We should try this

[zvizdic]

http://www.youtube.com/watch?v=ifF-MOuzM_s&NR=1

[scoraigwind]

That ducted thing is just a gimmick, and although huge sums of money have been thrown at it in the past it has not worked out for the investors.

[wdyasq]

I wonder how much area the 'rim' adds to the area of the small turbine. I did NOT see that addressed in the video.

'Under Theory' - a ducted wheel captures tip vorticies.

Ron

[finnsawyer]

     That flair in the back of the mill is designed to increase the speed of the air flow and hence reduce the pressure behind it.  That should give more power, but now you have in effect increased the capture area.  That should be taken into account.  Other effects also come into play.  The tip vortices are eliminated as, Ron mentioned, helping efficiency.  But another effect, probably most pronounced in small mills, that would be eliminated would be radial flow out of the mill caused by the pressure difference between the air flowing through the mill and the air flowing around it.  That flow would be forced to zero.  More air would flow through the mill causing operation to move higher on the efficiency curve.  If you're wondering what curve I'm talking about, you will find it in my diary titled "The Betz Limit - Again".
     So, should you try putting a duct around your mill?  Sure, what would it hurt?  It's not hard to laminate wood and fasten it to the blades.  If you need more support add some round struts.  Keep it simple.  A simple band.  You need not extend it in front of the blades.  Have fun!
   

[Lloyd]

Hi BobG.

Hello All,

My first post...but I know B..G...now that I have my cup of coffee.

Back to topic, I know nothing of the wind.

But what I do know is the world revolves around balance.

I have been reading about wind(the engine), mostly here.

What I have read about the engine(=screws) noone ever talks about the balance.

Balance is much like a ships propeller, and even a ships hull.

Now for the good screw,  like a ships hull, a screw in balance has no power, it has to overcome that balance to make forward movement.

Efficiency is where the thrust is greater leaving, than entering the screw(but reverse for wind).

In the case of wind, a vacuum leaving the screw, would upset the balance.

vertical or horizontal!

Lloyd

[electrondady1]

this sort of thing has been proposed before.
to me it all comes down to use of materials.
so the ring  increases power output,
 but the volume of materials used in the ring and the support structure could be used to form a second windmill.
doubling the total power output with out stress.

what's really required is a bullet proof low maintenance mechanism that can take anything the ocean can throw at it including being completely submerged.

perhaps the hexagon platforms could be used to create fish pens.
municipalities are going broke hauling away plastic waste to landfills.
how about recycling that and forming floating support structures.

it  seems every two weeks there is some new futuristic proposal put out
that will save us.
they all require study and development and will take a lot of money and time to come into use .
but in the meantime we have to keep burning that fossil fuel.

just an opinion






 

[fabricator]

I don't think I've ever seen it used on a down winder before.