hey guys ! a new type of windmill (french site)

[titof]

Does the wind blow over your house ?
here's one who is not going to pay for electrons !

Have courage  !
Post your photo when finished !

[Evil Roy Slade]

All good ideas here people.

As has been pointed out, in order to use the wind energy on the 'UP' leg the blade must be
correctly positioned and oriented, which requires the 'blade flip'.

We have experimented with this and found the mechanical losses in controlling the blade outweigh
the additional power generated resulting in a degradation of overall power output. But if you guys come up with something clever I would love to hear about it.

At the moment we are investigating the possibility of CHANGING the shape of the blade instead of flipping it. There are a few ways to do this, all are in the melting pot. I am mentioning this here to sew a few seeds in the fertile brains out there!

ERS

[robbie47]

As has been pointed out, in order to use the wind energy on the 'UP' leg the blade must be
correctly positioned and oriented, which requires the 'blade flip'.

I assume you refer to my remark on the flipping of blade shape if shaped blades are used to gain the 'sailing' effect, so let me respond.

The simple solution I have in mind here is not using wood or steel but real sail material. This keeps the weight low and no additional control is needed.
Using sail kind of cloth has of course also some drawback. It's less robust on the long term, and it could make some additional noise ('flapping' of the sail for blades that are in the 'flipping over zone', so between say the 4 and 2 o'clock area)

[minesapint]

My latest design is a pure lift based design.
3 Symetrical foils each at 120 degrees.
A dc worm geared DC motor driven with PMW which averages at the overall sweep speed but speeds up or slows down in the cycle to provide a constant 20 degree angle of incident (optimum for my foil design) to the wind direction. This produces a thrust perpendicular to the wind.The thrust is one way for half the cycle and the other for the other half. I have some diags to explain this....
I have designed the electronics, sourced the motors, I have 3 one metre square blades made of strong polystrene  (in my garage). I need to get back out there and start welding it all together at some point but metal work is not really my strong point.
I was planning on putting it on a trailer so I could drive it to different windy locations, my house is quite sheltered. But this makes the metal work even more complex as it'll need to be easily assembled / disassembled.
The simulations I have done show that it will reach the efficiencies of a HAWT but will work at low speeds and high speeds (you simply reduce the attack angle and thus reduce the efficiency, stops the thing tearing itself apart).
Also with this design you can easily make a multipole motor on the base negating the need for a gearbox which keeps it quiet and efficient.
Interested if anyone wants to help out on this project, by trade I am an electronics / software engineer - need someone with good mechanical skills.

[robbie47]

Sorry, wrong action again. One can not delete mistaken posts here.