Vertical-Axis Wind Turbine

Kang Zheng

Aaron Peterson

Mohd Ramjis

Presentation Outline

Project Objective Background/Design Description Structural Analysis Fabrication Process Future Work Conclusion Questions

Project Objective

To design, build, and test composite airfoil blades for a wind turbine.

Background

A wind turbine is a rotating machine which converts kinetic energy in wind to electrical energy.

The use of wind turbine is important as it is the alternative to other main energy generators.

There are two major types of wind turbine determined based on the axis in which the turbine rotates. Horizontal Axis Wind Turbine (HAWT) Vertical Axis Wind Turbine (VAWT)

Vertical Axis Wind Turbine The main rotor shaft arranged

vertically Consists of three vertical airfoil

blades made of composite with each blade has a helical twist of 120 degrees

Blades mounted on aluminum flat plate

Design Description

Design Description

Why we chose this design? Tolerates higher wind speed Airfoil constantly in the direction of wind; reduce

noise and cyclic loading Higher airfoil pitch angle (improves aerodynamics,

decreases drag) Be located nearer to ground

The aluminum plate were designed in a circular fashion with arcs cut out (120 deg) to reduce weight while maintaining stability

Analysis performed on the aluminum plate by applying centrifugal force on the axis of rotation

Blades were designed for a twisted angle of 120 degrees

Simplified air pressure as pressure force on inner surface of the blade

Structural Analysis

Structural Analysis

Displacement1200 rpm 100 psi stress0.355’’ disp.

Structural Analysis

Displacement300 rpm 2.231e-6’’ disp. 17.38

psi stress

Scale Model Graphite/Epoxy composite with a foam core

blade Length: 35 in. Height of capture area: 27.5 in. 3 in. chord foam core

1/16” Aluminum sheets 24 in. diameter circle

Shaft 60 in. long, 1 in. diameter Aluminum shaft

Support structure 4x4 in. wood cross sections

2 1 10 / 45 / 90s

Fabrication ProcessWe started by cutting out small templates of the airfoil out of wood

Using these, we cut out foam cores of the airfoils for us to wrap the fibers around.

After each ply was laid, and epoxy was applied, we wrapped the mold with release film and added the vacuum tube.

Fabrication Process After the composites cured, we took the plastic off to make sure

that each blade cured correctly.

We trimmed the excess fibers and epoxy off of the blade, and then sanded it to make the airfoil create more drag.

Fabrication Process The bolts were fixed into the ends of the blades.

After the blades were completed, we constructed the aluminum plates for the top and bottom supports

Final Product

Results

What did we want? Rotational speed vs. wind speed Drag on the assembly

Why were we unable? Time constraints Limited access to AABL wind tunnel Lack of funding Tool limitations

Future Work

Future work: Add an alternator, voltmeter, pulley, and v-belt for

power generation calculation Add electrical system for the wind turbine Wind tunnel testing Optimize:

Weight Airfoil shape Angle of attack

Conclusion

Wind turbines are going to be in high demand as the switch to renewable energy is in progress

The blades made out of composite materials have greatly reduced the weight of the entire assembly

The composite blades also allow the structure of the support be manufactured out of lighter, and more cost effective materials

References

Special thanks to: Nathan Knop (T.A) Tom Elloitt (Technician) Bill Rickard (Technician) Vinay Dayal (Project advisor)

Questions