Soft Wing Sail

[rhiemstra]

Hello fellow boatdesign-enthusiasts

I am currently develloping a new type of soft wing sail. It's a double sided
sail with battens, using the force of the wind to create an efficiant asymetric wingshape.
I can't give away to much at this stage of the process, but I can tell you the
project lookes very promissing. If the concept works propperly, and I think it will, it will be a sail with the efficiency of a wing and the practical advantages
of a normal sail.

I bougt a hurricane 5.9 catamaran to test it on. currently I am building the special mast. I'm planning the project to be finished januari 2007. And if testing is succesful I will contend in the Catamaran Texel Race.

I will keep you posted

[frosh]

This has potential to revolutionize sailing rigs for all types of high performace yachts. However it has not been perfected yet and therefore has so far only been suitable for a very narrow range of boats. Are you aware of the previous thread on this forum: http://boatdesign.net/forum/showthread.php?t=603
Please keep us posted with regular updates and photos if possible.

[safewalrus]

A double sided sail - wow! I thought all sails had two sides?

Without being too flippant I would counsel against wasting time reinventing the wheel, as it were. Whilst I am not against redesign or redevelopement of any description I am a little concerned that a lot of this revolutionary stuff (and not just only sails) hs only a limited use, but is billed as the wonder stuff that the world can't do without and how in heavens name have we survived so far without 'X' which was only invented yesterday - and will incidentally make the inventor a fortune or at least improve his ego so much he'll be unbearable!

having said that many small developements can and will improve the whole so go for (with the above in mind!)

[Tim B]

Sounds like a good idea in concept, but you will need some very advanced ( CFD-FEA coupled ) analysis to get it to work well.

Keep us posted,

Tim B.

[Andy]

You should check with the patent office - there was a website a few years back about a design (which I think was patented) utilising camber inducers which rotated around the mast. The forward end of the camber inducers was ahead of the mast spar and the sail was sleeved over the whole, including 2 battens per camber inducer (1 per sail surface). The result was a 3d adjustable camber wing with the leading edge just ahead of the mast, and it looked very good although I lost the link in a computer crash. I think the guy fitted one of his wings to an 18 foot skiff tho. There is also this site http://www.wingsails.com/ which you might want to look at.

Andy

[rhiemstra]

Hi Andy,

Thanks for the advice. But I already did exactly what you wrote. I know there has been a lot of research from a lot of people from the 1960's to now. And there are a lot of patents on the soft type wingsails.
Most of them include 1 sail which rotates around the mast (like the one from www.wingsails.com) with the ends at the trailing edge fitted together. With this type of sail it is impossible to wire the mast and hoisting the sail and letting it down again can pose problems when conditions are not ideal.
My design consist of to seperate sails using the mast as the leading edge.
I have found a way to create an asymetric wingshape, using the force of the wind, with special battens. This way wiring the mast can be like it is done on the rotating masts on cats; and hoisting and letting the sail go down again is done exactly like it is done with a normal sail. By the way reefing is also done like on a normal sail.

In a few months I wil send some foto's of the mast and when I have finished and if succesful patented the concept I wil show you the concept with foto's and so on.

[Guy01]

Check out the uni-cat for its wing sail.
Happy to send details if needed.

[rwatson]

Originally Posted by rhiemstra

I am currently develloping a new type of soft wing sail. It's a double sided
sail with battens, using the force of the wind to create an efficiant asymetric wingshape.

It will be interesting to see how it turns out.

The same concept was developed, patented and dissappeared about 10 years ago in western australia.

I hope you have better commercial success

I found a version of the concept here as well
http://marine.bdg.com.au/spitfire_features.html

[Guy01]

The Uni-Cat sail differs from the spitfire in that the system has no boom and rotates just forward of the centre of pressure. The low rotational forces enables it to be lower for less heel.

[Asleep Helmsman]

There was a two year gap in the post; what ever happened to rhiemstra, and his sail.

Too bad we never heard from him again. I would like to know how it turned out.