Compare Windmill Blade Angle Science Fair Projects

PROCEDURES

Build the Windmill Tower
1. Cut a 42cm x 42cm square out of pegboard for the base of the wind turbine tower and set aside.
2. Cut each of the two bass wood rods in half to form four smaller rods and also set aside.
3. Cut four 5cm x 30.5cm pieces out from the 1/16 inch x 4 inch x 24 inch bass wood board. Set aside.
4. Using Insta-Cure glue, glue the four 5cm x 30.5cm bass wood pieces to the four bass wood rods so that the four rods are the corners and the rectangles form the walls. This will be the tower that the DC motor rests on. The tower should be 30.5cm tall, 5cm wide and 5cm deep.
5. Put some of the Insta-Cure glue around the bottom edge of the tower and glue it in the center of the 42cm x 42cm base.
6. Cut a 5cm x 5cm square out of 1/8 inch x 3 inch x 24 inch basswood.
7. Use the Insta-Cure glue to glue the DC motor onto the edge of the 5cm x 5cm square so that the shaft goes over the edge of the tower.
8. Put glue around the top edge of the tower and glue the square with the motor attached to it to the top of the tower.

Blade Angle
9. In three of the craft circles drill a small hole in the center so that the shaft of the motor will fit tightly through it.
10. Cut five, 2cm long pieces from the 5/16 inch x 5/16 inch x 36 inch balsa wood rods.
11. Cut two of the 2cm long pieces in half horizontally, lengthwise to form four right triangles that have a 45° slope. Only three of the four will be used.
12. Cut the other three 2cm long pieces slightly off from diagonal so that one part forms 60° slopes and the other part forms a 30° slope.
13. Glue three of the 45° triangles onto one of the circles from step 9. Glue them flush to the edge of the circle so that one of the narrow ends of the triangles are facing the center and the 45° slopes are all facing in a counter clockwise direction.
14. Repeat step 15 with the 60° and 30° slopes and the other two circles from step 9.
15. Out of the two 2 1/32 inch x 3 inch x 36 inch balsa wood boards cut out nine 3.8 cm x 15 cm blades with the Exacto knife.
16. Glue the back 2 cm of the bottom left corner of the three blades onto the three 45° slopes so that the blades are protruding outward from the center.
17. Repeat step 18 with the other six blades and the 30° and 60° slopes.
18. Connect the digital multi-meter to the DC motor with the two alligator clips.
19. Take the blade circle with the 45° slopes and press it onto the front of the motor shaft.
20. With the pen or marker mark the motor shaft and the blade circle so that you can tell if the circle slips during the experiment.
21. Position the electric fan 42cm away from the end of the wind turbine’s base. Make sure that the multi-meter is ready and that a timer is set for thirty seconds.
22. Start the timer and turn on the electric fan. When thirty seconds has passed press the data hold button on the multimeter and record data.
23. Repeat steps 19-22 for the 30° and 60° slopes and record data.
24. Repeat steps 19-24 two more times so there are three trials for each blade circle.

Blade Length
30.Repeat step 9 with the remaining two circles.
31.Make six more blade angles at 30, 60, or 90 degrees depending on which did the best during the blade angle tests.
32.Repeat step 13 to glue the six angled slopes to the last two circles.
33.Cut three 3.8 cm x 12 cm pieces and three 3.8 cm x 18 cm pieces from the two 2 1/32 inch x 3 inch x 36 inch balsa wood boards.
34. Glue the back 2 cm of the bottom left corner of the three 3.8 cm x 12 cm blades onto the three slopes on one of the two circles from step 30 so that the blades are protruding outward from the center.
35. Glue the back 2 cm of the bottom left corner of the three 3.8 cm x 18 cm blades onto the three slopes on the other circle from step 30 so that the blades are protruding outward from the center.
36.Repeat steps 19-24 with the blade circles made in steps 30-35 and record data.

RESULTS

The original purpose of this experiment was to determine how the length and angle that a wind turbine blade is mounted would affect the amount of electricity produced.

The results of the experiment were that the wind turbine with blades mounted at a 30 degree angle did the best, producing 45.4 milli-volts of electricity on average. As the size of the angle increased the amount of electricity being produced decreased. The wind turbine with blades at 45 degree angles produced 33.3 milli-volts of electricity on average and the wind turbine with blades at 60 degree angles produced 19.63 milli-volts of electricity on average. The wind turbine with blades that were 12cm long did the best, producing 57 milli-volts of electricity on average. The wind turbine with the blades that were 15cm long produced 33.3 mill-volts on average and the wind turbine with blades that were 18cm long produced 34.5 milli-volts of electricity on average.

CONCLUSION

My first hypothesis was that the wind turbine with the blades mounted at a forty-five degree angle would produce the most electricity.

The results indicate that my first hypothesis should be rejected because the blades that were mounted at a 30° angle produced about 25 more milli-volts of electricity than the blades mounted at a 45 degree angle.

My second hypothesis was that the wind turbine with the longer blades would produce the most electricity.

The results indicate that my second hypothesis should also be rejected because the blades that were 12cm long (the shortest tested) produced about 23 more milli-volts of electricity than the blades that were 18cm long (the longest tested).

Because of the results of this experiment, I wonder if the shape and material that the blades are made out of and the number of blades would affect the amount of milli-volts produced.

If I were to conduct this project again I would have tested all of the sizes of blades with all of the different angles instead of just testing each size with the angle that did the best. I would have also tested some other angles and sizes and I would have had more trials. 3rd party contributor