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gotwind
Forum Admin
United Kingdom
762 Posts |
 Posted - 23/04/2008 : 20:26:10
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Hi guys.
My turbine tower is down at the moment, otherwise I would do this myself.
It would be interested to see how the 4 foot diameter pvc propeller would work as a down wind turbine?
As far as I can see it is just a case of removing the tail fin and removing the hub and reversing the blades.
Superwindy or similar it would be interesting to see if the blades area is enough to 'steer' the blades into the wind.
I am aware of the pro's and cons of downwind turbines, just be an interesting quick experiment.
http://www.windpower.org/en/tour/design/updown.htm
A typical down wind machine below, the Proven is another succesful version.
http://www.provenenergy.co.uk/windturbine_products.shtml
Ben.
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gholt
Starting Member
USA
47 Posts |
Posted - 24/04/2008 : 03:49:13
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The wind shadow can be reduced in a downwind turbine by using a symetrical (neutral) airfoil such as NACA 0012 as the motor mount. If tall and wide enough, this type mount can add vane effect to help keep the downwind unit in the wind. If more vane effect is needed, one might add a vane to the unit below the radius of the rotor blades.
G.
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MattM
New Member
USA
84 Posts |
Posted - 24/04/2008 : 06:32:30
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So what do you do in high winds?
Go Huskers! |
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gholt
Starting Member
USA
47 Posts |
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Capt Slog
Starting Member
United Kingdom
29 Posts |
Posted - 24/04/2008 : 08:57:24
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Ben,
That picture in your post......
is it the windmill of the Tellytubbies? |
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gotwind
Forum Admin
United Kingdom
762 Posts |
Posted - 24/04/2008 : 09:36:11
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Genuine unit, I found on google images - Chinese I think..
Does look a bit toy like agreed.
With the pvc blades, I would assume they would flatten out in higher winds and self furl to some degree, with a down wind type there is no chance of the blades striking the tower either.
Ben. |
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MattM
New Member
USA
84 Posts |
Posted - 24/04/2008 : 13:56:33
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gholt, I followed that link and did not notice any furling. I did try to find out about the idea 6-7 months back and don't recall ever reading about a downwind design furling. The general impression by people that played with it seemed negative overall.
Go Huskers! |
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gholt
Starting Member
USA
47 Posts |
Posted - 24/04/2008 : 23:48:52
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Here's the furling set up by E. Lenz:
(Ed or Ben, if you have any objections to the direct links to these photos I'll remove them)
G. |
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MattM
New Member
USA
84 Posts |
Posted - 25/04/2008 : 03:29:32
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Awww, it lifts. That should be a pretty simple way to do it. As long as the blades can support the weight of the assembly there shouldn't be a problem with implosion. I can see where you'd have to have a stop on each point so that the blades didn't hit the pole above or below. Shifting winds can play tricks with bulletproof ideas like that. :)
Go Huskers! |
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sacongo
Starting Member
USA
39 Posts |
Posted - 25/04/2008 : 04:24:32
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The picture Ben posted is of a skystream which seem to be a downwind turbine. Here a video of it in action.
http://tinyurl.com/6hh9bk |
Edited by - sacongo on 25/04/2008 04:29:48 |
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Nice little project for someone??
