Im building a wingsail for my kayak/tri CLC sailrigand need some help designing an easy and simple control mechanism for the flap, or second element.
The sail is constructed around a Sunfish mast section, well an aluminum tube that is the dimensions of the Sunfish mastbut is 14 ft in length.
The sail will be 12 ft tall using two sections which are NACA foils shapes 0012 for the main(3 ft section), and 0009 (22 inch section) for the second section, or flap.
My wish is to have a control arm on the second section and a "one string pulls all" led to a pivoting exit block off the main element. This one line would be a camber limiter and adjustment, so not only could I pull it to increase camber but it somehow would limit the camber as well.
I can figure it out with two lines but wanted to pick your engineering brains for an easier or one line solution.

Try here. This is a local retired guy.

http://forums.sailinganarchy.com/in...e=search&do=search&fromMainBar=1

This was sent out a while ago by Steve Clark.

A sketch I did a while ago explaining how the AC 45 worked

Generally speaking C class wings work by limiting camber, basically like an outhaul.

I'm not sure if the above links are working. If not send me an email to chris (at) ctmd.com.au and I'll send them to you.

Chris, thank you!
My thought on only limiting camber is sailing in light wind and the wing "wanting" to go back to a neutral position, similar to light air sailing a cat where the mast wants to rotate aft instead of over-rotating. Many of us light air sailors have an over-rotator specifically for that purpose.

Any hope for pics of the build as you progress? This is highly interesting you know..

Bunji's ala the Hobie 17 mast rotation system should solve that.

Rolf, I put pics some on my Flickr page, go here
DIY kayak Build

I havent started the wingsail other than the patterns for the wings to date, just trying to get everything built for the trimaran for New Years day regatta. I acquired a 1967 sunfish and its rig last night, so the rig will go on the boat until the wing is built and tested.

Jake, bungee may be the easiest way to go, thanks, didnt even think of it, and I have used alot of bungee on rotators in my life...

Thanks Dave.

What CLC model did you build? I did the Chesapeake 17 some time ago and still use it every summer.

John Eisenlohr builds wings for landsailers and iceboats, and has a yahoo groups wing boats blog that might be helpful to you.

Dave

Rolf, I built the Kayak from some "free" plans off the internet, it was the Squeedunk 16 I believe, but it ended up more of a free style build. next time I will build from real plans...I did purchase the sailrig plans from CLC, nice drawings and 2 manuals came with it, one a generic stitch and glue construction manual and the sailrig manual. They really do a nice job with their plans at CLC.
Dave, ive watched all of John's wingsail builds and am incorportaing the hinge method he shows, and some of the contrustion techniques from his SR49(?) Ice boat/land yacht wing, he does some fabulous woodwork and has done alot of testing on the shapes in his "homemade" wind tunnel, good stuff on youtube. I saw you in his video sailing the SC20 as well, I was glad to see some soft water sailing!
The wing for this kayak will be similar to, or from plans from the laser x wingsail that Chuck taylor is building out of carbon. He is working out a few enhancements on the sail and will have it ready for sale next month(January), so looking forward to working with him on this. Im not sure this will ever work for a cat(ala ben halls wing on the A), but it hopefully will work for the little tri, I personnaly think the delicate nature of the sail will be prohibitive to most cats, and maybe to lasers so thats why I think it will be good on the little tri.
http://www.solidwingsails.com/

Dave, a piece of shock chord on the top and bottom of the rig will make it try and stay cambered.

Air-pressure is gonna make the second element WANT to always
find O-deg AOA , IF it's hinged in the proper location. I
know this from flying Rigid-wing Hang gliders that have
a flap.
https://www.google.com/search?q=Exxtacy&client=firefox-a&hs=hUt&rls=org.mozilla:en-US:official&channel=np&source=lnms&tbm=isch&sa=X&ei=GtLKUsiEJs34oATarYGQDA&ved=0CAkQ_AUoAQ

I would want that second element to go to neutral, whenever
i sheeted OUT the main sheet, the flap adds Copious amounts
of lift, that i'd want to go away in a gust ; so a quick release would be Great!

Why so thin on the airfoil ? My Exxtacy is 14% cord thickness,
and it will do 80mph ; pull the flap-cord, and i can land
it on one foot, (and it's a Fake leg at That !!

Bille

Bille, good advice, I modeled the foil from John Eisenlohrs ICe boat wing which has a much higher top-end, so the chord is probably thinner than I need for a little trimaran.
What do you suggest?

Thicker ; you got a Lot of drag on those hulls , so
up to 18% if Ya wanted , Probably 15-16% would be Good !!
Your Hulls are slow ; so the wing should match the speed
of your hulls.

Seriously though my Rigid wing can do 80mph with a 14.7%
thickness of cord. You need what, 20 max ?

Bille

What did you decide to go with ?
I'm Majorly interested in your work !!

Bille

Found some good stuff in SA archives,
'Steve Clark', on 18 Nov 2010 - 12:48, said:
I try to answer questions. Please understand that while I have been doing this for a long time, I do not have reams of data comparing one wing section with another and confirmation that the on the water performance validates the predictions. We just haven't had the time, money and inclination to work that hard. We are pretty smart and we take what we feel are logical steps, but we simply don't have an "optimal" solution. We have "what we have done" and "what works".

1) What has proven to be the most effective section shape used for the main wing? Is it a standard NACA section? If so, # please?
The current #1 elements have been reverse designed using XFOIL or other proprietary foil design software. This has lead to foil shapes that are blunter than the standard 000 NACA series. Cogito's #1 element is 19% section. So is the X wing. Magnus Clark reduced the thickness of the Canadian wings based on a study he did using XFOIL. He has not shared this with me, but from what
I HAVE seen, I am not convinced that he is right and am not scampering around the change my wing shapes. A NACA 0018 WILL NOT BE A BAD CHOICE. It is close enough, but
increasing the LE radius makes the wings a bit more stall tolerant, you can do this yourself or you can wait and plot out the nose sections on the plans.

2) Should the rear flap be of the same section shape? If not, which section has proven most effective in that role? Is it a standard NACA section? If so, # please?
The trailing edge flap is not the same section. I have used NACA 630A10 and NACA0009 sections. Tom Spear makes an argument for NACA 0012 sections. There are quite a few practical compromises in the flaps and I think any of these sections is fine. The thinner sections will provide a smooth leeward side at a lower flap angle.

3) Should the main wing and rear flap be 50/50 area wise? Or should it favor greater area in the main wing? If so, what percentage would be the optimal split?
Current wings are pretty much 60-40 splits. We have the #2 at about 20% of #1 as well. The placement of the pivots along the fore and aft axis of the wing determines the lateral displacement of the flaps at various flap angles. This is a fairly complex compromise.

4) Is there an accepted method for the control systems? If so, are there articles/drawings/photos on the web detailing the principals and execution there of (links please)?
I have DXF or PDF file of what has become the standard control system. This was invented by Dave Hubbard 490 years ago and developed over 10 wings or so by the Patient Lady Team. I believe thay wings are only as satisfactory as their control systems. This is the only one I can say is dead nuts reliable. Send me PM and I will send you the file. Specify format please.

5) Since rigid wings are more efficient, can the total sail area be reduced to achieve equal or greater performance over a soft sail on all points of sail? If so by what percentage can it be reduced?
In theory, but most of the design work has been done to provide more power for equal area. I actually look at it the othr way: since wings can be so much cleaner and can be depowered more effectively than soft rigs and sails, how much could their area be increased? Can this increase make light sails unnecessary? My current best guess is about 25%.

5) What is the optimum aspect ratio?
Wings are not subject to the same constraints that sails are. They can be taller and narrower, however the vertical CG of the vessel and thus the stability of the vessel is effected by the rig height. You have the competing values of center of effort height and aspect ratio at play as well, so this is a hard answer to give. C Class wings have been about 40' tall for 300 square feet.

6) How low can the aspect ratio be pushed before there is an appreciable drop off in performance?.
In catamaran sailing there is a big performance increase associated with flying a hull. So being short doesn't pay until it is blowing pretty hard.

7) Is there a proven optimum side profile shape? Some variation of quasi-eliptical. What we have done is some form of taper. It is usually simplified for ease of construction.

8) What has proven to be the best method of inducing twist into a rigid wing sail? BMW Orical AC tri appear to have 9 seperate adjustable sections on the rear flap, Is there a way to mimic this on a smaller scale and be mechanically controled for twist? The Oracle wing controls were losely based on the Patient Lady system. PM and get the drawing.

SHC

Also Bille, this is for you,

http://www.tspeer.com/RigidRigs/50flap/S901fa20.htm

My wingsail build is progressing, making some errors in the building of the ribs, but each one is better. Im on #4, quit vacuum bagging after #2, hand layup with wax paper is providing a smoother build believe it or not.

The leading edge of the 1st element was built using a jig, which really is a simple curved section about 3 ft in length. I lay up a 3 ft section at a time and then epoxy them together. The 12ft section is around 4#'s, and is quite strong. Its not really structural per se as I will have a mast thruogh the ribs that wil provide the structure.
more to come...