Wind Power C

[Frogger4907]

Are you guys using large blades (surface area - wise)? We've been using relatively smaller, longer blades, but we haven't tried 4 yet. I guess the situation calls for more blades than last year, due to the load.

Depending on your design, you have to find out how many blades is best. Having weight helps your momentum but too much will hurt you.

[jayadh]

so we actually did awesome on the biulding part but on the test nothing in the binder was on the test! States is in less than a month, help! equations? websites? SOS

[Celeste]

so we actually did awesome on the biulding part but on the test nothing in the binder was on the test! States is in less than a month, help! equations? websites? SOS

Get the wikipedia articles on all the different alternative energy types. (Wind, solar, OTEC, etc.) and print off the scioly wiki page, it's pretty good.

[c0gentf0rce]

I can't really say this without sounding arrogent(arrogant?), but for the last two years with only one exception, I've gone undeafeted at every competition I have gone to. It could just be that people in WA (no offense) are just bad at designing wind turbines, but last year me and my build team literally stumbled on to a design that has yet to be beaten, and its winning by a superwide margin. And all our attempts to rebuild and modify this particular blade have ended with it being worse than when it started. My question is, is anyone else experiencing this, or is our blade design totally unique? Also does anyone know of a superlight plastic I could replicate the design with, 'cause I'm thinking that plexiglass isn't exactly the best material we could be using.

Plexi is a very good material to use if you know how to use it. (and no I'm keeping that stuff a secret ) but what kind of numbers are you putting up against how much resistance?

I fully respect your secret keeping sir. with no resistance we've pulled a combined total of around 2.5V at compitition, we usually test at a higher load than compitition (to make sure it will turn), of about 10 ohms, and with optimal placement and if the stars are aligned correctly, we've seen it do around 600mv on high with an average of about 550-580mv.And it would be my desing I would be replicating, not yours. It also makes a lovely noise that soothes the soul.

PS. Feel free to mock me for my spellings, I is a physics person and I speak American, not english

Is that (2.5 V) the combined average voltage of high and low speeds speeds?

[kjhsscioly]

I just finished a three blade model - the least I have done so far. But from what some of the test questions talked about, it seems like a good idea. This time, I documented the entire process . Pics soon (maybe)

[fleet130]

Note: More resistance allows less current to flow in the circuit so the load is less. A lower resistance lets more current flow, so it places a higher load on the generator. To place the highest possible load (without adding an opposing EMF) on the generator (CD motor), connect the two wires coming out of it together.

An interesting experiment might be to use different resistor values and graph the power output (P=E^2/R) of your turbine as compared to the load resistance.

[illusionist]

So are you saying that 6.8 ohms of resistance allows the motor to spin easier than 5 ohms of resistance? Sorry, I have very little electrical experience other than soldering.

[fleet130]

So are you saying that 6.8 ohms of resistance allows the motor to spin easier than 5 ohms of resistance?

Yes. That's generally correct! The load is the power generated (P=IE or P = I^2R), not the resistance.

It should be fairly easy to demonstrate if you have access to an optically coupled tachometer. Set up your turbine with the motor leads unconnected (infinite resistance). Measure the speed reached by the turbine. Without changing the setup, connect the motor leads to each other (a dead short or 0 Ohms resistance). Measure the speed of the turbine again. There should be a measurable reduction in turbine speed.

Edit:I forgot to mention. An often-used technique to stop wind turbines from from turning is to short their output leads together, increasing the torque required beyond what is available.

[illusionist]

Has anyone tried asking a local wind power company for assistance in blade design? We have some companies somewhat close by, so I was wondering if it was worth it to ask if anyone there could provide assistance.

[kjhsscioly]

This seems a strange question, but does it matter if your blade assembly spins clockwise or counterclockwise? this is just a hunch, but the first one I built works the best by far, and it is the only counterclockwise one.