certainly no expects you to understand, ac, one liners or ten thousand.

From: "AC"
Date: 8/23/2004 12:13 AM Eastern Daylight Time
Message-id:

Are you the "ng"? I hope not, since if you are, that would make you some
sort of one-sentence-replying dictator, expecting everyone else to
understand your prophetic one-liners.


"JAXAshby" wrote in message
...
ac, you lack totally and utterly ANY understanding of what is going on --
airfoilwise -- on either or, same same, a sailboat sail.

ac, the ng askes that you NEVER post on this subject again. for the
obvious
reason.

From: "AC"
Date: 8/21/2004 5:50 PM Eastern Daylight Time
Message-id:

The answer to your question, is yes. Sails are made from dacron for ease
of
handling & shortening, and cost. Many examples of rigid-wing vessels
exist,
I suggest doing a search on that. They often use fairings at the leading
edge, or movable trailing edges to fine tune the foil.

An aircraft can fly inverted, because its angle-of-attack changes to suit
the correspondingly lower efficiency of the foil in this position. As
others
have noted, acrobatic craft often employ nearly symmetrical foils for
this
reason. A normally profiled foil will fly inverted, but inefficiently,
and
at a much lower VMG due to the increased drag from the higher angle of
attack.

Try some "Bernoulli experiments for kids",and you will reach a better
understanding.

"Axel Boldt" wrote in message
om...
Hi,

I'm trying to understand how a boat can sail against the wind.
Explanations on the internet usually go like this: "The sail has an
airfoil shape, the air goes faster on one side than on the other,
creating lift by Bernouilli's principle." But I know that for flying
planes, the wing's airfoil shape is not essential (otherwise planes
couldn't fly on their back): it's the angle of attack that matters. So
I'm wondering if the same is true for sailing: would it be possible to
sail against the wind with a sail that's a rigid flat surface, not an
airfoil-shaped piece of cloth?

Thanks,
Axel