Select to expand quoteNelsonFoils said..
ARC
If you can find the time great .
Nice work you have done .
Love your workshop ! and what you make in it .
First of all , let's make it clear, I'm not smartest guy in the room. My design is sequence of wing sail development based on research and development made by others. As I said before , good ideas never grows in one place and fully mature. 2 years ago me and my partner Alex, we went trough many others published ideas, and I'm pretty sure that I saw this drawing before. I's not only you, Nelson Foils, also many other people fall into thinking, that wind, is going to blow airfoil into desirable shape. Actually it will do exactly opposite. Simple rule, body in rest want to stay in rest. Difference btw wing sail and conventional sail is that wingsail do not fail in high loads and will take much more abuse. In your drawing you put spreaders btw battens, where you hope ,that wind pressure would displace battens in desirable airfoil, meaning your airfoil depends on wind speed , humidity, temperature, altitude, weight of the sailor and quality of hydrofoils, all with high loads? Remember Harrison Ford in In 6 days 7 nights? This is the island, If you want it here , you bring it here. Same with airfoil, If you want specific airfoil, you put it there and enforce it. On top of this , reliability of the structure, you have 6 battens, each of the batten has 2 pivoting joints and 1 attachment on the front, it makes 36 total points of possible failure. So reliability of your structure will be as good as one of 36 joints. Let me put cherry on the top of the cake, how do you waterstart that thing!? What happened in case of hard crash with 36 points of failure?
This is how I solve this problem. My mechanism located under the boom, it makes virtually inaccessible to impact , plus it has only 3 parts, each part has long slut for shock absorbing. But even If mechanism goes to total fail, you still able to sail back to shore , with less efficiency. Top of the sail has 3 independent air-filled balloons between panels, it's like triple safety system. Aerodynamically, sail designed to hold its shape in hard condition, meaning, harder it blows, sail become stiffer. I think, I'm pretty sure, that this system will revitalize sport and bring more youth , because it will make it easier to learn and safer to sail.
Select to expand quote ...each part has long slut for shock absorbing...
Now you have my full attention! 
I honestly hope these sails kick arse windsurfing needs something new to move ahead in performance, pity you weren't on the West coast Stanley I'll be over there in August would have loved to give your sail a try.
Select to expand quoteMan0verBoard said.....each part has long slut for shock absorbing...Now you have my full attention!
Yep and..... " harder it blows, sail become stiffer " 
I'am glad you came across the same problems as I did over the last 20 years , and you found your way to deal with it , great , bravo !
But there is allways more the just one way to solve the problems .
My wing is not shaped just by windpressure but wind gives the impuls to it .
Sorry for my French ...;-)
Select to expand quoteNelsonFoils said..
I'am glad you came across the same problems as I did over the last 20 years , and you found your way to deal with it , great , bravo !
But there is allways more the just one way to solve the problems .
My wing is not shaped just by windpressure but wind gives the impuls to it .
Sorry for my French ...;-)
i don't see it how? I see in the boom area when you outhaul pressure will equalize on both panels and sail become symmetrical.
But anyway, good luck with your development.
The one thing was to keep it simple .
Not like good old Tiga shaper HdT
Gerrit, how far down the track is your design, when do you expect to see it in production?
this is all exciting windsurf news, I didn't realise there was so much development going on.
Production ? Like in China and marketing company's , teamriders etc , billion dollars investment , logistic's ...
No way .
I finaly got a very competent sailmaker to work with and we are talking about what kind of monofilm to order...
I hope something like 3 to 6 weeks to finish the proto .
We will make it a " made to order " high end product with room for development .
In the futur ? I don't even know what monday will bring so we will see ...
If there are local sailmakers in your part of the world they can buy the design and make the parts in a local cnc shop buy the right sailbattens end make it .
If you happen to be the boss of one of the big 5 in this industry give me a call....;-)
Thanks
Gerrit
Select to expand quoteNelsonFoils said..
Production ? Like in China and marketing company's , teamriders etc , billion dollars investment , logistic's ...
No way .
I finaly got a very competent sailmaker to work with and we are talking about what kind of monofilm to order...
I hope something like 3 to 6 weeks to finish the proto .
We will make it a " made to order " high end product with room for development .
In the futur ? I don't even know what monday will bring so we will see ...
If there are local sailmakers in your part of the world they can buy the design and make the parts in a local cnc shop buy the right sailbattens end make it .
If you happen to be the boss of one of the big 5 in this industry give me a call....;-)
Thanks
Gerrit
Gerrit, I don't want to kill it , I think made to order is good way to start any business. Good luck with your development
You are the best proof of that yourself , the way to go in a green and social aera .
And I see all your comments as upbuilding , you did a great job on your project ! Keep up the good work man !
Nelson , your rig looks like a copy of Gordon Ross "Powerfoil" which he patented about 15 years ago and he made some sail as well.
And that George Greenough was sailing something similar 10 years before that!
joewindsurfer.blogspot.com/2014/03/wing-sails-aka-power-foil-sails.html
It all started in 1994 with the artical in the French magazine PLANCHE
Wings all have the +/- the same profiles
I only am looking for ways to make theme practical and sailable .
Hello,
Where is your profil Stan ? Do you think He s better than a double symetrical profil NACA ?
Yann
Code for Mast Type Ratio of max boat
speed to wind speed**
A 0.85
B 1.00
C 1.10
D 1.30
E 1.90
F 2.40
** A rough comparative indication only,
as many detail factors are involved.
smalltridesign.com/masts/rig-mast_options.html
Ok !
Concerning speed or stability what is your reference sail ? ( it s not the same if you compare your wing sails to an old wave sail or to a Race sail with 4 cam and double sheath :-)
I don t understand when you say "NACA profiles not really suitable" .... For "not suitable" your talking about solid wing AC45 NZ or profil in general ? And after you say "My profile look more like Vestas Sailrocket" i don t understand that because i confim on my side Vestas's sail is a NACA profil. NACA profil are not necessarily symetricale !
I check the video good to see your sail !
Yann
Select to expand quoteYannFRA58 said..
Ok !
Concerning speed or stability what is your reference sail ? ( it s not the same if you compare your wing sails to an old wave sail or to a Race sail with 4 cam and double sheath :-)
I don t understand when you say "NACA profiles not really suitable" .... For "not suitable" your talking about solid wing AC45 NZ or profil in general ? And after you say "My profile look more like Vestas Sailrocket" i don t understand that because i confim on my side Vestas's sail is a NACA profil. NACA profil are not necessarily symetricale !
I check the video good to see your sail !
Yann
I'm not going to debate about NACA in Vestas, I just say that i admire what they did, also their approach to solve problems should be taken as an example. AC 72 cat is symmetrical profile with flap,HAS NOTHING TO DO WITH ASYMMETRICAL WING. I invented way to change asymmetry in profile using internal components. If you look on my drawing where i describe advantages of the wing, on lover portion you'll see profile that i use.
The main advantage of a solid foil is the drag is much lower when not working at designed angle of attack. But most windsurfers are very good at keeping a single surface foil at its optimum AoA at which it provides more lift and no more drag than a solid double surface sail. The blue line on polars is the e376 , the tan one is the naca
IT STARTED FOR ME IN 1994 people have put all kinds of wing on all kinds of board from day one in the afternoon ...
Did you read http://www.avweb.com/news/airman/183261-1.html?redirected=1 ?
It is not about keeping a windsurfing sail at the optimal AoA it is about what happens when its not ! Then the cruved shape of the intrados get you in big trubble .
The NelsonFoils wing starts to create lift from AoA 0.1° , is ideal at about 8° to 12° and only gets you in danger at +35° .
A old school windsurfsail at less the ideal AoA only makes you turn upwind , so you have to close the sail in a brutal way and need al lot of twist in a gust or you have a spinout .
Have a nice day
Gerrit
“Faced with the choice between changing one’s mind and proving that there is no need to do so, almost everyone gets busy on the proof.”
Great thread.
From a marketing/layman's point of view what are the advantage of the wing sails for sailboards (not boats)? Wider wind range, less drag, increased stability, smaller sail for given wind (does a 5m wing generate same power as 7m traditional race sail)?
Any session speed results from these wings?
Select to expand quotemkseven said..
Great thread.
From a marketing/layman's point of view what are the advantage of the wing sails for sailboards (not boats)? Wider wind range, less drag, increased stability, smaller sail for given wind (does a 5m wing generate same power as 7m traditional race sail)?
Any session speed results from these wings?
MKseven.After 2 years of experimentation, 5 m wing is not going to generate more power than 7 m traditional sail. The difference is, that your 5 or 7 m sail will fail at some point of wind increase, wing is not failing. Let's say 7 m wing will perform just like your 7 m , and it will continue perform in condition when you need to change to 3 m. So 7 m will generate more power than your 3 m, resulting in more speed. Oh yeah and it handles much easier, no sudden pulls of sudden lift lose, very consistent pull , no spin outs, no back leg pressure. On top of it my sail floats, you can crush just like traditional sail , fall on top of it, no problem at all. During all my experimentation i broke 2 battens and two defected cam holders.
Select to expand quoteyoyo said..
The main advantage of a solid foil is the drag is much lower when not working at designed angle of attack. But most windsurfers are very good at keeping a single surface foil at its optimum AoA at which it provides more lift and no more drag than a solid double surface sail. The blue line on polars is the e376 , the tan one is the naca
This is nice profile you showed there! For wing sail , front needs to be more pointy and lower surface need to be just a bit curved out. I have hard reversible sail structure for catamaran use, featuring exact profile execution, simplicity, durability, easy part changes, and twist control. Last year,built scale model , showed to C- class AC guys, they eyes pope out. But can't get any funds in US to execute it.
Select to expand quoteyoyo said..
Cool, love the tell tales.
French people very innovative! It was good idea,but not fully developed, left behind a lot's issues to resolve.
Really interesting project, I hope it develops into something significant, and then accepted industry wide.
Just thinking out loud here, and I write from the perspective of a potential consumer/buyer, and not a technical or scientific perspective. I was wondering what would be needed for it to attract people away from traditional sails. I dont think the enthusiasm of the developer will be enough (Sorry Stan but its the truth).
What I see with traditional designs is that people are generally very happy with them. They rig easy, they are very controllable, they have wide wind ranges, they are fast with many GPS speedsailors having broken the 40kt barrier, (just to mention what comes off the top of my head, but 4 crucial ingredients).
So this new sail has at least these 4 elements to compete with? ATM the new sail sounds at least slightly more difficult to rig, and as Stan has admitted at times it hasnt been rigged correctly, so at worst it is much more difficult to rig in this early stages of its development. Controllability? Stan is claiming they are more controllable, at the same time he is also honest and admitting he is having troubles at the higher end of the wind range, so this still needs to be fixed. Stan claims these new wing sails have much wider wind range, so if true, this is a definite advantage, but not enough if other areas are not fixed. Speed, atm Stan is claiming they are not necessarily faster than traditional sails. The speed issue is critical here because GPS speed sailing is one area where these sails could be marketed and if he could demonstrate a true (at least 5%) speed improvement at the top end of the range eg (40kts vs 42kts or 52.5kts vs 55.2kts), then this is where people would buy it for sure, if the rigging, controllability and wind range issues are sorted.
Keep going Stan, I hope you can get this to a level where you are confident to give a sail to a top professional like Antoine who can set a new world windsurfing speed record, and you'll sell thousands of these sails world wide!!
