Does anyone know any good sites for tips on building solid aerofoil sails. Or have any tips on making an efficient asymetrical solid sail?
One of the most knowlegeable people in the US on wing masts is Bill Korsgard; he is a member here you can look up his e-mail and contact him. He has done many experiments with land sailer rigs and ice boat rigs.
You can also e-mail me and I’ll give you his e-mail address…
You might also check the multiONE website it seems to me there was some info there but I could be wrong.
Thanks
Hi Eric,
I’ve been building composite wingmasts used in conjunction with mylar sails. The solid chord is 20-25% of the total airfoil chord depth. The model airplane guys have this technique pretty well figured out: http://www.pilotsguide.com/rc/vacbag.shtml . I haven’t done much with articulated solid wings, but just got back from Dry Lake Ivanpah where the landsailor guys held the annual “America’s Cup” regatta. A fair number of the use solid wings successfully: http://www.nalsa.org .
My designs are largely empirically based, but some useful theory can be found at:
http://www.tspeer.com/ and http://groups.msn.com/LandsailerandIceboatdesignandconstruction/messages.msnw
http://www.grc.nasa.gov/WWW/K-12/airplane/foil2.html
Doug, thanks for the comment, but the big boat guys know WAY more about this than me. I’m basically adapting what they do, to something that will work with rc scale & hardware. Because of the potential for significantly exceeding windspeed with hard surface craft (and hopefully multihull softwater boats), the wingmast allows changing amount of draft (camber) needed to efficiently handle the variations in apparant wind.
Regards,
Bill K
www.ircssa.org
Bill K
wow, just looked at some of those sites, always disliked the idea of what a round tube mast does to the flow around the luff of the main … another project on the list… nice one Bill!
Luff 'em & leave 'em.
Thanks Bill.
Whats the amount of force that normal cloth sails generate on a 1m multihull in Newtons?
Is there a pic of a sailboat using a s olid sail? I thought of trying it once?
thx
Except for some possible home experiments, you won’t find a solid wing sail on a monohull.
For multihulls, however, there has been experiments going on around the world. Here is a photo of a French 2 Meter (6’ x 6’ approx) with a single panel solid wing. Going to a multi-panel solid wing allows much more control, a wider angle of attack, and ability to power up or down using cambers between the panels. Because of the great power available from solid wings, a much smaller sail area and lower aspect ratio can be used - and still obtain the same (or more) power than from a soft sail.
Catamaran - design and built by Jean Margail (FR)
Download Attachment: [ smallw23.jpg](http://www.rcsailing.net/forum1/data/f-48 multihulls/2004330215512_smallw23.jpg)
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Download Attachment: [ Smallw22.jpg](http://www.rcsailing.net/forum1/data/f-48 multihulls/2004330215538_Smallw22.jpg)
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By multi panel do you mean multi aerofoil. For example a F1 rear wing? With a large main aerofoil then a smaller aerofoil offset from and overlapping the main wing.
By “Panels” I mean the vertical panels that contribute to “camber” in the main.
A “single panel” like in the 2 Meter photos has a fixed, symmetrical camber - both sides are fixed. Only the angle of attack (front of wing to wind direction) is controlled.
A “double panel” (or more) has vertical sections that act like “flaps” on an airplane wing. By moving the trailing edge of these flaps to windward, you can control the camber and increase it on the leeward side of the wing.
You can go another step by adding flaps to the forward part of the wing that extend out and funnel the air around the leading edge of the wing, increasing airflow and windspeed, much like a jib does.
Download Attachment: [ smWildTurkeyWing.jpg](http://www.rcsailing.net/forum1/data/F-48 multihulls/2004331103521_smWildTurkeyWing.jpg)
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In these two photos, you can easily see the solid, leading edge of the wing, and the moveable second panel (flap) to the rear. This boat only used a double panel, as it was raced single-handed and between steering, sheeting for angle of attack, and adjusting camber and twist, the skipper/owner had his hands full.
Also easy to see the available power compared to the soft sail boat to the right - which has a taller rig. The solid wing has much lower center of effort, to reduce heeling, yet it produces the same or slightly more power from it’s smaller size. In the view looking up, the small black metal piece sticking out is the control arm for camber in the back section of the wing.
Hope this helps.
Try this one.
Check this solid wing rig out
http://www.lacaustralia.com/images/wing_0543_400x300.jpg
Have the aussies got it right???