# Modern days sail technology

Let’s see it then. Saying it doesn’t make it so. I didn’t find a single example of a symmetrical airfoil on a winglet. . In the mean time, I’ll stick with NASA. You know, the guys that developed the things.

The diagram came from here:

The idea came from NASA.

Yes angles. The winglets are set at specific angles to the wing. Not 90 degrees. The precise angle is critical for performance. And yes. Heavy research as this is specialized stuff. If you search WINGLETS CAMBER you’ll get a start. Also WINGLETS “INDUCED VELOCITY”. The results will include scientific papers.

Like this one: 19760019075.pdf (1.6 MB) Search for CAMBER within the paper. You’ll get right to “camber significantly greater than that for the wing.”

Airliners don’t typically use symmetrical airfoils, if ever. They generally use supercritical airfoils. Stunt planes use symmetrical airfoils so that they can fly well inverted and roll cleanly.

Edited.

You still don’t get it. You are confusing camber with aspect ratio. Camber is used to maximize disruption of vortex. Aspect ratio is used to maximize lift. Creating lateral lift at the wingtip would introduce drag and defeat the purpose. You have a long way to go before you understand the science. Quoting papers on the subject is not providing you with the understanding of the key principle of lift. You’re in over your head, study the basics.
Still waiting for you to illustrate how a foil can produce forward lift directly upwind at zero AOA…

Going down swingin’ huh? Camber is the curviture of the wing or airfoil. Basic stuff. Camber (aerodynamics) - Wikipedia

Why are you harping on this? The whole point is that the airfoil of the winglet is NOT symmetrical. You do know that airliners DON’T use symmetrical airfoils don’t you?

And another strawman. I have years of aviation training and a license to fly them. Do you?

“A little learning is a dangerous thing;
Drink deep, or taste not the Pierian spring:
There shallow draughts intoxicate the brain,
And drinking largely sobers us again.”

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FYI; The subject is about modern day sails, not winglets on jetliner, which is interesting to aviators but has little to do with propelling ships by wind power.

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I agree. I didn’t introduce the aviation angle which is only of academic value to the subject of wind assist for vessels but was bothered by a simplified premise put forth as a scientific fait accompli. In hindsight, I should have ignored it.
No hard feelings for @CoastalTrader who I hope didn’t take offense.

No, never ignore an academic challenge.
You could have moved it to another thread though. (In Scuttlebutt maybe?)

OOOPS!! I should have followed my own advice and not challenged Bayrunner in the Texas Cold Snap thread

No worries. The intention was only to advance a theory by which the ship’s “Turbosail” might possibly gain a passive advantage when ambient wind was not present.

Same with having cranes onboard. You learn to deal with it

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"An AOC is necessary to create lift. "

…what do politicians have to do with lift?? Hot air from their empty rhetoric?

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Not news that this was under discussion, but now there is a schedule for the project:

I know, I know. These idiot, who don’t know nothing about sailing, or the shipping business, are wasting their time and money on something “everybody” know is a stupid idea and cannot be done economically.
They should just do things the good ol’ way and not making a fool of themselves.
There you go. Now I saved Jughead from saying so.

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