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Forum Index : Windmills : H-Darrieus

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MakeeK

Newbie

Joined: 16/11/2009
Location: Finland
Posts: 6
Posted: 06:14pm 15 Nov 2009
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Hello all,

I have planned to build VAWT like H-Darrieus.

I have few questions to make:

1. Airfoil shape? Usually those are NACA0015 or NACA0018? But this document tells that better would be S2027. Anything to comment? Airfoil

2. See this pic http://www.saunalahti.fi/markusco/roina/h-darrieus-lapa.jpg
What could be A and B dimensions if S2027 used? I planned to build about 6m long blades.
Is blade even right way assembled in the pic?

When blade is 6m long, diameter should be about 3,9m. Height/Diameter ratio could be 1,54 which has been proved to be good ratio. H/D-ratio

Any ideas or sugestions?

Edited by MakeeK 2009-11-17
 
SparWeb

Senior Member

Joined: 17/04/2008
Location: Canada
Posts: 196
Posted: 05:03pm 18 Nov 2009
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Airfoil: Doesn't matter. Ed Lenz uses a tear-drop shape, others use flate plates of aluminum, others use airfoils. It always makes the rotor turn.

The airfoil only "optimizes" the design. There are lots of other hurdles to jump over before getting to that stage of refinement in a VAWT.

Wider spaced blades make the machine want to turn slower, and it may also make it less likely to start turning.
Steven T. Fahey
 
MakeeK

Newbie

Joined: 16/11/2009
Location: Finland
Posts: 6
Posted: 08:40am 22 Nov 2009
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Where should be blade pivot? I build prototype of 2 bladed H-rotor and it didn't work at all until I moved pivot much more towards to the leading edge. But which place is optimal?

In the other hand look at this:
http://www.youtube.com/watch?v=CZ1KN0fKqyA&feature=related

There's blade pivot middle of the blade. So is pivot place even important?Edited by MakeeK 2009-11-23
 
vawtman

Senior Member

Joined: 14/09/2006
Location: United States
Posts: 146
Posted: 11:33pm 22 Nov 2009
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Why would you want to go through the complexity of pivoting the thing and not build proper blades for the rotation?
 
MakeeK

Newbie

Joined: 16/11/2009
Location: Finland
Posts: 6
Posted: 07:41am 23 Nov 2009
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Because I'm building small scale test version to try various blades and AOA's.
 
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