Name: Midway Middle School, Rigby, ID
Wind Turbines and Graphing
Pitch, Number of Blades, Mass
Objectives
1. Understand experimental variables and controls
2. Understand blade pitch
3. Understand how to construct a line graph
4. Understand how to use a line graph to predict
Materials
1. Fan
2. Multimeter
3. Blade pitch demonstration unit
4. Graph paper
Procedure
1. Set up blade pitch demonstration unit
2. Set pitch to 00
3. Record results in table
4. Repeat for 50, 100, 150. 200, …
5. Graph results
6. Predict optimum pitch
7. Test to see if the prediction is correct
Results
Pitch
*Report template created by Mike Winston, Shelley School District*
(Two Blades)
Angle
Voltage
(degrees)
(v)
0
0
5
3.44
10
2.56
15
1.69
20
1.55
25
1.29
30
1.01
35
1.03
40
0.77
45
0.63
50
0.64
55
0.51
60
0.48
65
0.40
70
0.36
*Report template created by Mike Winston, Shelley School District*
Conclusion
1. What do you think the optimal pitch will be?
Our guess is that a pitch 450 is going to be optimal pitch.
2. What was the optimal pitch?
The optimal pitch was at 50
3. Were you correct? Explain why you might have been wrong.
No, we were not correct. Our team thought that a pitch of 450 was going to be the best
because is between 00 and 900 in which cases the turbine won’t spin.
Results
Number of Blades
(At 50)
No. of
Blades
0
2
3
4
6
12
Voltage
(v)
0
3.44
2.52
2.58
2.07
1.47
*Report template created by Mike Winston, Shelley School District*
Conclusions
We predicted that the more blades we have, the less voltage we get because of the weight.
Our predictions were correct as we can see in the previous table and graph.
Results
Mass
0
(Two Blades set at 5 . Mass is measured without the hub)
Pennies
per
blade
0
1
2
3
4
5
6
7
8
9
Mass
(g)
16
21
27
32
36
42
48
53
58
63
Voltage
(v)
3.42
3.50
3.46
3.38
3.26
3.20
3.10
3.02
2.90
2.66
*Report template created by Mike Winston, Shelley School District*
Conclusions
Mass was the last variable we tested, and we predicted that the more weight we put on the
blades, the less voltage we would get. We thought that we were going to have a similar table
and graph than the ones we got for the number of blades. However, we got a different result
and we were surprised, because as we increased the weight, the voltage did not decrease in
the same way it did when increasing the number of blades, rather, the voltage was almost
constant. We also were surprised when we got the highest voltage of the whole project when
added a penny on each of the two blades.
*Report template created by Mike Winston, Shelley School District*