name that sail

[revned]

Years ago, in popular science mag, I saw a new type of sail. It wasn't of sail cloth, nor even a panel. It looked more like a wind turbine, with three or four blades, top to mid, on a mast. I also saw one on a research vessel at the Ventura marina, in about 1990. I would really like to research the idea of rigging one to a canoe. Why? I don't really know, other than it would be different, and who knows, it might work. If anyone knows the name of this sail, please tell me, I just can't remember.

[dionysis]

Hi revned,

If you mean a proper wind turbine like the kind that generate electricity on hilltops, then you could be talking about Te Waka, designed and built by Jim Bates of Whangarei, New Zealand.

Cheers, dionysis.

[revned]

No, it's not that. It's a sail, not a gyro, or propeller, driven by an engine. And the blades, or veins, are attached at top of mast, and around mid mast, looking like a turban kind of streched out. The idea, I'm guessing of course, is to catch the wind from any direction. Myself, I couldn't see how it would work with the blades being narrow and all, but it was featured in Popular Science mag, mid to late 70's I believe. But I do appreciate the direction for learning something new and different.

Something like this?

http://www.wingsails.com/wingsail.html

[lockhughes]

...or something like this maybe?:


otherwise... maybe draw a pic and upload?

[revned]

Thanks a bunch for your replies, guys'. Both of the concepts posted are the same, but different, and the wing sail is more than likely the sail I'll build and use for my canoe. Though neither are the sail I was trying to find, just as well I suspect, because more research has gone towards the wing sail. Most likely a better and simpler design, and my guess is, simpler is better while sailing. So, thankyou all again, I will build my wing sail and start skipping the white caps in my canoe. And please, come on down to Laughlin, NV. and sail the Colorado river and Lake Mohave, with me. Plenty wind and water. God bless Rev. Ned

[jazz4kurt]

Didn't Jacques Cousteau have a boat mounted with that?

[lockhughes]

Originally Posted by jazz4kurt

Didn't Jacques Cousteau have a boat mounted with that?

Hiya jazz4kurt... Yer first post here I see... I haven't been alongside here myself in some blue moons, but anywayz, welcome aboard the good ship boatdesign.net <smile>

Wow. Yer posting to a thread from 2003???

OK, well, now you have me wondering how or if revned ever constructed their "sail" Yeoooo, REVNED???? Ya there?

Anywhoo, jazz4kurt, re Cousteau's boat? That'd be the Alcyone, I believe.

This site has some nice pics (near bottom of page), together with an explanation of the Magnus effect:
http://colaco.freeshell.org/downloads/downloads.htm

http://www.boatdesign.net/gallery/data/500/alcyone.jpg

[jazz4kurt]

This is the torque effect of a spinning cylinder. Why is this associated with the seemingly stationary cylinders on the Alcyone?

[lockhughes]

Originally Posted by jazz4kurt

This is the torque effect of a spinning cylinder. Why is this associated with the seemingly stationary cylinders on the Alcyone?

I said earlier:
This site has some nice pics (near bottom of page), together with an explanation of the Magnus effect:
http://colaco.freeshell.org/downloads/downloads.htm

(The Magnus effect characterizes the lift force exerted on a rotating cylinder in an uniform flow. The lift force is proportional to the fluid density, uniform flow velocity and the rotation speed of the cylinder. It is named after H.G. MAGNUS (1802-1870), a German physicist who investigated this effect in 1852. The rotor ship, designed by Anton FLETTNER (1885-1961) about 1924, used this principle. It was designed by mounting large vertical circular cylinders on the ship and then mechanically rotating the cylinders to provide circulation. More recently a similar system was developed for the new ship "Alcyone" of J.Y. COUSTEAU. The flow past a rotating cylinder may be achieved by the superposition of an uniform flow, a doublet at the origin and a vortex at the origin. The rotation of the cylinder induces a velocity acceleration on one side of the cylinder, associated with underpressure, and a fluid deceleration on the other side associated with an increase of pressure. The resulting pressure difference across the cylinder generates a lift force acting normal to the flow velocity. The Magnus effect it is responsible for the curve of a top-spin tennis ball or a driven golf ball, and it affects the trajectory of a spinning artillery shell and intercontinental missiles. On the Alcyone vessel, the rotating cylinder was replaced by some suction effect on parts of the cylinder. The resulting flow pattern is very close to that of the flow past a rotating cylinder, without the cumbersome apparatus.)

I'm *guessing* this is an explanation. Didn't get a second opinion. Sounds about right though...

Lock

[jazz4kurt]

The sails on the Alcyone don't seem to have any possibility of spinning...
What is the relationship?

[Guillermo]

Here how Alcyone's sails work:
http://bluegreenpictures.com/perl/Cy...ew;inum=125790

[jazz4kurt]

The quote from the skipper on that link says they don't.

[dimitarp]

Every wind turbine can work as sail

[messabout]

Recently, reading old copies of Wooden Boat, I came a cross an article that described with drawings and pictures, a boat with rotor blades on a mast. Looked like helicopter blades and they drove an underwater propeller. It worked after a fashion. It was most efficient dead to windward but did not go as fast as a conventional sail rig. It could make good to windward at about the same speed as the faster conventional boat. Thats because it could go straight into the wind, tacking not required. Not very efficient downwind. The mast could rotate and the gear box and all that stuff was rather complex. Probably heavy too.

I've been whacked a few times by an errant boom and survived. Not too enthused about getting whacked with a rotating blade.
I hope you are not serious about this thing on a canoe.