ENGR305 windbelt: Difference between revisions

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Background

The windbelt, first designed by Shawn Frayne, is a device that converts wind into usable electricity by the principle of aeroelastic flutter. Unlike conventional wind turbines, windbelts are effective at producing electricity at low wind speeds. Regions that typically have lower average wind speeds are perfect for windbelt installations. However, windbelt design is relatively new and experimental. New materials and new designs must necessarily be tested to advance this potential source of clean energy.

Oppurtunity Definition

Though conventional windmills produce relatively little power at low wind speeds, windbelts can take advantage of the areas low average wind speeds. So far, three separate groups of Humboldt State University students have built windbelts, each time improving the windbelts design. This project, completed by Greg Pfotenhauer and Agustin Gonzalez serves to further improve upon the design of the windbelt and test new materials.

Literature Review

The following is a review of the literature of the available information relating to windbelts.

Windbelt Basics

Paragraph on the basics. The windbelt, invented by Shawn Frayne in 2004, is a device that converts wind power into electricity. The device is fairly simple, cosisting of a taut string or ribbon strung between two points. Wind blowing across the taut material produces the aeroelastic flutter effect, causing the ribbon to vibrate. This motion is translated into electricity by permanent magnets on the ribbon. The magnets move in and out of electromagnetic coils in accordance with the motion of the ribbon. This induces a current in the coil's wire. ^[1] A diagram of a typical windbelt is shown below.

WINDBELT.JPG

Unlike conventional wind turbines, which require expensive bearings and gears to be efficient, windbelts are relatively easy to construct at a low cost. This makes the windbelt much more feasible than conventional wind turbines for areas with low average wind speeds. ^[2]

The following makeup the basic components of a windbelt:

Frame Windbelts are exposed to the elements and are subject to UV radiation, temperature change, moisture, and variable wind speeds. Therefore, the frame must be durable. This means the frame and strong as possible.

Consideration should also be taken as to how the windbelt will stand or be mounted. High winds can create a lot of torque upon the windbelt's mount and can damage the windbelt or the structure it is attached to if the mount breaks.

Ribbon The ribbon must be lightweight and thin so it acts like an airfoil when wind blows across it. It must be fairly rigid, as too much elasticity will disrupt the vibration of the ribbon. The ribbon will be taut and subjected to potentially high wind speeds, so the material must have a high tensile strength. Finally, it must maintain its shape over time to be effective (objects that do not deform quickly over time are said to have low "creep.") This being said, there are relatively few materials (so far) that pose as promising materials for windbelt construction. The material used in Shawn Frayne's design is a mylar-coated taffeta. ^[3] Similar materials, such as kevlar, tape, or camera film can be used alternatively. Further testing of ribbon materials is necessary to improve the efficiency of windbelts.

Magnets Neodymium magnets seemed to be the most widely used and will be used in this windbelt. ^[4]

Coils The coils for windbelts can come from a variety of places. For instance, the coils from old hard drives can be used. ^[5] Coils can also be wound by hand, lessening the cost. ^[6]

References