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
m...
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

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

just dipsquats who pretend to know things they utterly and knowingly ignorant
of.

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.



Jax,
Do you intend to annoy people, or is it just by accident?

JAXAshby wrote:

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.



Jax,
Do you intend to annoy people, or is it just by accident?

I beg to differ.

And someone with the necessary training to make a statement such as yours
would use far more decorum.

Love the 100% refutations! (as above). They really get your point across.
Not quite the point you think you're making, though...



"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

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

ac, beg all you want, but you learned what little have from a popular science
magazine article long ago.

you are an idiot. would you feel better if the world referred to you as a
"special learning" student instead? You know, decorum and all.

From: "AC"
Date: 8/22/2004 11:23 PM Eastern Daylight Time
Message-id:

I beg to differ.

And someone with the necessary training to make a statement such as yours
would use far more decorum.

Love the 100% refutations! (as above). They really get your point across.
Not quite the point you think you're making, though...



"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

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

Oooohh, great - name calling. Now, we're really expressing ourselves well,
aren't we?

I can tell the limitation of your cred's by your grammar. I bet you can't
tell what mine are...

You can click on as many hyperlinks as you want, and be a wannabe pilot all
your life, but still not receive basic physics training, that's a two-way
experience.


"JAXAshby" wrote in message
...
just dipsquats who pretend to know things they utterly and knowingly
ignorant
of.

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.



Jax,
Do you intend to annoy people, or is it just by accident?

hehehe, I bet the group can work out who is the faker...

Go back & hide behind your PC. You obviously aren't supplying the group, or
anyone else anything of use, nor substance.

Why not cut & paste your reactionary diatribe in another newsgroup? It'll
make just as much sense there!



"JAXAshby" wrote in message
...
ac, beg all you want, but you learned what little have from a popular
science
magazine article long ago.

you are an idiot. would you feel better if the world referred to you as a
"special learning" student instead? You know, decorum and all.

From: "AC"
Date: 8/22/2004 11:23 PM Eastern Daylight Time
Message-id:

I beg to differ.

And someone with the necessary training to make a statement such as yours
would use far more decorum.

Love the 100% refutations! (as above). They really get your point across.
Not quite the point you think you're making, though...



"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