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Air Bender
Senior Member

Joined: 25/01/2011
Location: Australia
Posts: 206

Posted: 01:50am 28 Oct 2011

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Hi all,
There have been a few posts on different Vawt ideas lately so I thought I will add my own. I dont know if I will ever get time to build something like this but it may work.

The rotors or rotor is built into a wing, and the wing pivots around on the pole to face the wind.
The idea is the wind will speed up over the curve of a wing and should spin the rotors faster than normal, and the rotor fins on the upwind leg will be in a wind shadow as they are set into the wing, reducing drag. If you run two rotors they could be geared together or run two seperate alternators which could be wired in paralel or series.
Any other ideas or improvments to this one would be welcome.

All the best Dean.

smithy
Regular Member

Joined: 30/01/2011
Location: Australia
Posts: 52

Posted: 11:12pm 28 Oct 2011

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That configuration is aften refered to as a "shrouded VAWT".

It would most likely be used with a drag style VAWT, so a low RPM high Torque configuration.

Regards Smithy

"The answer my friend is blowing in the wind, the answer is blowing in the wind" Bob Dylan

Greenbelt

Guru

Joined: 11/01/2009
Location: United States
Posts: 566

Posted: 05:16am 31 Oct 2011

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Hi All,

I have something to add to the who done what post.

I 've done more drawing than building or testing except for a small 2 foot dia. Model.
Made from plywood and 1/4" Mahogany wall panel
(1 x .75 foot buckets).
With a powered fan directed on it the power pulses were hi torque
At 90 degrees rotation It would not start up. this is why a stacked system
would be the way.

Edited by Greenbelt 2011-11-01

Time has proven that I am blind to the Obvious, some of the above may be True?

MacGyver

Guru

Joined: 12/05/2009
Location: United States
Posts: 1329

Posted: 11:40am 31 Oct 2011

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greenbelt

If you were to pull the scoops more towards the center of rotation, you'd find it would start of its own accord more of the time. Unfortunately, doing this diminishes the leverage and the power goes way down. It'll keep the crows out of the garden at least!

The only way anyone has ever been able to extract any power from a VAWT is by using a wing, which uses apparent motion to actually "fly" through the wind. This, along with leverage, can produce a measurable amount of power.

I'm on the verge of building another VAWT that uses a diffenrent principle. It uses a completely flat, lightweight blade emersed in a vortex of whirling air. It has lots of torque, self starts and runs quietly. I'll build it and post the build as soon as I'm done with the little axial-flux machine I'm working on presently.

. . . . . MacEdited by MacGyver 2011-11-01

Nothing difficult is ever easy!
Perhaps better stated in the words of Morgan Freeman,
"Where there is no struggle, there is no progress!"
Copeville, Texas

Greenbelt

Guru

Joined: 11/01/2009
Location: United States
Posts: 566

Posted: 06:38pm 31 Oct 2011

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Hi McGyver

I tried modifications to find a shape that worked best and that included shortening the scoop, this it what happened to my creation.
Notice when the scoop is 90D. to the wind there is a large hole straight through the
thing. the wind doesn't know there is something in its way.
It would turn 1/4 turn with a start assist and then stop as if the brake was activated

-------Cheers, Roe

Time has proven that I am blind to the Obvious, some of the above may be True?

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