min.
I started to build my windmill.
January 1, 2000 200 min.
I finished building my windmill and tested
it.
January 3, 2000 40 min.
I worked on making blades for my windmills
and got information off the internet.
January 4, 2000 72 min.
I made the trapezoid and triangle blades
with a total area of 49cm2.
Experiment Log
January 6, 2000 120 min.
I did my final experiment and collected
all the data possible that I could collect. Before starting
the experiment I made sure that all of the nuts'n'bolts were
tight. I followed all procedures and took care while using the fan.
First I used every blade size and blade shape at the angle
75 degrees. I followed steps 4-8, after turning on the fan
I recorded the results. Next I used every blade size and shape at
the angle of 60 degrees. I followed steps 4-8, after turning
on the fan I recorded the results. Then I used every blade
size and shape at the angle of 45 degrees. I followed
steps 4-8, after turning on the fan I recorded the results.
Post-Experiment Log
January 17, 2000 150 min.
I finished the rough draft of my research
report and bibliography.
January 19, 2000 20 min.
I started to type the results from in a
data spreadsheet.
January 23, 2000 150 min.
I started to put my journal together.
February 1, 2000 120 min.
I am still puting my journal together.
February 2, 2000 30 min.
I am still puting my journal together.
February 3, 2000 60 min.
I am still putting my journal together.
February 5, 2000 30 min.
I started to finalize my journal.
February 6, 2000
I started to finalize my project log.
February 7, 2000
I finalized my pre-experiment and Experiment
log.
February 8, 2000 120 min.
I finished my journal.
February 9, 2000 20 min.
I cut out my things to put on my display
board.
February 10, 2000
I started to paste things onto my display
board.
February 11, 2000 10 min.
I finished my display board.
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RESULTS
The purpose of this experiment was to determine
which blade sizes, shapes, and angles on a windmill were most efficient
at producing an electrical current from a generator.
The results of this experiment were that the all
blades with an area of 98cm2 produced the maximum current of electricity
at a blade angle of 75 degrees with zero degrees being perpendicular with
the fan blades. Of all the blades at 75 degrees and with an area
of 98cm2, the trapezoid blade was more efficient at producing an electrical
current than the triangular, rectangular, and square blades. As the
angle of all the blades declined from 75 degrees to 60 degrees and then
to 45 degrees, the production of electricity declined. At the 60
degree angle, the triangular blades with a surface area of 98cm2
produced a greater amount of electricity than the other three blade shapes.
However, at the 45 degree angle the square blades with a surface are of
98cm2 produced the most electricity than the other three blade shapes.
Every blade shape with an area of 12.25cm2 did
not produce any electricity at any blade angle, because the surface area
was not large enough to spin the generator. All the blade shapes
with an area of 49cm2 created electricity at all angles except for
the trapezoid blades at 75 degrees. It appears that the 49cm2
trapezoid blades did not turn the windmill due to surface area not being
big enough. However, at 98cm2 surface area, trapezoid blades produced
more electricity than the square, rectangular, or triangular shapes.
See the table and graph below.
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CONCLUSION
My hypothesis was that a trapezoid shaped blade
at 75 degrees with the largest surface area would generate the greatest
amount of electricity compared to the square, triangle, or rectangular
shapes. My hypothesis should be accepted because the greatest amount
of electricity was produced with the trapezoid blades with an area of 98cm2
at 75 degrees.
My experiment demonstrated, that even though my
hypothesis was correct, the other blade angles at blade surface areas greater
than 98cm2 may actually be better shapes for a windmill than the trapezoid
shape. This would have to be something proven in doing more experimenting
with windmills. The windmill that was used in this experiment was not large
enough to handle blade areas greater than 98cm2.
With the knowledge I gained from this experiment
and if I were to conduct this project again, I would construct a windmill
with a larger wind radius so that I could test greater surface area blades.
I would also do multiple tests and I would also verify the wind speed.
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RESEARCH
REPORT
Introduction
Windmills historicaly only did four things:
pumped water, ground grain, produced electricity, and just sat for decoration.
Windmills were invented in Persia in the 5th century AD. In the early
years of the 1900s, there were more than 700 different kinds of water
pumping windmills. In the 1930s a windmill that stood 8 ft. tall cost
$25.00. Today that windmill would cost $1,455.00. Today there are
only two types of windmill which are vertical-axis machines and horizontal
axis-machines. Some people say that windmills went out of fashion
in the 1940s.
Modern Windmills
Windmills today are called turbines which are
powered by wind. Modern windmills are mostly used for creating electricity
especially in rugged areas. The windmill blades are set at an angle
so the wind will catch the blades and turn them. Today over 80% of the
windmills spin in California, 13% in Denmark, and 2.3% in Hawaii.
History Of Windmills
Windmills were discovered at the end of the
Roman period. The first windmills were used to pump water for irrigation
or grind grain in Persia around 5th century AD. By the 12 century
AD, windmills were found throughout Europe. The Dutch built windmills
out of wood and canvas. For centuries the Dutch had relied on windmills
for energy and by the 19th century the Dutch had built over 9000 windmills.
In the Netherlands people used windmills to drain water from fields, or
to mill grain. In the 1900s Americans used windmills to pump water.
In the late 1980s more than 30 different companies were manufacturing
wind machines. In studies the smaller windmills on the smaller platforms
were proven more successful than the bigger windmills on the bigger platforms.
Big windfarms were found to have disruptions such as noise pollution and
disruption of radio or television. The only way that the wind farms
create a disruption in habitat are when trees need to be cut down.
Denmark
By 2030 100% of the power in Denmark is expected
to come from windmills. It will be the largest investment ever made
in windmills. Right now engineers and scientists are finding ways
to make offshore foundations strong enough so that the windmills will be
able to with stand the force of waves and currents crashing against them.
Kinds of Windmills
Today there are only two kinds of turbines,
horizontal-axis machines and vertical-axis machines. There is one
more windmill blade that has the principles of an airplane wing to make
rotation. They are driven by wind simply striking the blades.
An example of the horizontal-axis machines are the multi-bladed windmills
of the US Prairies. In the 1920s George Darrieus a French inventor,
invented an efficient wind turbine. This wind turbine was called
the, "Darrieus Wind Turbine". It had the characteristics of an eggbeater
with only two or three carved blades hooked to the vertical shaft.
It would catch the wind from all directions unlike most windmills.
Propellers
Propeller- A propulsion device usually used
on ships and planes. A propeller
is a series of blades on a hub that is mounted
on an engine-driven shaft (or wind). The rotation of blades in water
or air produces a forward thrust. In the 1920's George Darrieus, a French
inventor, invented an efficient wind turbine. The Mod-2 a government
funded test windmill has 91m (300 ft) long propellers. It is 25 stories
tall.
Summary
The windmill is an invention that dates back
to the end of the roman Empire. There are only two types of windmills,
horozontial-axis and vertical-axis. Understanding windmill design
to improve power is important for the future, people will be running off
windmills because windmills do not pollute the earth and only create a
diruption for the environment if we have to cut down treees.
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BIBLIOGRAPHY
Alexander Llyin, Mary. "Windmill," The World Book
Encyclopedia, 1999
Danish Wind Turbine Manufacturing Association,
[Online]
http://www.windpower.dk/tour/rd/monopile.htm,
January 3, 2000
Landris, Fred. "Bernoullis Principle," Encarta,
2000.
"Power," Microsoft Encarta, 2000.
"Powered By Wind," The World Book Encyclopedia,
1998.
"Windmills," Grolliers Interactive Encyclopedia,
1998.
Settles, Gary S. "Power," Grolliers Interactive
Encyclopedia, 1998.
"Windmill," Microsoft Encarta, 1999.
Mr. Brown's MYstical Science Page [Online] Http://www.selah.k12.wa.us/LINKS/olderlinks.html |
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