Wing sail is reality now

[LUCARO]

It took foils ten years to take off

https://www.youtube.com/watch?v=1oyWMusaDTI

just saying...

[isobars]

OTOH, I was both very impressed and very UNimpressed with the Aeroforce Double Luff sail I tested in about 1992. Its luff sleeve extended maybe 1/3 of the way back from the mast towards the leech, and had no bladder.

PRO:
• Completely ignored windspeed fluctuations. Gusts and lulls ceased to exist, as power delivery was like that of an electric motor. Maybe it should have been called the Tesla.

• NOTHING knocked it off its intended course. Point it towards a mark and neither nature nor rider input could deflect it noticeably.

• They're frigging -F-A-S-T-.

• And as steady as a big rock.

CON:
• It took two of us half an hour to rig it. That might be fine for a monk, but not so much for a windsurfer on a windy lunch break.

• NOTHING knocked it of its intended course. Point it towards a mark and neither nature nor rider input could deflect it any time soon.

• Given a few too many seconds in the water after a fall, it was almost impossible to clear the sail for a waterstart before everyone else had finished the race, packed up, and gone home. That giant luff sleeve held scores, maybe hundreds, of pounds of water once flooded.

Someone said this version costs $1,200. That's dirt cheap* considering that (1) this version consists of two complete sails plus a complicated bladder/batten structure and (2) one such sail is a full quiver for most sailors and venues. I need to rig a whole 6-sail quiver of normal sails to enjoy only part of that wind range, and then slog across the wind shadow -- twice -- every time I choose to plug in a different sail. Then I gotta de-rig and stow all that $#!+ when it's time to go home.

* Lessee ... For 14 to 42 kts average wind speed in plug'nplay mode, I'd want about 8 complete rigs at $2,000 a pop. I don't need a calculator to figure out the cost advantage of this monster, nor a clock to figure out its rigging time and wind shadow crossing advantage.

If this thing would only maneuver like a wave sail, I'd be all over it at twice the price.

[alap]

yes it sounds crazy - same sail from 14 to 42 knots. My first reaction was the one of Anton Chekhov's character: it is impossible because it is never may be possible.

and his website is bad, although it does a very good job to obscure the main idea behind his design.
But I googled a bit more, and found couple of his videos and his FB page (and there are the videos him sailing, and his loft, and his machinery, etc.)

And we have to give him a credit, for the idea and for how far he had advanced it.

His main idea (totally hidden from his website) is that this is a double skin wing, totally symmetrical. The surface on the left and the surface on the right with double set of battens. If you make a horizontal cross section at any height it will be an ideal totally symmetrical tear drop shape.

His idea is that this is a solid wing, as solid as could be. Obviously it has some play and it is not clear how much the shape of left side is different from the shape of the right side when you fill it with wind. Obviously it is not totally symmetrical anymore, but if I understand correctly, it is still solid.

If this is true then increasing speed of the airflow 3x times should increase lift 9x times, but this probably can be compensated by luffing the sail (i.e. decreasing this angle of attack, or mathematically speaking decreasing sin(alpha)). However luffing can be done with any sail, and with any conventional single skin sail it is not enough with those drastic air flow changes - the shape will be distorted, the center of lift will move, the pressure on left and right hands starts to wander...

But, and again I hope I understand this correctly, with a solid rigid wing design when the sail shape doesn't change with the gust the center of effort stays in the same spot, it is just that it pulls stronger - and this alone can be compensated by luffing. Like an aircraft wing has the same center of effort no matter whats its speed. And from what I understand this is the main point of his design.

I still have problem believing that 5.8 can be sailed on a single 70 liter board in 14 knots. I'll take Fanatic Ray 145 and 8.5 and I'd need to pump it on the plane in this wind.

Obviously the weight of the sail is double.

And as noticed the rigging is outright insane, I personally prefer to rig three nocam sails instead of this one, and I think I'll be faster.

As mentioned durability is a big Q

And I add the waterstarting - this cavity between skins will act like a huge mast sleeve full with water?

For a single man effort I think he is one of a heroes that move progress forward. But the drawbacks are very obvious

I would gladly try it for free and will write a review - just a great idea and a great effort behind it; but as is I am skeptical...

I would also think that this is a great idea for catamarans

[cgoudie1]

PM me and send me one to demo. I'll even endure the rigging.
I regularly see winds from 15 to 40 MPH (sometimes in the same 30
seconds), so this is the perfect sail. 12 Bills is cheap for a single sail
quiver. Like I said, send me one!

-Craig

[dllee]

Shortboarding since '83, and working at windsurf shops for 21 years, I've known several guys who used a 5.7 sail for all winds from 15 to 40 mph...

[isobars]

I could do that, too.

I could also eat light bulbs, jump off a roof onto an upturned rebar, or, worse yet, sail (slog) a 5.7 in 14 kts of wind. I would do none of them intentionally.

[swchandler]

I have to say that the MWsails.com website only offers me a blank screen, but that might be problems with my computer. That aside (with the help of other's research), I find the overall design is novel, and performance-wise, it might offer decided advantages. Only time will tell where the ideas catch on in the marketplace.

Yet, the testy issues that come to mind are rigging in less than optimal conditions. In any strong blowing dirt and sand environment, the rigging process could bedevil all your best efforts, particularly taking it apart wet without ending up with a bit of disaster. Needless to say, everything must be totally clean the next time you rig.

[killogramm]

[killogramm]

[killogramm]