'Sailing'?? Directly to Windward

[brian eiland]

I couldn't put this subject thread under 'sailing' as its not really sailing in the true sense of the word. But it is powering directly to windward under the sole power of the wind

...from another forum on multihull craft

Originally Posted by David N. O'Steen

So this Dutch artist has created a beautiful propellor-driven skin-on-frame trimaran that only goes directly upwind, without human crew, and set it underway in the western Pacific.

A fascinating project; be sure to check out the construction photos. Some interesting ideas, to be sure, and good for her for actually getting the thing built and launched.

www.windvinder.com

Somewhere in the Pacific Ocean an unmanned “windship” makes its way through the waves - almost transparent, people say, wings everywhere… and it is headed, without a doubt, INTO THE WIND ! With three prows pointing straight into the wind it is underway across the world’s vastest ocean, following every windshift. No one knows how long it’s been travelling. People laugh at fishermen who talk about having seen it.

But there it appears again; all but silently it moves through the swell, as if drawn by an invisible string: on an impossible course

[brian eiland]

I couldn't help but think maybe we can use this technology in combo with the kites for all around wind-assist of our
New Age Trawler/Motorsailer; Kite-assisted

[Daniel Noyes]

Does it really sail forward through the water, into the wind or does it drift backwards more slowly than it would if the propeller was not turning?
Dan
http://dansdories.googlepages.com

[Guest625101138]

Here is more on upwind sailing with turbine:
Windmill or Wind Turbine- powered boats: how many are out there, and are they viable?

And this one is even more interesting on directly downwind faster than the wind:
DDWFTTW - Directly Downwind Faster Than The Wind

RickW

[Daniel Noyes]

Hi Rick
any more info, I have not heard of this before and most of the sites on it look like pseudo science, kind of.
here is a youtube video proporting to show up wind sailing but the sailor keeps tacking the boat through the wind, not really going directly into it.
http://www.youtube.com/watch?v=NNbNNSDljGI&NR=1

Dan
http://dansdories.googlepages.com

[Guest625101138]

Originally Posted by Daniel Noyes

Hi Rick
any more info, I have not heard of this before and most of the sites on it look like pseudo science, kind of.
here is a youtube video proporting to show up wind sailing but the sailor keeps tacking the boat through the wind, not really going directly into it.
http://www.youtube.com/watch?v=NNbNNSDljGI&NR=1

Dan
http://dansdories.googlepages.com

Dan
The most covincing into the wind vehicles are land based. There are many examples of turbine boats discussed in the archives here as well. Here are reference to the best land vehicles:
http://www.clubofpioneers.com/blog/v.../comments/616/
and here:
http://www.windenergyevents.com/Picture%20gallery.html
If you google racing aeolus or look through the various turbine threads you will find a number of references with videos.

I built a model boat with turbine that sailed poorly directly to windward many years ago but I could do a lot better now with what I know about blade design.

I do not think it is a sound stand alone technology though. But tied to battery storage and with electric collection and propulsion it looks good even allowing for the electrical losses. The big advantages are that you can store energy whenever the wind blows even when at rest; you are not tied to the wind speed so the boat can move at a steady pace rather than having speed fluctuation and you can link it to other electric energy recovery such as solar collection.

[Earl Boebert]

There's a model like this (air turbine blade directly connected to water propeller) in the model room of the Herreshoff museum. When I was doing research there a decade or so ago, the then-curator (the late and much missed Carleton Pinhero) told me that at one time Ted Turner bet Halsey Herreshoff a dime the thing wouldn't work. They took it out to the water and it did. FWIW.

Cheers,

Earl

[brian eiland]

Thanks Rick,
I knew there was a lot of discussion that had occured on this subject, but overlooked finding it prior to my posting.

Thanks Earl,
That Herreshoff was an amazing guy.

[Daniel Noyes]

Ok some anecdotal evidence,
I am still interested... I am having a tough time thinking through this... If the blades of the wind mill are generating more lift (drag in a rottary motion) than drag backwards it would seem the boat could propell it's self forward, but if the total drag backward on hull and rigging is greater than the power generated by the blades the boat would drift backward... albeit slower than if it was blowing down wind without a prop in the water...
Is there any video of Windvinder sailing into the wind???
The artist must have taken some footage of the Windvinder sailing into the wind before sending it off over the horizon!
Dan
http://dansdories.googlepages.com

Ps that sailing faster than the wind thing on the tread mill is real fun!

[Windmaster]

I am the sailor in the youtube video http://www.youtube.com/watch?v=NNbNNSDljGI&NR=1 I can assure you that the boat would sail directly into the wind - really it should be obvious from the video, but I have found in the past that any little excuse to claim that it is not working is always found.
At this time I have several model boats that display amazing directly into the wind capabilities.

They do not suffer the complication of storing up power into vast arrays of batteries but work directly in that the wind-rotor is directly connected to the water-propeller. One model I have has only 1 moving part. Some of my work is secret at present.

My practical experiments, which have been ongoing since 1984 show that you can throw all the theory about airfoils and Betz limit out of the window. Even the recent Wind Energy Event competitors have got things wrong!

I can prove all this by demonstration, but only to selected applicants.
I anyone requires further information please fill in the enquiry form on my wingsail website http://www.sailwings.net - you may be required to sign a confidentiality agreement.

[Windmaster]

Hi All

Reviving this old thread I felt appropriate because I have recently done some more tests on sailing directly to windward with a video on Youtube.

You can check them out here: http://www.youtube.com/watch?v=8Rw_qJytbG8

Or search Youtube under "Overcoming the wind"

[Windmaster]

Originally Posted by Daniel Noyes

Hi Rick
any more info, I have not heard of this before and most of the sites on it look like pseudo science, kind of.
here is a youtube video proporting to show up wind sailing but the sailor keeps tacking the boat through the wind, not really going directly into it.
http://www.youtube.com/watch?v=NNbNNSDljGI&NR=1

Dan
http://dansdories.googlepages.com

That was me on that boat! Maybe this will convince you.

http://www.youtube.com/watch?v=8Rw_qJytbG8

Or search on "Overcoming the Wind"

[kerosene]

the answer lies in P=FV Power equals force(thrust) times velocity

Lets Pick a scenario wind of 5m/s and boat travels into wind at 5 m/s thus apparent wind speed is 10m/s. Lest also pick a number for the turbine drag (what number is irrelevant here) lets say its 10N

from P=FV

Power at prop: P=10N*10m/s = 100w

now how much force can that give to the water at lower speed. F=P/V
F=100w/5m/s =20N

So at 5m/s speed in water directly into 5 m/s we have clearly excess power/force to be wasted in inefficiencies (hull drag, prop inefficiencies etc.)


Basically you have a surplus of force as the relative speeds of mediums is different.

[latestarter]

I am afraid there is a flaw in your argument. By choosing different speeds you get a ridiculous result.

Assume a wind of 10 m/s and the boat has not started moving. Your equations would become


Power at prop: P=10N*10m/s = 100w

now how much force can that give to the water at 0 speed. F=P/V
F=100w/0m/s = infinity.


I have to go now but hope to post later why these craft go directly into the wind.

[kerosene]

well that is how the physics formula goes - I didn't come up with that.

Why you don't get insane torque at very slow speeds? I think it all has to do with prop slip etc.

Still its all about leverage. The idea is that the whole system works more or less like a transmission. You reduce the speed for higher torque.

Likewise if you had infinite reduction gear you could get infinite torque - obviously in practice its not quite the same.