Abstract

Purpose/Hypothesis

Literature Review

Experimental Design

Materials/
Equipment

Test Station Construction

Procedure

Observations

Results

Statistical Analysis
Conclusions

Discussion
Sources of Error

Applications
Phase 2

Glossary of Terms

Acknowledgements
Bibliography

Home

Calculations

The data collected for each rotor variable was input into an Excel spreadsheet to calculate the mean, standard deviation and coefficient of variation of the ten measurements each of wind speed, weight and RPM. A shortened example of the spreadsheet is shown below in Table 2 to provide the formulas used to calculate the statistics.

Torque Calculation from Weight Measurements
Torque was calculated using the following formula:
Torque in Newton-Meters = Weight in Newtons x Radius of Axis
The radius of the axis = .003175 meters

Tip Speed Ratio Calculations
Additional calculations were done to calculate the Tip Speed Ratios of each rotor variable at low, medium and high fan speed.
Blade Tip Speed = RPM X Pi X Rotor Diameter / 60
Pi = 3.14
Tip Speed Ratio = Blade Tip Speed (m/s) /Wind Speed (m/s)
A shortened example of the Excel spreadsheet may be seen below to show the formulas used for the calculations.

Calculated Blade Tip Speed and Tip Speed Ratios at low, medium and high fan speed can be seen below.

Rotor Variable vs. Blade Tip Speed & Tip Speed Ratio at Low Speed

Rotor Variable vs. Blade Tip Speed & Tip Speed Ratio at Medium Speed

Rotor Variable vs. Blade Tip Speed & Tip Speed Ratio at High Speed

Mechanical Energy (Power) Calculations
Power in watts was calculated using the following formula:
Power in watts = Torque (N-M) x Blade Tip Speed

Power vs.Rotor Variable at Low, Medium & High Fan Speed

Results