Ram Air Turbine (RAT)
Classroom Wind Turbine
Part 1: Air Power II
Some aircraft are equipped with a ram air turbine or RAT. The RAT consists of a
propeller that is spun by the high-speed air flowing past the aircraft. The spinning
propeller powers a turbine that provides the emergency electricity needed to keep
critical systems running, such as hydraulics, flight controls, and key avionics. In normal
flight, the entire assembly is folded up and stored in the aircraft fuselage or wing.
A wind turbine is the modern advancement of the windmill. Instead of using the wind to
lift water or move heavy rocks to grind seeds, wind is used to turn an electrical
generator to make electricity. Sometimes, students mistake our model wind turbines for
a fan. While a fan uses electricity to produce wind, a wind turbine uses the wind to
produce electricity!
Efficient turbine blades are a key part to generating power from a RAT or wind turbine.
The blade shape, size, pitch and number are important elements in developing electrical
voltage. Blades that are poorly shaped, sloppily made, too small, too large, too few, or
too many will reduce the efficiency of a wind turbine.
The objective of this sortie is to compare turbine blade types to determine which blade
shape and number of blades develops the most voltage. A turbine stand, motor, hub
and four types of fan blades, and a voltmeter will be provided to student teams. Teams
will measure the length and width of sample blade type and calculate the surface area
of each blade set. Then they will test blades of the same shape by changing the number
of blades attached to the turbine hub. The fan air speed will be varied as well. Voltage
generated by the turbine with the selected blades and blade number will be observed
and recorded on a data collection instrument.
Students will analyze the recorded data and draw conclusions about the area, number,
shape of turbine blades and fan speeds that are most efficient at developing the most
voltage.
Property of Engineers For America STEM Initiative and not to be copied in part or whole without permission.
1
February 2010
Code: SC.H.1.3.4, SC.C.2.3.1, SC.6.N.1.1, SC.6.N.1.2, SC.6.P.11.1, SC.P.13.1,
SC.7.P.10.3, SC.7.P.11.2, SC.7.11.3, MA.6.S.6.2
Location Coordinates: (
,
)
Materials in sortie box
Box labeled Air Power II
Inventory sheet is located on the box lid.
Boxed Materials include:
5 turbine test stands
5 voltmeters
6 sets of turbine blades
6 stopwatches or event timers
5 three-speed fans
5 clipboards
5 sets of test leads
6 bungee cords
12 30cm rulers
6 extension cords
3 three-way cord splitters
6 power strips
Materials you bring:
1ps pencils
1ps data collection sheet
Pre Visit Instructions
Review the terminology of wind turbines by pointing out the various parts by name.
Pre Task Instructions
1. Divide students into teams of four students.
2. The duties required are one student as data collector, two as the test engineers
and one as a timekeeper. The timekeeper will keep track of time so the team stays on
schedule and completes all required test trials. The timekeeper will use a stopwatch or
an event timer to keep track of trials and sortie time.
3. Assemble sortie apparatus. Each student station must be set up as shown in diagram
1.
Property of Engineers For America STEM Initiative and not to be copied in part or whole without permission.
2
February 2010
Fan
Turbine blades
Fan Airflow
Turbine generator
bungee cord
PVC Turbine stand
Voltmeter
Fan mount
Diagram 1
a. Assemble PVC turbine stand.
b. Place the fan on the fan mount and point the fan into the turbine.
c. Use bungee cord to fasten the fan to the fan mount.
d. Place the test leads by the voltmeter. The black voltmeter test probe wire should
be connected to the “COM” (center) plug of the voltmeter. The red test probe wire
should be connected to the “VmA” (right) plug of the voltmeter.
e. Make certain the switch on the fan is in the “off” position.
f. Place the container with the four types of turbine blades (alpha, bravo, charlie, and
delta blades with dowels attached) on the table by the fan.
g. Place the rulers by the sample blade types.
h. Place the four sample blades (blades without wooden dowels) on the table by the
fan.
i. Plug box fan into the power strip.
j. Plug the power strip into the extension cord and the extension cord into one of the
three-way splitters.
Safety Briefing
4. Remind students:
a. Turn the knob on the hub to loosen the blades dowels. Retighten the knob to
tighten the dowel blades.
b. Do not twist the blades without loosening the hub knob.
c. Students will not attempt to poke anything into the fans.
d. Students will not attempt to poke anything into the fans or turbine blades.
e. Turbine blades are very fragile. Handle blades carefully.
Property of Engineers For America STEM Initiative and not to be copied in part or whole without permission.
3
February 2010
f.
g.
h.
i.
j.
Do not over tighten the turbine hub tightener.
Students will only use the switch on the power strip to turn fans off and on.
Use caution when the fans are in operation.
Never stop turbines fan blades with fingers.
If you break anything, do not attempt to collect broken pieces. Instead notify the
sortie facilitator.
5. Students will prepare their data collection instruments to record the data they collect
during their sortie activity.
6. Review the four types of blades with students. The following dimensional data is
provided for the teacher’s use. Do not supply this information to students. Students will
be responsible to measure the different blade types and calculate the area of each type.
-Alpha (blue dot) blades are 1.5 X 8 inch rectangles.
-Area per blade: 12 square inches
-Area of four blades: 48 square inches
Bravo (red dot) blades are 3 X 8 inch rectangles.
-Area per blade: 24 square inches
-Area of four blades: 96 square inches
-Charlie (green dot) blades are 1.5 X 16 inch rectangles.
-Area per blade: 24 square inches
-Area of four blades: 96 square inches
-Delta (yellow dot) blades are 2.5 X 16 X .5 X 16 inch rectangles.
-Area per blade: 24 square inches
-Area of four blades: 96 square inches
7. The turbine hub has openings to attach 12 blades. Blades should be attached with
the dowels on the side away from the fan.
8. Remind students to attach blades symmetrically. That is:
a. When using two blades install the blades at the 12 o’clock position and the 6
o’clock position.
b. For three blades, attach one at the 2 o’clock position, six o’clock position and
the ten o’clock position.
c. For four blades, blades should be at 12 o’clock, 3 o’clock, 6 o’clock and 9
o’clock, respectively.
Property of Engineers For America STEM Initiative and not to be copied in part or whole without permission.
4
February 2010
Task
1. The two test engineers will oversee the other team members measure the four
sample blades and calculate the area of each blade. Each student should record this
data on their SLOF. This data will be used later.
2. The turbine stand will have two wires extending from the bottom support pipe. One
wire will be marked positive (+) and the other wire will be marked negative (-).
3. Direct students to use a test lead to connect the red probe (positive) of the voltmeter
to the wire marked positive (+) of the wind turbine stand.
4. Direct students to use the other test lead to connect the black probe (negative) of the
voltmeter to the wire marked negative (-) of the wind turbine.
5. Confirm the voltmeter is turned on. Use the mode switch to set the voltmeter to the
20 volt scale (white scale on left side of voltmeter face) position.
6. Gently spin the blades of the wind turbine to confirm that a positive voltage reading is
seen on the voltmeter. If the voltmeter indicates a negative voltage, reverse the test
lead connections from the turbine to the voltmeter.
7. Direct students to begin with an Alpha (blue dot) type fan blades. Attach the number
of blades to turbine hub as directed by the SLOF. The SLOF will direct student teams to
use 2, 3, 4 and blades and test them at fan speeds 1 and 3 for 30 seconds each. Time
permitting; students may also test each blade number at fan speed 2 for 30 seconds.
The following is an excerpt from the SLOF data collection instrument (Part 3). Refer this
excerpt as you review the procedure for the trials.
Trial
Number
of Blades
Blade
Type
1
2
3
4
5
6
2
3
4
2
3
4
A (blue)
A (blue)
A (blue)
B (red)
B (red)
B (red)
1
1
1
1
1
1
Fan
Speed
2
2
2
2
2
2
Speed
1 VDC
Speed
2 VDC
Speed
3 VDC
3
3
3
3
3
3
8. Sortie trial description.
a. For “Trial 1” use two “Alpha (blue dot)” blades on “fan speed 1” for 30
seconds. One test engineer will install the blades and the second test
engineer with control the switch on the power strip. The data collector will
Property of Engineers For America STEM Initiative and not to be copied in part or whole without permission.
5
February 2010
read and record the highest voltage reading on the voltmeter under the
“volts, direct current (VDC) speed 1” column. Record all voltages to the
nearest tenth of a volt (e.g. 2.4 vdc). The timekeeper will watch the time so
ensure each blade is checked for 30 seconds on each speed and the team is
staying on time.
b. To complete “Trial 1” the test engineer will change the fan speed to 3 for 30
seconds. The second test engineer will be applying and removing power to
the fan by suing the switch on the power strip. The data collector will record
the highest voltage read on the voltmeter under the “VDC speed 3” column.
If teams have been permitted to do so by the sortie facilitator, teams may
also test the blades at fan speed 2. The timekeeper should be tracking all fan
trials (30 seconds) and making sure the teams do not exceed the overall
sortie time. Continue in this manner and go on to trial 2.
c. For “Trial 2” use three “Alpha (blue dot)” blades on “fan speed 1” for 30
seconds. Record the highest voltage read on the voltmeter under the “VDC
speed 1” column.
d. To complete “Trial 2” change the fan speed to 3 for 30 seconds. Record the
highest voltage read on the voltmeter under the “VDC speed 3” column. Time
permitting; teams may also be permitted to test the blades at fan speed
2.
e. To begin “Trial 4” change to two “Bravo (red dot)” blade types with the “fan
speed 1” for 30 seconds.
f. Continue until all the trials on the SLOF you selected for your teams have
been completed. Be certain you determine the trials you want your teams to
conduct. Before they begin.
9. Follow the SLOF instructions to complete the trials to complete the task. Remind
students to change blade types and blade number(s) as required.
Optional Step
Direct students to use a laminar air flow fan after using the turbulent air fan. Repeat the
trials. Compare the data of the voltage generated with one fan versus the other.
Post Task Instructions
1. Direct students to return the sortie station to its original the condition (the condition it
was in when they arrived).
2. Remove all blades from the turbine hub.
Property of Engineers For America STEM Initiative and not to be copied in part or whole without permission.
6
February 2010
3. Disconnect the test leads from the voltmeter cables.
4. Remind students to turn the voltmeter mode switch to the “OFF” (12 o’clock position
of the voltmeter face). This conserves battery life.
5. Direct students to collect their personal items and prepare to move to the next sortie.
Follow-On Activities
1. Ask students if their data reveals anything to them about turbine blades.
2. Ask students which turbine blades and blade numbers were most efficient.
3. Ask students which turbine blades and blade numbers were least efficient.
4. Ask students for other turbine blade shapes, numbers and combinations they
would like to investigate further.
5. Ask students for their turbine blade shape ideas.
6. Ask students for their turbine blade material ideas.
7. Forward suggestions to the OCSD Science Specialist for consideration for inclusion
in future sorties.
Property of Engineers For America STEM Initiative and not to be copied in part or whole without permission.
7
February 2010
Sortie Lima: “Air Power II”
New Generation Standards for Science and Math: Grade 6-8
MA.6.S.6.2: Select and analyze the measures of central tendency or variability to
represent, describe, analyze, and/or summarize a data set for the purposes of
answering questions appropriately.
SC.6.N.1.1: Define a problem from the sixth grade curriculum, use appropriate
reference materials to support scientific understanding, plan and carry out scientific
investigation of various types, such as systematic observations or experiments, identify
variables, collect and organize data, interpret data in charts, tables, and graphics,
analyze information, make predictions, and defend conclusions.
SC.6.N.1.2: Explain why scientific investigations should be replicable.
SC.6.P.11.1: Explore the Law of Conservation of Energy by differentiating between
potential and kinetic energy. Identify situations where kinetic energy is transformed into
potential energy and vice versa.
SC.6.P.13.1: Investigate and describe types of forces including contact forces and
forces acting at a distance, such as electrical, magnetic, and gravitational.
SC.6.P.13.3: Investigate and describe that an unbalanced force acting on an object
changes its speed, or direction of motion, or both.
Property of Engineers For America STEM Initiative and not to be copied in part or whole without permission.
8
February 2010
Part 2: Air Power II
Some aircraft are equipped with a ram air turbine (or RAT). The RAT consists of a
propeller that is spun by the high-speed air flowing past the aircraft. The spinning
propeller powers a turbine that provides the emergency electricity needed to keep
critical systems running, such as hydraulics, flight controls, and key avionics. In normal
flight, the entire assembly is folded up and stored in the aircraft fuselage or wing.
A wind turbine is the modern advancement of the windmill. Instead of using the wind to
lift water or move heavy rocks to grind seeds wind is used to turn an electrical generator
to make electricity. Sometimes, students mistake our model wind turbines for a fan.
While a fan uses electricity to produce wind, a wind turbine uses the wind to produce
electricity!
Efficient turbine blades are a key part to generating power from a RAT or wind turbine.
The blade shape, size, pitch and number are important elements in developing electrical
voltage. Blades that are poorly shaped, sloppily made, too small, too large, too few, or
too many will reduce the efficiency of a wind turbine.
The objective of this sortie is to compare turbine blade types to determine which blade
shape and number of blades develops the most voltage. A turbine stand, motor, hub
and four types of fan blades, and a voltmeter will be provided to your team. You and
your team will measure the length and width of the sample blade types and calculate
the surface area of each blade set. Then you will test blades of the same shape by
changing the number of blades attached to the turbine hub. The fan air speed will be
changed to different speeds as well. Voltage generated by the turbine with the selected
blades and blade number will be observed and recorded on a data collection
instrument.
You and your team will analyze the recorded data and draw conclusions about the area,
number, shape of turbine blades and fan speeds that are most efficient at developing
the most voltage.
Location Coordinates: (
,
)
Pre Task Instructions
1. The sortie facilitator will divide you into teams of four students.
2. The team duties require one student as data collector, two as the test engineers
and one as a timekeeper. The timekeeper will keep track of time so the team stays on
schedule and completes all required test trials. The timekeeper will use a stopwatch or
event timer to keep track of trial and sortie time.
3. Each student station must be set up as shown in diagram 1. Look over this set up
and ask any questions you have.
Property of Engineers For America STEM Initiative and not to be copied in part or whole without permission.
1
February 2010
Fan
Turbine blades
Fan Airflow
Turbine generator
bungee cord
PVC Turbine stand
Voltmeter
Fan mount
Diagram 1
a. When told to do so, measure the blade samples (A, B, C, and D) with a ruler and
calculate the area of each. Record the data on page one of your SLOF (data
collection sheet). This data will be used later.
b. Locate the two test leads. The two leads will be used to connect the positive (+)
and negative (-) wires of the turbine to the voltmeter test probes.
c. The black multimeter test probe wire should be plugged into the “COM” (center)
plug of the voltmeter. The red test probe wire should be plugged into the “10ADC”
(left) plug of the multimeter.
d. Use the test leads to connect the multimeter probes to the turbine wires. The red
voltmeter test probe should be connected to the positive (+) turbine wire. The
black voltmeter test probe should be connected to the black (-) turbine wire.
e. Make certain the switch on the box fan is in the “off” position.
f. Locate the boxes with the four types of turbine blades (alpha, bravo, charlie, and
delta) on the table by the fan.
g. Confirm the box fan is plugged into the power strip and the power strip is in the
“off” position.
h. The power strip is connected into the extension cord and the extension cord into
one of the three-way splitters. You will use the switch on the power strip to turn the
fan off and on.
Safety Briefing
4. Remember students:
a. Turn the tightener knob on the hub to loosen the blades dowels. Retighten the
knob to tighten the dowel blades.
Property of Engineers For America STEM Initiative and not to be copied in part or whole without permission.
2
February 2010
b.
c.
d.
e.
f.
g.
h.
i.
j.
Do not twist the blades without loosening the hub tightener knob.
Students will not attempt to poke anything into the fans.
Students will not attempt to poke anything into the fans or turbine blades.
Turbine blades are very fragile. Handle blades carefully.
Do not over tighten the turbine hub tightener.
Students will only use the switch on the power strip to turn fans off and on.
Use caution when the fans are in operation.
Never stop turbines fan blades with fingers.
If you break anything, do not attempt to collect broken pieces. Instead notify the
sortie facilitator.
5. Prepare your data collection instruments to record the data you will collect during the
sortie activity.
Task
1. The turbine stand will have two wires extending from the bottom support. One wire
will be marked positive (or +) and the other wire will be marked negative (or -).
2. Use a test lead to connect the red probe (positive) of the voltmeter to the wire
marked positive (or +) of the wind turbine.
3. Use the second test lead to connect the black probe (negative) of the multimeter to
the wire marked negative (or -) of the wind turbine.
4. Turn multimeter to the “on” position. Use the mode switch to set the multimeter to the
20 volts DC scale (white scale on left side of voltmeter face) position.
4. Gently spin the generator hub of the wind turbine to confirm that a positive voltage
reading is seen on the voltmeter.
5. Select alpha (blue dot) type fan blades. Attach the number of blades to turbine hub
as directed by the SLOF. The SLOF will direct you to use 2, 3, 4 and blades and test
them at fan speeds 1 and 3 for 30 seconds each. Time permitting or if directed by the
sortie facilitator, you may also test the blades at fan speed 2. Be certain you have
permission to test at fan speed 2 before you start.
SLOF excerpt:
Trial
Number
of blades
Blade
Shape
1
2
2
3
A (blue)
A (blue)
Fan Speed
1
1
2
2
VDC
Speed
1
VDC
Speed
2
VDC
Speed
3
3
3
Property of Engineers For America STEM Initiative and not to be copied in part or whole without permission.
3
February 2010
a. For “Trial 1” use two “alpha (blue dot)” blades. The test engineer will
loosen the turbine hub knob and install one blade at the 12 o’clock position
and one blade at the six o’clock position of the hub. Tighten the hub knob. Do
not over tighten.
b. The second engineer will turn the fan speed knob to fan speed 1.
c. Use switch on power strip to turn fan on for 30 seconds. The timekeeper
should keep track of the time required.
d. The data collector should record the highest voltage read on the voltmeter
under the “VDC speed 1” column.
e. To continue “Trial 1” change the fan speed to 3 for 30 seconds.
f. Record the highest voltage read on the voltmeter under the “VDC speed 3”
column.
g. If you have permission to test fan speed 2, select fan speed 2 at this time for
30 seconds.
h. Record the highest voltage read on the voltmeter under the “VDC speed 2”
column.
i. Turn the fan speed to 1 and turn off the fan by using the switch on the power
strip.
j. For “Trial 2” use three “alpha (blue dot)” blades. Loosen the turbine hub
knob. Install one blade at the 12 o’clock position and one blade at the 4
o’clock position and one blade at the 10 o’clock position of the hub. Tighten
the hub knob. Do not over tighten.
k. Select fan speed 1 and turn the fan on by using the switch on the power strip.
l. Record the highest voltage read on the multimeter under the “VDC speed 1”
column.
m. To complete “Trial 2” change the fan speed to 3 for 30 seconds.
n. Record the highest voltage read on the multimeter under the “VDC speed 3”
column.
o. If you have permission to test fan speed 2, select fan speed 2 at this time for
30 seconds.
Property of Engineers For America STEM Initiative and not to be copied in part or whole without permission.
4
February 2010
6. Follow the SLOF instructions to complete the trials to complete the task. Remember
to change blades type, blade number and fan speed as required by the SLOF.
Post Task Instructions
1. Check over your data collection SLOF. It should have entries in each of the assigned
test areas.
2. Return the sortie station to its original the condition (the condition it was in when you
arrived).
3. Remove all blades from the turbine hub.
4. Disconnect the test leads form the voltmeter cables.
5. Return the voltmeter mode switch to the “OFF” (12 o’clock position of the voltmeter
face).
6. Collect personal items and prepare to move to the next sortie.
Property of Engineers For America STEM Initiative and not to be copied in part or whole without permission.
5
February 2010
PART 3 – AIR POWER II
SCIENCE LAB OBSERVATION FORM (SLOF)
Test Engineer(s)___________________________ _____________________________
Timekeeper ______________________ Data Collector: _______________________
1. Procedure - This is what I will do: ________________________________________
______________________________________________________________________
______________________________________________________________________
______________________________________________________________________
2. Prediction - This is what I think will happen: _______________________________
______________________________________________________________________
______________________________________________________________________
______________________________________________________________________
3. Observation - This is what I saw happen: __________________________________
______________________________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
AREA: Blade A
AREA: Blade B
AREA: Blade C
AREA: Blade D
4. Evaluation - This is why I think it happened, and this is what I learned:
______________________________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
Property of Engineers For America STEM Initiative and not to be copied in part or whole without permission.
1
February 2010
PART 3 – AIR POWER II
DATA TABLE 1. Turbine Fan Blade Test
Trial
Number
of Blades
Blade
Shape
1
2
3
4
5
6
7
8
9
10
11
12
13
2
3
4
2
3
4
2
3
4
2
3
4
3
A blue
A blue
A blue
B red
B red
B red
C green
C green
C green
D yellow
D yellow
D yellow
red plastic
Fan Speed
1
1
1
1
1
1
1
1
1
1
1
1
1
2
2
2
2
2
2
2
2
2
2
2
2
2
VDC
Speed
3
VDC
Speed
1
VDC
Speed
3
3
3
3
3
3
3
3
3
3
3
3
3
3
1. Which trial developed the most voltage?
2. What was the highest voltage developed?
3. Which trial developed the lowest voltage?
4. What was the lowest voltage developed?
5. Which blade shape developed the most voltage?
6. What number of blades developed the most voltage?
7. Which blade shape developed the least voltage?
8. What number of blades developed the least voltage?
9. Name at least two other blade factors or characteristics you could investigate to determine if
the turbine could generate more voltage.
10. What was the relationship of the area of each type of blade to the others?
11. Can you draw any conclusions regarding the blade area and voltage generated?
Property of Engineers For America STEM Initiative and not to be copied in part or whole without permission.
2
February 2010
Part 4 - AIR POWER II
SORTIE APPARATUS CONFIGUARTION DETAIL
Power Strips
Fan Direction
Fan
Turbine
Fan Direction
Voltmeter
Diagram 1
1. Connect the three-way splitter to an outlet.
2. Connect an extension cord to one of three splitter outlets.
3. Ensure the power switch is “off” and connect the extension cord to the power strip
on the table.
4. Connect the fan cord to the power strip on the table.
5. Make certain the fan switch is “on.” Students will use the power strip switch to turn
the fans “on” and “off”.
6. Turn the fan “off” with the power switch on the power strip.
Property of Engineers For America STEM Initiative and not to be copied in part or whole without permission.
February 2010
PART 5 – AIR POWER II
TEACHER OBSERVATION / SUGGESTION / REVISION FORM
Teachers who visit the USAF Armament Museum with their students should provide
feedback to the OCSD Curriculum office. This feedback is important in assessing the
quality of the materials and activities for our teachers and students. Teachers may use
this form for recording any observation, making comments, or suggesting revisions and
additions to the activities. Comments may be anonymous but by including identification,
we may contact you to ask for additional details. Identification will also allow us to
advise you whether we need more information to implement your suggestion(s).
Teacher: _____________________________ School:__________________________
Telephone: __________________________
e-mail:__________________________
Date of Visit: ____________________________
Which activity did you enjoy best? __________________________________________
Which activity did your class enjoy best?_____________________________________
Is there an activity you would like to have added to address a NG SSS?_____________
______________________________________________________________________
If necessary, continue Observations, Comments and Suggestions on reverse
Observations:__________________________________________________________
______________________________________________________________________
Comments:____________________________________________________________
______________________________________________________________________
Suggestion(s):_________________________________________________________
______________________________________________________________________
______________________________________________________________________
Overall rating
5
Outstanding
4
Above
3
Average
2
Fair
1
Poor
soriar@mail.okaloosa.k12.fl.us
Property of Engineers For America STEM Initiative and not to be copied in part or whole without permission.
February 2010
KidWind MINI Wind Turbine
Copyright ©2009
®
Kidwind Project ®
800 Transfer Rd. Ste 30B
Saint Paul, MN 55114
http://www.kidwind.org
Children should use this kit only under the close and direct supervision of adults who have familiarized themselves with the safety instructions outlined in this manual. When performing experiments,
keep small children and animals away. This kit contains moveable parts. When in use, be sure to
stand a safe distance away from the moving portions of the kit. Please keep the manual and instructions for future reference and refer to these each time you use the kit.
KidWind MINI Wind Turbine
The KidWind MINI is perfect for demonstrating how a wind turbine generates energy. The
MINI is easy to build and produces enough electricity to power LED bulbs, a small power
output board, and other small load devices (mini water pumps, motors, buzzers, etc).
The KidWind MINI Kit includes the full turbine, a power output board with lights and
sound generator and a pair of clip wires to attach your own electrical devices.
Parts Included
•
•
•
•
•
•
•
•
1/2” PVC “T” Fittings (3) (1 drilled)
1/2” PVC Elbow Fittings (4)
1/2” PVC sections, 1” long (6)
1/2” Blue HDPE Tower, 8” long (1)
PVC Nacelle with generator, LED Bulb, and wires (1)
Blade Set (1)
Power Output Board (1)
Alligator clip cords (2)
(6)
(4)
(3)
(1)
(1 drilled)
Building the Wind Turbine
1. Using (4) 90° PVC fittings, (2) PVC Ts and (4) 1”
PVC pipe sections, construct the two sides of the
PVC turbine base.
2. Fit the parts together without using glue (PVC glue
is really nasty stuff). To make them fit snuggly tap
them together with a hammer or bang them on the
floor once assembled.
3. Next, connect the two sides of the base using the
drilled PVC “T” and two more 1” pipe sections.
Drilled
4. Run the red and black wires from the nacelle (head) through the blue HDPE Tower and
connect the nacelle to the tower.
5. Push the red and black wires through the drilled hole in the PVC “T” at the bottom of
the base. Connect the blue HDPE Tower to this drilled “T”
6.
Push the blades onto the generator drive shaft. The hole on the back of the blade set
will friction-fit onto the drive shaft. This may be a very tight fit, so you may have to
push fairly hard. Be careful not to push too hard, or the generator may slide
backwards in the housing. If you push the blades on too far, the
blades will rub on the PVC housing. Make sure there is some clearance
there for the blades to spin freely.
7. If you need to remove the blades, you can use a screwdriver to “pry”
the blade set off the generator. Use caution not to break a blade.
Setup for Testing the MINI Wind Turbine
It is important to clear your testing area of debris and materials that could block the wind
or be blown away. Place your turbine in front of the fan so that the blades are facing into
the wind.
When you are testing, stand BEHIND your turbine or BEHIND the fan. Do not stand in the
“plane of rotation” of the blades, in case something hits them and flies out.
Some things to note about fan wind that reduce the efficiency. Fans create:
• Highly Turbulent & Rotational Wind— This turbulent fan wind is different from real
wind outside.
• Highly Variable Wind Speed— Wind speed is about 10-13 MPH on high for a $20 circular fan. Wind speeds near the middle will be much different than the edges.
Going Outside?
While you can use your wind turbine outside, you must make sure that you face it into the
wind. This is because this turbine is not designed to YAW (or rotate) to face the wind. If
the wind shifts and the turbine cannot rotate, wind will hit the blades from the sides causing stress and inefficiency. For a challenge, try to adapt your tower to be able to yaw.
Connecting the Turbine to Electrical Devices
The KidWind MINI Turbine can power a variety of electrical devices beyond the included
LED bulb! For more fun experiments, try pumping water with the KidWind mini water
pump, electrolyzing water in a hydrogen fuel cell, or storing energy in a supercapacitor!
All of these accessories can be found in the KidWind online shop.
The turbine will spin COUNTER-CLOCKWISE with the included blade set. When spinning
this way, the red wire is POSITIVE and the black wire is NEGATIVE. This is called the POLARITY of the turbine, and is important for certain electrical devices that are polarized.
For example, if you are charging a supercapacitor, make sure the red turbine wire (+)
goes to the longer lead (+) of the supercapacitor. If you are electrolyzing a fuel cell, connect the red turbine lead to the red input terminal of the fuel cell.
Once your circuit is connected, turn on the fan and the turbine will start pumping out
power to your electrical device!
If you want to know the electrical power output of your wind turbine, you will need a multimeter. This is a very helpful tool for measuring voltage and amperage output.
SAFETY—IMPORTANT (PLEASE READ!)
•
•
•
•
DO NOT TOUCH THE BLADES WHILE THEY ARE SPINNING. They are moving very fast
and will hurt your hand if they hit you.
Do not stand in the “plane of rotation” of the blades (to the side of the blades) in case something hits them and flies off. Stand in front of or behind the turbine.
Wear safety goggles when the turbine is spinning.
Use caution when working with electricity. Although this turbine will not produce enough electricity to shock you, it is important to practice safety with electricity.
KidWind MINI Turbine Experiments
The KidWind MINI was designed to demonstrate wind power technology,
and you can still do some cool experiments!
Changing Wind Speed
Place the turbine about three feet in front of a fan, and turn it on HIGH. What happens when
you turn the fan to MEDIUM or LOW? Does the LED bulb light up at any wind speed?
Now leave the fan on MEDIUM and move your turbine away from the fan by about a foot. Continue moving the turbine away from the fan, one foot at a time, until the LED bulb no longer
works. How far away can you get? Why is the turbine unable to power the light bulb as you
back away from the fan?
Try this experiment with a multimeter to measure voltage. What happens to the voltage as you
move your turbine further from the fan, or slow down the wind speed?
Use the Turbine to Power Other Devices
This turbine can be used to operate other electronic devices besides the attached LED bulb, but
only devices that require very little electricity. For example, the power output board included in
the kit can light bulbs or play music. You can also connect it to another DC motor, which could
spin a small propeller. Or, attach the wires to a multimeter. A multimeter allows you to more
accurately measure how much electrical energy your turbine is producing. KidWind
(www.kidwind.org) also sells other items like water pumps, fuel cells, and battery charging systems that can make your experiments more advanced.
Test Blades
The blades included in the package are designed to be very efficient, but if you want, you can
design your own blades, too. First you will need a hub to attach your blades to the generator.
The 12 Hole Crimping Hub from KidWind is perfect for blade-design experiments. Slide off the
plastic blade set, and replace it with the hub. Design your blades, and glue or tape them to
1/4” dowels. These dowels fit perfectly in the 12 Hole crimping hub.
Now you can do a lot of great experiments by isolating blade variables and examining how they
affect the power output of your turbine. Try these variables to get started: Blade pitch (angle),
blade size, blade shape, number of blades, etc. After you have attached your new blades, try to
light the LED bulb or measure your power with a multimeter. How has the efficiency of your
turbine changed? Try a few blade designs to learn what makes blades more efficient.
The 12 hole crimping hub allows you to use up to 12 blades, so be sure to try some experiments with the number of blades. If you are feeling adventurous try using one blade!
Different Generators
The DC generator in your wind turbine is actually a DC motor that spins using the energy in the
wind. The magnets and wires in the generator transform the energy in the wind into electricity.
By manipulating the strength of the magnets used and coils of wire inside the generator we can
affect the power output. In this kit we provide you with a DC generator. If you wanted, you
could compare this output to a different DC generator that you harvest from some old electronics in your house. Old VCRs, electrical toys and CD players are good places to start finding DC
motors. Do some research on how generators work or electromagnetism to learn more.
Build a MINI Wind Farm (see page 6)
Power in the Wind — A Simple Look
If a large truck or a 250lb linebacker was moving toward you at a high rate of speed, you
would move out of the way, right?
Why do you move? You move because in your mind you know that this moving object has a
great deal of ENERGY as a result of its mass and its motion. And you do not want to be on
the receiving end of that energy.
Just as those large moving objects have energy, so does the wind.
air from one place on earth to another. That’s the motion part.
Wind is the movement of
What is air though? Air is a mixture of gas molecules. It turns out that if you get lots of them
(and I mean lots of them) together in a gang and they start moving pretty fast, they can
definitely give you — a sailboat or a windmill — a serious push. Just think about hurricanes,
tornadoes, or a very windy day!
Why aren't we scared of light winds while we stay inside during a hurricane or wind
storm? The velocity of those gangs of gas molecules have a dramatic impact on whether or
not we will be able to stay standing on our feet. In fact, in just a 20 mph gust you can feel
those gas molecules pushing you around.
Humans have been taking advantage of the energy in the wind for ages. Sailboats, ancient
windmills and their newer cousins the electrical wind turbines, have all captured the energy in
the wind with varying degrees of effectiveness. They all use a device such as a sail, blade or
fabric to "catch" the wind. Sailboats use wind energy to propel them through the
water. Windmills use this energy to turn a rod or shaft.
A simple equation for the Power in the Wind is described below. This equation describes a
the power found in a column of wind of a specific size moving at a particular velocity.
P = Power in the Wind (watts)
ρ = Density of the Air (kg/m3)
r = Radius of your swept area (m2)
V = Wind Velocity (m/s)
∏ = 3.14
r
From this formula you can see that
the size of your turbine and the
velocity of the wind are very strong
drivers when it comes to power
production. If we increase the velocity
of the wind or the area of our blades
we increase power output.
P = 1/2 ρ (∏ r2)V3
How much wind power is coming
from a regular house fan?
V = 5 m/s (meters/sec)
ρ = 1.0 kg/m3 (kilograms/cubic meter)
r = .2 meters
A = .125 m2 (Area of Circle = ∏r2)
Power in the Wind = ½ρAV3
Power
= (.5)(1.0)(.125)(5)3
The density of the air has some
= 7.85 Watts
impact as well. Cold air is more dense
than warm air so you can produce
There are 7.85 watts of wind power coming
more energy in colder climates (as
out typical house fan on high. Can our little
long as the air is not too thin!).
turbines capture all of this power? Do some
research on the BETZ LIMIT to find out.
How To Build a MINI Wind Farm
A wind farm is a collection of wind turbines in the same location. This may also be called a
“wind power plant,” because many wind turbines working together can produce a lot of electricity—just like coal or nuclear power plants. Wind turbines are often grouped together in
wind farms because this is the most economical way to create electricity from the wind. In
other words, wind farms give us the most power for our buck! Electricity from wind farms is
one of the most affordable sources of electricity today, and may soon be the cheapest form
as technology advances and fossil fuels become less abundant.
When you connect your various components together (wind turbines, load, meter, etc.), you
are making an electrical circuit. There are two ways of connecting components in a circuit:
series and parallel. A circuit wired in series has components connected end to end, like a
chain. The electrons must travel a single path through all of the various parts of the circuit.
A circuit wired in parallel provides a different path for current to travel through each of the
components. In parallel, each component has a separate loop.
Circuit Digrams: www.bbc.co.uk
Series circuit
Parallel circuit
Connecting Turbines:
If you are connecting the turbines in series, connect the wires of the turbines from positive
(RED wire) to negative (BLACK wire), making one continuous loop through the circuit.
If you are connecting the turbines in parallel, connect each positive wind turbine wire (RED)
individually to the red lead from the multimeter or load device. Connect each negative wind
turbine wire (BLACK) individually to the black lead from the multimeter or load device.
The wires you use to connect your mini wind farm to various loads act just like the high
voltage transmission lines that bring the electricity of real wind farms to our homes and
schools!
www.theage.com.au
The Power of Wind Farms
Recall the Power in the Wind equation:
P = 1/2 ρ (∏ r2)V3
P = Power in the Wind (watts)
ρ = Density of the Air (kg/m3)
r = Radius of your swept area (m2)
V = Wind Velocity (m/s)
∏ = 3.14
What are we changing in this equation when we add more wind turbines and create a wind farm?
The density of the air will not change, and adding more turbines will not change the wind velocity
either. But you definitely are changing the radius of your swept area (r).
Assuming your blades are all the same size, having three wind turbines as opposed to just one
will effectively triple your swept area! Of course, due to resistance and losses, we cannot expect
to get exactly 3 times the power. What are some of the causes of inefficiency and losses that
reduce your total power?
If you use a multimeter to record voltage and current as you add wind turbines to your wind
farm, you will find some interesting results.
When you have multiple turbines wired in series, the voltage will increase with each additional
turbine, but the current will stay the same!
If you wire the turbines in parallel, the current will increase with each additional turbine, but the
voltage will not change!
Power (Watts) =
I (current) x
V (voltage)
Three turbines in parallel will produce the same Power as the same three turbines wired in series.
If you put three turbines in series, you will basically triple the voltage with the same current.
Three turbines in parallel will effectively triple the current with the same voltage.
The Wind Park Effect:
If multiple wind turbines are placed too close to one another, the efficiency of the turbines will be reduced. Each
wind turbine extracts some energy from the wind, so directly downwind of a turbine winds will be slower and
more turbulent. For this reason, wind turbines in a wind
farm are typically placed 3-5 rotor diameters apart perpendicular to the prevailing wind and 5-10 rotor diameters apart parallel to the prevailing wind. Energy loss due
to the "Wind Park Effect" may be 2-5%.
What effect do you find when you move the turbines
around in your miniature wind farm? Try placing a few
turbines very close together, or right behind each other.
Do you notice a reduction in the efficiency of your wind
farm?
Wind Farm Layout to minimize "Wind
Park Effect" (www.windpower.org)
Wind Energy Facts
A wind turbine is the modern advancement of
the windmill. Instead of using the wind to lift
water or move heavy rocks to grind seeds wind
is used to turn an electrical generator to make
electricity.
The force of the wind on the blades causes
them to move. If the blades are all oriented in
the same direction they will start to spin, just
as the wind spins a pinwheel. The blades are
attached to a hub, which spins as the blades
turn. Most modern wind turbines have two or
three blades. This is due to the physics of
wind energy capture and a desire to reduce the
cost of the wind turbine. Blades are an ever
evolving aspect of wind turbines as the more
efficiently we can build and design them the
Photo Source: Vestas
more energy we can capture from the wind.
The blades and the hub together are called
the rotor. As the rotor turns, it spins a driveshaft which is connected to a generator inside
a housing at the top of the tower which is
called the nacelle. The spinning generator
produces electricity. Most utility sized wind
turbines have a gearbox between the spinning rotor and the generator; this is to help
the generator spin fast enough to make electricity for the grid. Generators on large grid
connected turbines spin at 1200 to 1800
revolutions per minute (RPM). On the
smaller residential turbines the rotor and the
generator spin at the same speed anywhere
from 0-500 RPM.
Wind Energy Resources & Links
Are you doing a science fair project on wind energy? These links will take you to some of
the most up to date and reliable information on the web.
KidWind Project
Wind With Miller
American Wind Energy Association
Wind Powering America
http://www.kidwind.org
http://www.windpower.org/en/kids/index.htm
http://www.awea.org
http://www.eere.energy.gov/windandhydro/
windpoweringamerica/
Check out www.kidwind.org for more great wind energy kits, free slide shows, experiment ideas, lesson plans, and activities, and links to other helpful resources.
Pressure (mb)
Temperature (C)
RH (%)
990.7
21
100
Density (g/m3)
1162
vapor pressure
dry air pressure
24.86008
965.8399
Kidwind Mini Wind Farm
www.theage.com.au
A wind farm is a collection of wind turbines in the same location. This may also be
called a “wind power plant,” because many wind turbines working together can
produce a lot of electricity—just like coal or nuclear power plants. Wind turbines are
often grouped together in wind farms because this is the most economical way to
create electricity from the wind. In other words, wind farms give us the most power
for our buck! Electricity from wind farms is one of the most affordable sources of
electricity today, and may soon be the cheapest form as technology advances and
fossil fuels become less abundant.
You can build your own wind farm works using KidWind PVC Wind Turbines or using a
few WindLab Jrs!
When you connect your various components together (wind turbines, load, meter,
etc.), you are making an electrical circuit. There are two ways of connecting
components in a circuit: series and parallel. A circuit wired in series has
components connected end to end, like a chain. The electrons must travel a single
path through all of the various parts of the circuit. A circuit wired in parallel provides
a different path for current to travel through each of the components. In parallel,
each component has a separate loop.
Circuit Digrams: www.bbc.co.uk
Series circuit
Parallel circuit
How to Connect Multiple Wind Turbines
When you connect multiple wind turbines together, you are making a mini wind farm!
You can choose to wire your turbines in series or in parallel. Before you build a wind
farm, you will need to hook up the wires correctly - and to do that you need to find
the polarity of each wire coming from your turbine.
Finding Polarity:
To correctly connect two or more turbines in a circuit, you will need to
find the polarity of the wires coming from your wind turbine. Finding
the polarity means figuring out which wire is positive (+) and which is
negative (-).
Connect your wind turbine to a multimeter. Make sure that the
multimeter leads are in the correct ports, as shown in the picture
(black to the left, red in the middle). Place the turbine in front of a
fan, and get a voltage reading. If your voltage is a positive number,
the wind turbine wire connected to the RED multimeter lead is positive
(+). If your voltage reading is negative, the wind turbine wire
connected to the RED multimeter lead is negative (-). Once you have
established which wire is positive and which is negative, it is a good
idea to mark them with some tape so you remember.
The polarity of the wires is determined by the direction your blades
are spinning. By changing the direction of spin you will change the polarity of your
wires.
Connecting Turbines:
Now it is time to choose whether you will
wire the turbines in series or in parallel.
If you are connecting the turbines in
series, connect the wires of the turbines
from positive to negative, making one
continuous loop through the circuit.
If you are connecting the turbines in
parallel, connect each positive wind
turbine wire individually to the red lead
from the multimeter. Connect each
negative wind turbine wire individually to the black lead from the multimeter.
The wires you use to connect your mini wind farm to various loads act just like the
high voltage transmission lines that bring the electricity of real wind farms to our
homes and schools!
Three WindLab Jr’s in a parallel circuit
In the parallel circuit,
all the negative wires
from the turbines go
separately to the
negative (black) side of
the meter and/or the
load. All of the positive
wires go separately to
the positive lead of the
meter or load.
+
—
+
—
+
—
You can see that the
current from each
turbine is able to travel
a separate path
through the circuit.
Each turbine in parallel
will increase the
current, but not
voltage.
Three WindLab Jr.’s connected in series
In a series circuit,
there is only one
pathway for the current
to travel. The leads are
connected negative to
positive to negative to
positive and so on.
With your meter
measuring voltage, you
will see that each
turbine in series will
increase the voltage. If
you measure current
through the circuit, you
will see it is unchanged.
—
+
—
—
+
+
For help on electricity and circuits, check out:
http://www.bbc.co.uk/schools/ks3bitesize/science/physics/electricity_1.shtml
The Power of Wind Farms
Recall the Power in the Wind equation:
P = 1/2 ρ (∏ r2)V3
P = Power in the Wind (watts)
ρ = Density of the Air (kg/m3)
r = Radius of your swept area (m2)
V = Wind Velocity (m/s)
∏ = 3.14
What are we changing in this equation when we add more wind turbines and create a wind farm?
The density of the air will not change, and adding more turbines will not change the wind velocity
either. But you definitely are changing the radius of your swept area (r).
Assuming your blades are all the same size, having three wind turbines as opposed to just one
will effectively triple your swept area! Of course, due to resistance and losses, we cannot expect
to get exactly 3 times the power. What are some of the causes of inefficiency and losses that
reduce your total power?
If you use a multimeter to record voltage and current as you add wind turbines to your wind
farm, you will find some interesting results.
When you have multiple turbines wired in series, the voltage will increase with each additional
turbine, but the current will stay the same!
If you wire the turbines in parallel, the current will increase with each additional turbine, but the
voltage will not change!
Power (Watts) =
I (current) x
V (voltage)
Three turbines in parallel will produce the same Power as the same three turbines wired in series.
If you put three turbines in series, you will basically triple the voltage with the same current.
Three turbines in parallel will effectively triple the current with the same voltage.
The Wind Park Effect:
If multiple wind turbines are placed too close to one another, the efficiency of the turbines will be reduced. Each
wind turbine extracts some energy from the wind, so directly downwind of a turbine winds will be slower and
more turbulent. For this reason, wind turbines in a wind
farm are typically placed 3-5 rotor diameters apart perpendicular to the prevailing wind and 5-10 rotor diameters apart parallel to the prevailing wind. Energy loss due
to the "Wind Park Effect" may be 2-5%.
What effect do you find when you move the turbines
around in your miniature wind farm? Try placing a few
turbines very close together, or right behind each other.
Do you notice a reduction in the efficiency of your wind
farm?
Wind Farm Layout to minimize "Wind
Park Effect" (www.windpower.org)