Scioly.org

i tried building one like that 2 years ago with paper, but it didn't work at all. i didn't put much effort into it though, so my results are probably not that reliable.

Just a few questions regarding surface area of the blades - would a higher surface capture more air and thus produce more voltage? Keeping mass constant of course.

I think that increasing surface area would probably only work to a certain extent. Up to a point, it would help it get more air, but if it gets too big it wouldn't work as well. Also, the ideal size would probably vary depending on the pitch of your blades.

Hmm, im confused as to what pitch is. Is it the curvature of the blades or what? And also, what kinds of scores do you guys predict will medal at state - assuming everyone scores about the same test score, it's not really that hard to study for.

lllazar wrote:Hmm, im confused as to what pitch is. Is it the curvature of the blades or what? And also, what kinds of scores do you guys predict will medal at state - assuming everyone scores about the same test score, it's not really that hard to study for.

http://en.wikipedia.org/wiki/Blade_pitch
As far as I understand it, it's the angle between the direction of airflow and the plane of the blade.

lllazar wrote:Hmm, im confused as to what pitch is. Is it the curvature of the blades or what? And also, what kinds of scores do you guys predict will medal at state - assuming everyone scores about the same test score, it's not really that hard to study for.

Scores should be similar to states last year in physics lab/physical science lab. They may be a little more. It really depends on the fan and motor it is on.

Celeste wrote:I think that increasing surface area would probably only work to a certain extent. Up to a point, it would help it get more air, but if it gets too big it wouldn't work as well. Also, the ideal size would probably vary depending on the pitch of your blades.

eventually the blades will not start spinning and gain enough momentum before the minute is up...

yogi94 wrote:Has anyone tried a traditional wind turbine design like this?

http://apps.carleton.edu/reason_package ... 1155925043

This is just a theory, but I don't think this will be very effective. The reason that modern wind turbines are built that way is because they are designed to have a minimal environmental impact. Bird activists and the like have issues with the heavier windmills, as birds tend to fly into them, so the moder ones are designed this way, and are effective mainly because there are so many of them set up together. When power was needed out of a single windmill, as we need now, they looked more like this:

When you see these, they usually stand alone, in contrast to the "modern" type, which are usually only seen in large fields of similar windmills, usually able to turn in the optimal direction.

The windmill pictured above is optimized for high torque, low rpm. Generators are very inefficient (they generate very little power) at these slow speeds. For optimum power generation, they must turn at much higher speeds. At the higher speeds, the large surface area of the blades of the windmill type design create huge amounts of drag, making this design inappropriate for a wind turbine. That is why wind turbines have fewer blades (usually 2 or 3) that are more slender. As usual, this is only part of the story. A search of the internet should produce several websites that explain the theory of wind turbine vs windmill design.

Would 3/32 be sturdy enough to not flop around? Also, what is the equation for power that will be used....i know it's Fd/t but we just learned this in physics yesterday and i don't know how to derive a formula for electrical power generated.