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Dinges
Senior Member

Joined: 04/01/2008
Location: Albania
Posts: 510

Posted: 09:53am 22 Apr 2009

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[quote=Glenn]Lots of sun though, someone needs to invent a solar power windmill.[/quote]
Someone already did, Glenn:

http://en.wikipedia.org/wiki/Crookes_radiometer

Must say that your VAWT looks pretty nice, more pleasing to the eye than most contraptions I've seen yet. I agree with Gordon though, it doesn't look very stiff; maybe it'd help to add a few more struts diagonally to stiffen it?

Peter.
---------------
"if you can't fix it with a hammer, you've got an electrical problem."

Billy Bloggs
Newbie

Joined: 28/04/2009
Location: Australia
Posts: 2

Posted: 12:09pm 02 May 2009

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Hi Glenn,
Any further updates on the VAWT
Over 10 Days without wind - Whats your dietary secret?
You state that it will be to small to drive a F&P so have
you done the maths to calculate the theoretical max Watts?
I would but I'm having difficulty remembering how it all works.
It's amazing how your brain turns to mush as you age and change careers. (The Nintendo isn't really helping but at least now I'm good at Sudoku.)

Ian

Gizmo

Admin Group

Joined: 05/06/2004
Location: Australia
Posts: 5119

Posted: 03:58am 04 May 2009

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Well I was about to give up on the VAWT, the wind is just not consistant enough to do any testing. A couple of times I've spun it up by hand, and it keeps going for a few minutes, but as soon as the wind drops off it stops.

But today I walking out to see it spinning, started all by itself. It ran for about 30 minutes, quite fast at times. So it does self start, and seams to go ok. I took some video and will post on youtube later.

Think I'll take it down for now and test it again when I get to a better location ( windy place ). Its got potential.

Glenn

The best time to plant a tree was twenty years ago, the second best time is right now.
JAQ

Gizmo

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Joined: 05/06/2004
Location: Australia
Posts: 5119

Posted: 08:02am 04 May 2009

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Here's a video of the VAWT running. No load, just free wheeling.

http://www.youtube.com/watch?v=yjgRZCuR4R8

Glenn

The best time to plant a tree was twenty years ago, the second best time is right now.
JAQ

Jarbar
Senior Member

Joined: 03/02/2008
Location: Australia
Posts: 225

Posted: 12:07pm 04 May 2009

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Bloody fantastic.

Anthony

"Creativity is detirmined by the way you hold your tounge".My Father
"Your generation will have to correct the problems made by mine".My Grandfather.

vawtman

Senior Member

Joined: 14/09/2006
Location: United States
Posts: 146

Posted: 10:41pm 04 May 2009

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Glen you had me worried for a momment there(few days).

Now imagine the power you could create with three FULL blades.Startup would even be better but the support structure would need beefing

I would run the supports from the center for the big guy if you build it.

Those blades are great for giro's.Mine are a bit thicker for more lift but those will work great also.

People think a skinny blade will cut through the upwind better on these but i disagree if the tsr is over 1 it's all lift all the way around.

Nice work and i think you have a new and better marketing for the blades

Are you a member of Windgen Vawts?Otherwise i could link to your endeavors.

Solar Junkie
Newbie

Joined: 03/05/2009
Location: United States
Posts: 5

Posted: 05:36am 05 May 2009

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Gizmo,

Have you or others tried setting these same blades at an angle to form a helix? i.e a 60 degree slant? Looks like it helps iron out some of the cons of the Darrieus/Giromill type VAWTs....???

Here's a computer mock-up. It has some pinching at the top and bottom like the eggbeater Darius turbines. I'm guessing the pinching is not 100% necessary to keep things more simple.

Wikipedia text says:
The turbine consists of three vertical airfoil blades, each having a helical twist of 60 degrees. This feature spreads the torque evenly over the entire revolution, thus preventing the destructive pulsations of the straight-bladed giromill (Darrieus turbine). The wind pushes each blade around on both the windward and leeward sides of the turbine.

Wikipedia text also says about a third of the way down on the screen on a different link:
Helical blades
The blades of a Darrieus turbine can be canted.... The skewed leading edges reduce resistance to rotation; by providing a second turbine above the first, with oppositely directed helices, the axial wind-forces cancel, thereby minimizing wear on the shaft bearings. Read full text here

Cheers,
Solar Junkie

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