Abstract

Literature Review

Experimental Design

Materials/
Equipment

Test Station Construction

Procedure

Observations

Calculations

Results

Statistical Analysis
Conclusions

Discussion
Sources of Error

Applications
Phase 2

Glossary of Terms

Acknowledgements
Bibliography

Home

Purpose

The purpose of this project was to determine if multiple rotors will increase the torque of a horizontal axis windmill.

Torque is the force created by a rotating shaft and is measured in Newton-Meters. Since mechanical power (watts) is the product of torque and rotational speed, revolutions per minute (RPM) will also be measured.

I decided to do a project on renewable energy sources because other forms of electricity (nuclear, fossil fuel) are becoming increasingly expensive and damaging the environment. I chose to focus on wind energy because it is gaining in popularity and there is a wind farm project proposed near the area where I live.

While there have been many experiments and research done on windmill design, it seems that no one has tested multiple rotors driving a single shaft. I knew that turbine engines use multiple fans to increase airflow, and wondered if the same approach could work on a windmill. I also questioned whether the air passing through the blades of a single rotor could be captured and utilized by a second rotor.

This research could impact on the construction of wind turbines. Increased torque may permit increased turbine sizeand produce more electricity than that of a single rotor wind turbine.The use of multiple rotors to increase torque could result in lower construction costs because rotor blades would be smaller, fewer support towers would be required and the overall efficiency of wind turbines would increase.

Engineering Objectives

My engineering objectives were to design and build a multiple rotor, horizontal shaft, laboratory scale windmill. The scale model was used to determine the effect of different rotor attributes (size, distance apart and orientation of the blades) on the resulting torque and mechanical power output. The rotor arrangement that produced the most torque and mechanical power was identified.

Hypothesis

If a three-blade rotor on a horizontal axis windmill produces a given amount of torque and mechanical power, then adding another three-blade rotor will increase the amount of torque and mechanical power produced.

I predict that the distance between the rotors will affect the amount of torque and mechanical power produced and that there is an optimal distance.

I predict that the orientation of the rotors (i.e. blades off set or in line) will affect the amount of torque and mechanical power produced.

I predict that the size of the rotors will affect the amount of torque and mechanical power produced.

Literature Review