Talk:Darrieus wind turbine

message: The cant also makes the turbine self-starting from any position
Can you provide a reference to this, or explain it to me? I can't see how this helps. Since at zero rotational speed there is no "airspeed" over the blades, there can't be any lift, so it won't start moving. Any airspeed due to the wind alone will surely be cancelled by the drag on the rest of the structure - it's not enough to get it started. I may have missed something howevr; I'd be very interested to know about it if I have because I'm interested in building some turbines like this. Graham 05:08, 29 January 2006 (UTC)
replies: text: The way I think about the self-starting issue (though I could certainly be wrong) is as follows: The blades are airfoils, and if there is a wind across them, they will produce lift. However, if the rotor is stationary and the blade is pointed directly into the wind, the lift it generates (just like a plane wing) is directly away from the rotational axis, and doesn't do any good as far as rotating the assembly. When the rotor is turning, however, the actual wind combines with the APPARENT wind due to the rotation of the rotor, which results in a lift vector which points in a different direction...it points somewhat forward, which results in a net force continuing to drive the rotor. I don't think having more or fewer blades helps, it's the lack of the apparent wind that keeps the rotor from self-starting. However strong the wind is, the lift force generated by the blades will be directly away from the rotational axis and doesn't have any forward component. Middlenamefrank 00:59, 22 July 2007 (UTC)
thread_title: Self starting?

message: Hello, just about the thinking of ""Starting is achieved by the generator in motor operation" [1]
...
Can you provide a reference to this, or explain it to me?"
...Electric Motors are working on a very similar way as generators. 
A basic electo-motor has permanent magnets, so any (let it be a rotation-) part of the equipment which has a coil (current through that) can generate also magnetic field to pull itselves to the permanent magnet. This is the way the motors try to turn the axis. 
In addition; if you move the coil (this is a long wire rendered in an efficient way, looking like a life belt) near to the permanent magnet(s), there you will recognise some (potential), electic current, or electric power on the coil. So in this case your Motor works as a Generator.
I tryed to make it simple, as I can... SO, You can use a simple Electric Motor for the purpose of Generator, and in this case you can gain electric power from the motors (electrical) connectors.
Regards,
Csaba
(mailto:CsabaBalog@hotmail.com)
:Very simply, electric motors and electric generators are very similar devices, just run in reverse of each other. The motor provides motive power when electrically energized; the generator provides electricity when driven. Some designs work very poorly in the opposite mode, but some are designed to work at least acceptably well in both modes. Pumped-storage hydroelectricity discusses a reversible pump/generator application that shows decent efficiency on an enormous scale. Middlenamefrank 01:09, 22 July 2007 (UTC)
thread_title: Reversing the motor for rotor startup

message: I removed text which says that darreus turbine uses lower tip speed than normal HAWT, both use same wing-tip-ratio so there
is no difference in bird safety or noise. I have heard just some darreus or gyromills rotating and both where very noisy, I think that noise came from guy-wires.
I think that there should be reference that there is no any commercial Darreus any more.
:I don't think that's correct, I do believe the HAWT has a higher tip speed than the Darreus. The blades on a propeller-type turbine are arranged radially out from the axis, so the tips of the blades move much faster than points closer to the center, and considerably faster than the average blade speed. The Darreus' maximum blade speed is at the center for an 'egg beater' type, or uniform for the straight-blade type. Also, you should remember to sign your posts (four tildes does the trick) so we know who we're talking to. Middlenamefrank 00:44, 22 July 2007 (UTC)
thread_title: Lower tip speed

message: Where are they? Too Old 18:26, 25 April 2006 (UTC)
replies: text: They were removed because they were not tagged properly or had copyright issues. I've removed the text that references them for now - it's not too much of a loss for a general article, though if someone who knows more about this type of design wants to add it back (and sort out the image issues) then I wouldn't stand in their way. Graham 05:00, 26 April 2006 (UTC)
thread_title:  Figures 3 & 4 

message: I really think this figure is wrong. Indeed, the tangential velocityfor the blade in the back is in the inverse direction, so the aerodynamical force is also in a wrong direction. With the opposite tangential direction lift changes, but drag does not, thus, the total aerodynamical force only changes its vertical component which has to be pointing to the front of the apparatus. Carlos 00:22, 4 March 2008 (UTC)
thread_title:  Figure in explanation is partially wrong

message: I would rather not edit directly into the page, instead flesh out the idea here and then edit. 
Although Darrieus pantented the Darrieus type wind turbine in 1931 - filed 1925 (US pat 1,835,018) no actual invention came from the patent. It was not until the 1960s when two researchers at the National Research Council of Canada (NRC) "re-discovered" the Darrieus type wind turbine.  In an effort to create a realiable and maintainable power supply for developing regaions, Raj Rangi and Peter South, tested a model of vertical axis wind turbine (VAWT) in the National Research Council of Canada Aerodynamics laboratry.  It was only when applying for a patent in 1967 did they become aware of the Darrieus patent.  Modern Darrieus type VAWT systems derive from this re-discovery of technology.  —Preceding unsigned comment added by 142.46.198.195 (talk) 18:50, 15 April 2009 (UTC)
thread_title:  Canadian Contribution? 

message: On Dec. 5, 2009, is found: "just as efficient as the propeller".  That statement is in need of attention. We are not having "propeller" in a wind turbine; nothing is being propelled; autorotation is occurring. And where is there citation of efficiency ...efficient for what?   The return phase of the Darrieus blades is a costing sector of the motion.  Differently, a HAWT blade has no such return phase, but is working with lift in all angles of rotation. Something is needed here. Joefaust (talk) 08:15, 6 December 2009 (UTC)
thread_title:  Need reliable citation and proof of the fuzzy statement 

message: : Not Moved. A redirect has been created. Station1 (talk) 06:59, 29 September 2009 (UTC)
replies: text: Darrieus wind turbine → Darrieus WECS — —Preceding unsigned comment added by 91.182.179.23 (talk) 07:15, 21 September 2009 (UTC)

text: Oppose Darrieus wind turbine is a perfectly good title - Darrieus (name of inventor) wind turbine (what it is). I don't understand what is meant by "WECS". Perhapes it would be better to convert the requested destination title into a redirect instead. Mjroots (talk) 17:14, 22 September 2009 (UTC)
replies: text:  WECS means wind energy conversion system, the idea here is that the article could then be used to describe the Darrieus design, which can function to power wind turbines (electrical), aswell as simple mechanical devices.
*Oppose  We should not replace a descriptive name with a cryptic name.  Agree with creating a redirect at Darrieus WECS.  ~~ GB fan ~~ talk 13:02, 28 September 2009 (UTC)
thread_title: Move

message: made this little animation while trying to understand the aerodynamics https://www.youtube.com/watch?v=ne5Yv0uOre4
i have set it to CC, maybe you want me to make a special version for wikipedia.
I see a lot Darrieus wind turbines with ordinary "airplane" wings, even those that pitch its wing into the wind (http://www.srf.ch/player/tv/einstein/video/schweizer-erfindet-neuartiges-windrad?id=6109bc24-c926-474a-9fde-ac66c2a7071a). Okay, a little bent outwards would compensate the circular motion of the aerofoils. But this effect gets less the wider the diameter becomes. In my understanding, the aerofoil should even be bent inwards when in front of the wind.
I am also sceptical on the "Fig 4: Schematic of mass-stabilised pitch control system." (https://en.wikipedia.org/wiki/File:Massstab.windturbine.jpg). When the wind is used to pitch the wings, the wing will always be a "little to late" as the tilt becomes only a reaction to the wind. With that fast changing wind direction in the turbine, i am unsure if that will give some extra energy. Who  uploaded that Image ? Any prototype having proved that concept ?
--Verlierer (talk) 11:17, 3 December 2015 (UTC)
thread_title:  pitching aerofoils..