Soft Wing Sail

[Pericles]

From Duckworks, details of a Wing sail from Israel.
http://www.omerwingsail.com/

Pericles

[brian eiland]

That's rather interesting Perciles, particularly as I consider the DynaRig concept.

But I think maybe you should post this over the Sail Aerodynamics subject thread (or at least another reference to it), as it would reach many more participants who already have a great interest in this subject.
http://boatdesign.net/forums/showthread.php?t=457

We should also invite the inventor to participant in the discussions...what you think...send him an email

[Pericles]

Hello Brian,

Have posted as suggested. I shall try an email invitation.

Regards,

Pericles

[Ilan Gonen]

Hi Pericles
Got your message. Ready to share any information you would like to have on wing sails and on my "omer" wing sail.
Ilan Gonen

[Ilan Gonen]

Hello Pericles and Brian.
Got your message. I am now on the net, ready to share any information you would like to have about wings and "Omer" wing sail.
Ilan Gonen

[yipster]

wow, welcome to these forums Ilan!
been readiing your site and like what i see.
sort of a princeton set-up you sail right?
have a look at my gallery, and see the links bout blow-up wings
and - as expert let us in on your thoughts
more questions to follow

[mydauphin]

Yes, I am interested too.

[Pericles]

Welcome Ilan,

You will find this site is certainly THE place to share and gain information and make friends. Best wishes.

Regards,

Pericles

[Ilan Gonen]

Thanks for the warm wellcome. Sounds interesting.

[Pericles]

Ilan,

Brian has a very interesting thread.

http://boatdesign.net/forums/showthread.php?t=16276

Pericles

[Ilan Gonen]

Thanks. I'll look into it.

[Ilan Gonen]

Thanks to your invitation, I went through the threads and the web sites. I admit it was my first time to see it and I loved very much the ideas, the knowledge and the motivation to change and find better solutions. Great!!

I would like to try to explain in short, what were the thoughts that led me to develop Omer wing sail.
As a sailor I always felt that a lot of wind power is wasted on heeling and on lee way, and we use only a fraction of it to drive the boat forward. The two main reasons for that are: a: the lift / drag of the sails and b: the fact that the sails are attached to the boat in a way that does not enable to really have the right airfoil shape of the sails in all wind direction.
The solution for better lift and less drag was a wing and, for different wind directions was a rotating wing.
I also wanted the wing sail to be simple and to be the right solution for every sailor. This goal led to a soft wing sail that can be hoisted and reefed, rather than rigid wings that are much more aerodynamically efficient but are not good enough for any other purpose but racing.
Of course, the problems were how to do it. The way I found the most effective was to use battens to hold the aerofoil shape. These battens are attached to what I call "sliding spreaders" (please have a look at the web site in order to better understand it) that go up and down the mast while hoisting and reefing.
The camber of the wing is very easily controlled and trimmed (left, right, and rate of aerofoil asymmetry) by changing the angle between the boom and the mast.

The results: much more efficient rig (in all wind directions) in terms of boat speed as well as up wind performance, very simple to use and, easy for short hand sailing. (Better pointing is achieved since the wing's working angle of attack is 8-20 degrees while sails working AOA is almost double as much).

I assume that that’s should be enough to start some exchange of thoughts and ideas. You are welcome.

[mydauphin]

Question to all... How do you calculate the power of a sail compared to horsepower? I know how much hp I need to drive my boat a certain speed. How do I know how much sail I need to do same?

[yipster]

Ilan,
My compliments for your leading edge achievement!
Not all that easy breaking new ground and gettin it discussed.
I find it looks, sounds, and you say it sails good nice to hear.
Thanks for the compliment above and sorry for this late reply here.
I’m by no means an expert on sails and wings but I’m learning.

A few general wing sail questions.

Is the wing sail as good for cruising as it is for racing?
Wing area can be smaller than standard sail and handles easier?
Is a adjustable camber wing good for various speeds?
Really much less heeling with better lift / drag proportions?
Can the Omer wing reef and sail with some spreaders down?
Cord camber batten adjustment keeps fabric tension?
Do wing sails already find general acceptance?
Good self pointing on winds without tail wing?

All the best and like to hear more on soft wing sails

[Ilan Gonen]

Thanks Yipster

The wing is dual purpose. If you are a cruiser, you can either have a smaller wing or you'll just have more power to drive your boat. I, as a cruiser, would like three features of the wing - a. sailig faster b. very easy to handle short hand sailing c. less heeling.

Yes, the sail area (one side) is about 82% of the standard sail area of this boat and, there is no need for any extra sail, nor a spinnaker.

The camber is very easily adjusted. I adjust it to fit the wind velocity (strong winds - close to symmetrical airfoil and in light winds - assymetrical). Also, when tacking up wind, the only change in wing sail trimming is changing the camber from one side to the other.

Reef is done like reefing main sails. It keeps the aerofoil shape the same way it is done when hoisted it all the way. Have a look at the web site gallery, I have put there pictures of reefed wing.

Yes. the battens keep the airfoil shape and sail cloth tension.

I don't think there is general acceptance. We need more time for the conservative sailors, however, I get a lot of letters from interested peple.

Self pointing is related to where the center of effort is. Changing camber takes it well aft the mast and the wings rotates nicely into the wind.

Best regards

Ilan