Abstract

Purpose/Hypothesis

Literature Review

Experimental Design

Materials/
Equipment

Test Station Construction

Procedure

Observations

Calculations

Statistical Analysis
Conclusions

Discussion
Sources of Error

Applications
Phase 2

Glossary of Terms

Acknowledgements
Bibliography

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Results

The following is a brief summary of the results obtained. The chart below, shows the rotor variables that produced the highest torque, tip speed ratios and mechanical energy.

Rotors Producing the Highest Results for Torque, Tip Speed Ratio and Power

1. A single 28 cm rotor had a higher torque reading than a single 20 cm rotor at all three fan speeds. The difference was most noticeable at low speed where the 20 cm rotor had a torque of 0.0003905 N-M and the 28 cm rotor had a torque of 0.0017590 N-M.

2. Multiple rotors, either 2 - 28 cm or 1 - 20 cm and 1 - 28 cm always produced more torque than single rotors.

3. Torque was dependent on the rotor sizes, placement and blade position.

4. Torque increased as fan speed increased.

5. At low speed, the highest torque of 0.0028131 N-M resulted from 2-28 cm rotors, offset and 5 cm apart closely followed the same rotor orientation 3.5 cm apart with a torque of .0028004 N-M.

6. At medium and high speed, the highest torque (0.0039307 and 0.0050864 N-M) resulted from the 2-28 cm, offset, 3.5 cm apart rotors.

7. Overall, two 28 cm rotors, placed 3.5 cm apart with the blades offset produced the most torque.

8. Tip speed ratio at low fan speed was the lowest at 1.03 for a single 20 cm rotor and the highest at 2.59 for 1 - 28 cm rotor placed in front of a 20 cm rotor with the blades offset and 5 cm apart.

9. Tip speed ratio at medium fan speed was the lowest at 1.17 for the single 20 cm rotor and the highest at 2.54 for one 28 cm rotor placed in front of a 20 cm rotor, in line and 5 cm apart. A ratio of 2.52 was obtained for 2 - 28 cm rotors, offset and 3.5 cm apart.

10. Tip speed ratio at high fan speed was the lowest at 1.77 for the single 20 cm rotor and highest at 2.54 for the 2 - 28 cm rotors, offset and 3.5 cm apart.

11. Overall, two 28 cm rotors, placed 3.5 cm apart with the blades offset produced the highest tip speed ratio.

12. Mechanical energy produced at low fan speed was the lowest at 0.00175 for the single 20 cm rotor and highest at 0.03212 for one 28 cm rotor placed in front of a 20 cm rotor, in line and 5 cm apart closely followed by 0.03122 for the the 2-28 cm, offset, 3.5 cm apart rotors.

13. Mechanical energy at medium and high fan speeds was the lowest at .0065 and 0.0198 watts for the single 20 cm rotor and highest for the 2-28 cm, offset, 3.5 cm apart rotors at 0.0504 and 0.0735.

14. Overall, two 28 cm rotors, placed 3.5 cm apart with the blades offset produced the highest mechanical energy.

Graphed Results

Statistical Analysis/Conclusions