another idea

[cyclops]

The Sail and Gasoline companies killed them.

[yokebutt]

To understand this contraption going straight upwind from a traditional sailors perspective, first look at the propeller, it's rotating, ie. the blades are moving at right angles to the wind, then look at the boat itself, its moving into the wind.

Now, combine those two and look at the path a propeller blade takes, it's oblique to the wind! just like a regular sailboat! albeit in a corkscrew motion instead of a straight line.

Of course, it's not really that simple, but it's a good picture to start from.

Thoroughly confused yet?

Yokebutt.

[MattZ]

The law of conservation of energy always applies. There's a tiny exception in nuclear physics where a minute amount of energy can be "borrowed" for a near infinitesimal period of time.

The blades on the wind turbine have a very steep pitch, allowing the wind to pass through them, the creates rotational power, but also creates a force pushing the boat in the direction of the wind. By using a propellor with a fine pitch and/or steep gear reduction, it will be able to turn. Selecting the correct turbine and propellor pitches, as well as gear ratio is the key. As long as the propellor makes more thust than the turbine and hull creates wind drag, the boat will more forward.

[Chickadee]

Revelation II

They say downwind is more a problem than upwind. I think it must be somewhat slower than with normal sails?

I do remember an article in a sailing magazine, more than 20 years ago, with pictures of a 1-2 meter model sailing upwind.

[MattZ]

They should be just as capable of sailing downwind as upwind. The gearing between windmill and propellor would be different though.

[Chickadee]

Sorry, I have never sailed a windmill, that's just what they say on their website. "Unlike a normal sailing craft this vessel makes its' best time sailing straight into a headwind."

Downwind is great, but in light airs the apparent wind is more variable in direction, and with high wind and waves you'd better not leave the helm too long ! The windmill boat must react differently, same problems, but different effects ? Windmill performance must be affected by these quick changes, how much, I don't know.

But I still believe it must be a bit slower overall than the same boat with sails - except for headwind, obviously -because of the additional losses in gear and prop.

Maybe the primitive of the performance prediction curves (0-180°) could be the same in both cases ?

[Renneriffic]

I've had a riff on this idea for a while, based more on the ability of a rotating wing having the same lift capabilities of a fixed wing, based on the abilities of both a helicopter and a plane to be able to glide similiarly without engines. Last night I met a guy at the Antigua Boat Show who told me about a guy in RI that made one of these (with a propeller in the water powered by the windmill) and used to sail "directly upwind" as he put it. He may be mistaken, but I think the more important thing, which I hope to try, is whether a boat can propell itself with the windmill exclusively. Not directly upwind, but a reasonable sailing angle. I will be forwarding these and other links to him and try to find out who he was, and if there is any more info I can pass along. I have seen the wave boat that can go directly into the wind/waves, but that involves one very important factor not relevent to this machine...Gravity!

[masalai]

Yipster, I was just going through some old stuff which I thought may be interesting, It is but it appears the website of Peter Worsley's has been captured by "crap promotions" and the like. Advise him to get his ISP to run linux as a more secure system. I would love to see his stuff.

http://www.oceanblueone.com/rot.htm

[masalai]

Jeees has this degenerated into a crap shoot. If half the unbelievers went to NZ and saw the aforementioned cat they would become instant aliens and praise this superior being who could defy the laws of their own tiny brain = idjit. Think outside the box, get a life and look beyond your own nose.

Sorry Yipster, but some wankers could restrain/retrain themselves and make a model. Easy enough done, but that would spoil their self-righteous ignorant pontification.

[yipster]

your right, this were all interesting but now broken links, some popping crab up and it is a shame XP hasnt even virus protection
Peter Worsley has a wingsail site now i see, a while back he posted upwind turbine movies here but cant find them back quikly now
better contact Peter Worsley yourself as i share the linux ideology but my programs cant work with it

[masalai]

Thanks Yipster. Much appreciated. May save you some research ???

[yipster]

you may want to read Peter's post on the forum

[masalai]

I clicked on "post" but boatdesign could not find it, but in the name of Peter Worsley, only came up with your two citations in this thread????

[yipster]

sorry, "see all post by windmster" dont work in a link
Wingsail Test Videos now Uploaded
finds him, click public profile than see all post by windmaster
i'm sure he posted some more movies

[masalai]

Hell, it's 2:20in the morning. Good night all and thanks for a most interesting read.