Flatboarding: the sailing style

In article
,
taichiskiing wrote:

On Dec 24, 10:27 pm, Alan Baker wrote:
In article
,
taichiskiing wrote:
On Dec 24, 9:51 pm, Alan Baker wrote:
In article
,
Richard Henry wrote:
On Dec 24, 8:46 pm, taichiskiing
wrote:

http://pilotsweb.com/principle/forces.htm

Pilotsweb also has a page on Airfoils which includes brief
descriptions of Angle of Attack and Lift. It appears you have not
read them.

To be accurate, that site's description of lift and angle of attack has
diagrams that show lift with no deflection of the airflow.

i.e. completely wrong.

You two too can joint my slap your face challenge on Flatboarding: the
flying style.

That didn't even remotely pass the intelligibility test.

You have failed the "slap your face challenge."


You consistently fail the *language* challenge.


Nevertheless, you remain utterly wrong about keels and wings.

Your pathetic little knowledge gapper netkook's denial doesn't shed
the light.

"When you contradict Newton's Mechanism, you are wrong."

Tell that to Einstein.

But I'm not contradicting Newton's *mechanics*, Chai-tea.

Page 48 and page 51 show and say it all.

http://books.google.com/books?id=kFj...PA51&dq=physic
s+of+sailing+keel+angle+of+attack&source=web&ots=q hVYqWYEDM&sig=DTw-W09hg
iFoTggqJQrUztP0MKI&hl=en&sa=X&oi=book_result&resnu m=2&ct=result#PPA52,M1

And this:

"A Keel is Needed - Without a keel, wind striking the sail would only
move the sailboat downwind. As with the sail, there will be an optimum
angle of attack for the keel as well."

http://sail-boats.suite101.com/article.cfm/how_sails_work

The diagram shows it perfectly.

http://www.suite101.com/view_image.cfm/217685

And this:

A keel works only if the motion of the boat is not exactly in the
direction in which it¹s pointed. The boat must be moving somewhat
sideways. In that ³crabbing² motion, the keel moves through the water
with an angle of attack. Just as for the sails in the wind, that causes
the water on the ³high² (more downstream) side of the keel to move
faster and create a lower pressure. Again, the net lift force on the
keel is due to the combination of that decreased pressure on the high
side and increased pressure on the other (low) side."

http://web.mit.edu/preis/www/18.384/...sical_Applied_
Maths/Possible_Topics_files/Anderson_PhysicsToday_2008.pdf

But tell us all again how you understand this better than physicists and
experienced sailors!

LOL

--
Alan Baker
Vancouver, British Columbia
http://gallery.me.com/alangbaker/100008/DSCF0162/web.jpg

On Dec 26, 12:59 pm, Alan Baker wrote:
In article
,
taichiskiing wrote:
On Dec 24, 10:27 pm, Alan Baker wrote:
In article
,
taichiskiing wrote:
On Dec 24, 9:51 pm, Alan Baker wrote:
In article
,
Richard Henry wrote:
On Dec 24, 8:46 pm, taichiskiing
wrote:

http://pilotsweb.com/principle/forces.htm

Pilotsweb also has a page on Airfoils which includes brief
descriptions of Angle of Attack and Lift. It appears you have not
read them.

To be accurate, that site's description of lift and angle of attack has
diagrams that show lift with no deflection of the airflow.

i.e. completely wrong.

You two too can joint my slap your face challenge on Flatboarding: the
flying style.

That didn't even remotely pass the intelligibility test.

You have failed the "slap your face challenge."

You consistently fail the *language* challenge.

Not really, given you consistently respond to my posts in a negative
way, you understand my language alright, so, it is either your denial,
or you've failed intelligently.

Nevertheless, you remain utterly wrong about keels and wings.

Your pathetic little knowledge gapper netkook's denial doesn't shed
the light.

"When you contradict Newton's Mechanism, you are wrong."

Tell that to Einstein.

Einstein did not contradict Newton's theories, he only extended the
field.


But I'm not contradicting Newton's *mechanics*, Chai-tea.

Not when you said the keel "points at an *angle* inward of the tangent
to the path of the boat." Actually, such a statement only reflects
that you know neither math nor physics.

For how Newton Second Law explains how a centripetal force turns an
object you need to study the portion titled "The forces during a
turn."

http://pilotsweb.com/principle/forces.htm


Page 48 and page 51 show and say it all.

http://books.google.com/books?id=kFj...PA51&dq=physic
s+of+sailing+keel+angle+of+attack&source=web&ots=q hVYqWYEDM&sig=DTw-W09hg
iFoTggqJQrUztP0MKI&hl=en&sa=X&oi=book_result&resnu m=2&ct=result#PPA52,M1

And this:

"A Keel is Needed - Without a keel, wind striking the sail would only
move the sailboat downwind. As with the sail, there will be an optimum
angle of attack for the keel as well."

http://sail-boats.suite101.com/article.cfm/how_sails_work

The diagram shows it perfectly.

http://www.suite101.com/view_image.cfm/217685

And this:

A keel works only if the motion of the boat is not exactly in the
direction in which it¹s pointed. The boat must be moving somewhat
sideways. In that ³crabbing² motion, the keel moves through the water
with an angle of attack. Just as for the sails in the wind, that causes
the water on the ³high² (more downstream) side of the keel to move
faster and create a lower pressure. Again, the net lift force on the
keel is due to the combination of that decreased pressure on the high
side and increased pressure on the other (low) side."

http://web.mit.edu/preis/www/18.384/...sical_Applied_
Maths/Possible_Topics_files/Anderson_PhysicsToday_2008.pdf

But tell us all again how you understand this better than physicists and
experienced sailors!

They may know what they are talking about but you don't, so they are
jargons. What does "lift" mean in the following quote: "Again, the net
lift force on the keel is due to the combination of that decreased
pressure on the high side and increased pressure on the other (low)
side."

LOL

Of course.


IS


--
Alan Baker
Vancouver, British Columbia

In article
,
taichiskiing wrote:

On Dec 26, 12:59 pm, Alan Baker wrote:
In article
,
taichiskiing wrote:
On Dec 24, 10:27 pm, Alan Baker wrote:
In article
,
taichiskiing wrote:
On Dec 24, 9:51 pm, Alan Baker wrote:
In article
,
Richard Henry wrote:
On Dec 24, 8:46 pm, taichiskiing

wrote:

http://pilotsweb.com/principle/forces.htm

Pilotsweb also has a page on Airfoils which includes brief
descriptions of Angle of Attack and Lift. It appears you have
not
read them.

To be accurate, that site's description of lift and angle of attack
has
diagrams that show lift with no deflection of the airflow.

i.e. completely wrong.

You two too can joint my slap your face challenge on Flatboarding:
the
flying style.

That didn't even remotely pass the intelligibility test.

You have failed the "slap your face challenge."

You consistently fail the *language* challenge.

Not really, given you consistently respond to my posts in a negative
way, you understand my language alright, so, it is either your denial,
or you've failed intelligently.

Nevertheless, you remain utterly wrong about keels and wings.

Your pathetic little knowledge gapper netkook's denial doesn't shed
the light.

"When you contradict Newton's Mechanism, you are wrong."

Tell that to Einstein.

Einstein did not contradict Newton's theories, he only extended the
field.


But I'm not contradicting Newton's *mechanics*, Chai-tea.

Not when you said the keel "points at an *angle* inward of the tangent
to the path of the boat." Actually, such a statement only reflects
that you know neither math nor physics.

Actually, it reflects reality.


For how Newton Second Law explains how a centripetal force turns an
object you need to study the portion titled "The forces during a
turn."

http://pilotsweb.com/principle/forces.htm

Since you've yet to address yourself to my references, why should I pay
the slightest attention to yours.



Page 48 and page 51 show and say it all.

http://books.google.com/books?id=kFj...PA51&dq=physic
s+of+sailing+keel+angle+of+attack&source=web&ots=q hVYqWYEDM&sig=DTw-W09hg
iFoTggqJQrUztP0MKI&hl=en&sa=X&oi=book_result&resnu m=2&ct=result#PPA52,M1

And this:

"A Keel is Needed - Without a keel, wind striking the sail would only
move the sailboat downwind. As with the sail, there will be an optimum
angle of attack for the keel as well."

http://sail-boats.suite101.com/article.cfm/how_sails_work

Note you ignored this; a quote that states explicitly that the keel has
an angle of attack.


The diagram shows it perfectly.

http://www.suite101.com/view_image.cfm/217685

And you ignored the diagram that shows that angle of attack.


And this:

A keel works only if the motion of the boat is not exactly in the
direction in which it¹s pointed. The boat must be moving somewhat
sideways. In that ³crabbing² motion, the keel moves through the water
with an angle of attack. Just as for the sails in the wind, that causes
the water on the ³high² (more downstream) side of the keel to move
faster and create a lower pressure. Again, the net lift force on the
keel is due to the combination of that decreased pressure on the high
side and increased pressure on the other (low) side."

http://web.mit.edu/preis/www/18.384/...sical_Applied_
Maths/Possible_Topics_files/Anderson_PhysicsToday_2008.pdf

But tell us all again how you understand this better than physicists and
experienced sailors!

They may know what they are talking about but you don't, so they are
jargons. What does "lift" mean in the following quote: "Again, the net
lift force on the keel is due to the combination of that decreased
pressure on the high side and increased pressure on the other (low)
side."

I do know what they're talking about. It is you that does not.

What part of that quote do you not understand? When the keel has an
angle of attack (i.e. at all times other than when the boat is heading
directly downwind), it has a high pressure side and a low pressure side.
Those pressure differences multiplied by the area of the keel give the
amount of lift the keel is generating.

--
Alan Baker
Vancouver, British Columbia
http://gallery.me.com/alangbaker/100008/DSCF0162/web.jpg

On Dec 28, 5:01 pm, Alan Baker wrote:
In article
,
taichiskiing wrote:

Not really, given you consistently respond to my posts in a negative
way, you understand my language alright, so, it is either your denial,
or you've failed intelligently.

"When you contradict Newton's Mechanism, you are wrong."

Tell that to Einstein.

Einstein did not contradict Newton's theories, he only extended the
field.

But I'm not contradicting Newton's *mechanics*, Chai-tea.

Not when you said the keel "points at an *angle* inward of the tangent
to the path of the boat." Actually, such a statement only reflects
that you know neither math nor physics.

Actually, it reflects reality.

The reality of "that you know neither math nor physics."

For how Newton Second Law explains how a centripetal force turns an
object you need to study the portion titled "The forces during a
turn."

http://pilotsweb.com/principle/forces.htm

Since you've yet to address yourself to my references, why should I pay
the slightest attention to yours.

Your argument has been disproved by Newton's Second Law.

Page 48 and page 51 show and say it all.

http://books.google.com/books?id=kFj...PA51&dq=physic
s+of+sailing+keel+angle+of+attack&source=web&ots=q hVYqWYEDM&sig=DTw-W09hg
iFoTggqJQrUztP0MKI&hl=en&sa=X&oi=book_result&resnu m=2&ct=result#PPA52,M1

And this:

"A Keel is Needed - Without a keel, wind striking the sail would only
move the sailboat downwind. As with the sail, there will be an optimum
angle of attack for the keel as well."

http://sail-boats.suite101.com/article.cfm/how_sails_work

Note you ignored this; a quote that states explicitly that the keel has
an angle of attack.

Jargon; the "angle of attack" in aerodynamic term is defined as the
angle formed by the relative wind and the chord line of the airfoil.
How's the "angle of attack" defined in sailing?

The diagram shows it perfectly.

http://www.suite101.com/view_image.cfm/217685

And you ignored the diagram that shows that angle of attack.

There's no "angle of attack" specified in that diagram.

And this:

A keel works only if the motion of the boat is not exactly in the
direction in which it¹s pointed. The boat must be moving somewhat
sideways. In that ³crabbing² motion, the keel moves through the water
with an angle of attack. Just as for the sails in the wind, that causes
the water on the ³high² (more downstream) side of the keel to move
faster and create a lower pressure. Again, the net lift force on the
keel is due to the combination of that decreased pressure on the high
side and increased pressure on the other (low) side."

http://web.mit.edu/preis/www/18.384/...sical_Applied_
Maths/Possible_Topics_files/Anderson_PhysicsToday_2008.pdf

But tell us all again how you understand this better than physicists and
experienced sailors!

They may know what they are talking about but you don't, so they are
jargons. What does "lift" mean in the following quote: "Again, the net
lift force on the keel is due to the combination of that decreased
pressure on the high side and increased pressure on the other (low)
side."

I do know what they're talking about. It is you that does not.

Yeah right,

What part of that quote do you not understand?

"What does 'lift' mean..."?

When the keel has an
angle of attack (i.e. at all times other than when the boat is heading
directly downwind), it has a high pressure side and a low pressure side.
Those pressure differences multiplied by the area of the keel give the
amount of lift the keel is generating.

Does this "lift" lift the hull out of water? And this question also
asked before, which side is high pressure and which side is low
pressure, in relation to the sailing path?


IS

--
Alan Baker
Vancouver, British Columbia

In article
,
taichiskiing wrote:

On Dec 28, 5:01 pm, Alan Baker wrote:
In article
,
taichiskiing wrote:

Not really, given you consistently respond to my posts in a negative
way, you understand my language alright, so, it is either your denial,
or you've failed intelligently.

"When you contradict Newton's Mechanism, you are wrong."

Tell that to Einstein.

Einstein did not contradict Newton's theories, he only extended the
field.

But I'm not contradicting Newton's *mechanics*, Chai-tea.

Not when you said the keel "points at an *angle* inward of the tangent
to the path of the boat." Actually, such a statement only reflects
that you know neither math nor physics.

Actually, it reflects reality.

The reality of "that you know neither math nor physics."

For how Newton Second Law explains how a centripetal force turns an
object you need to study the portion titled "The forces during a
turn."

http://pilotsweb.com/principle/forces.htm

Since you've yet to address yourself to my references, why should I pay
the slightest attention to yours.

Your argument has been disproved by Newton's Second Law.

Newton's second law merely states the relationship between force, mass
and acceleration, or more properly, it defines force as the derivative
of momentum with respect to time.

Now, please explain how that disproves my argument...


Page 48 and page 51 show and say it all.

http://books.google.com/books?id=kFj...=PA51&dq=physi
c
s+of+sailing+keel+angle+of+attack&source=web&ots=q hVYqWYEDM&sig=DTw-W09h
g
iFoTggqJQrUztP0MKI&hl=en&sa=X&oi=book_result&resnu m=2&ct=result#PPA52,M1


And this:

"A Keel is Needed - Without a keel, wind striking the sail would only
move the sailboat downwind. As with the sail, there will be an optimum
angle of attack for the keel as well."

http://sail-boats.suite101.com/article.cfm/how_sails_work

Note you ignored this; a quote that states explicitly that the keel has
an angle of attack.

Jargon; the "angle of attack" in aerodynamic term is defined as the
angle formed by the relative wind and the chord line of the airfoil.
How's the "angle of attack" defined in sailing?

In the case of a keel, it is the angle between the chord line of the
keel and the flow of water around it.


The diagram shows it perfectly.

http://www.suite101.com/view_image.cfm/217685

And you ignored the diagram that shows that angle of attack.

There's no "angle of attack" specified in that diagram.

It clearly shows the water flowing at an angle to the direction the keel
is pointing. That is the angle of attack.


And this:

A keel works only if the motion of the boat is not exactly in the
direction in which it¹s pointed. The boat must be moving somewhat
sideways. In that ³crabbing² motion, the keel moves through the water
with an angle of attack. Just as for the sails in the wind, that causes
the water on the ³high² (more downstream) side of the keel to move
faster and create a lower pressure. Again, the net lift force on the
keel is due to the combination of that decreased pressure on the high
side and increased pressure on the other (low) side."

http://web.mit.edu/preis/www/18.384/...ysical_Applied
_
Maths/Possible_Topics_files/Anderson_PhysicsToday_2008.pdf

But tell us all again how you understand this better than physicists
and
experienced sailors!

They may know what they are talking about but you don't, so they are
jargons. What does "lift" mean in the following quote: "Again, the net
lift force on the keel is due to the combination of that decreased
pressure on the high side and increased pressure on the other (low)
side."

I do know what they're talking about. It is you that does not.

Yeah right,

What part of that quote do you not understand?

"What does 'lift' mean..."?

That's not part of the quote. Try again.


When the keel has an
angle of attack (i.e. at all times other than when the boat is heading
directly downwind), it has a high pressure side and a low pressure side.
Those pressure differences multiplied by the area of the keel give the
amount of lift the keel is generating.

Does this "lift" lift the hull out of water? And this question also
asked before, which side is high pressure and which side is low
pressure, in relation to the sailing path?

Lift in fluid dynamics is defined as the component of the total force
exerted on an body by a fluid that is perpendicular to the direction of
the flow.

So in the case of a keel the lift is directed to the side, because a
keel is oriented at 90 degrees from a wing, which is the first object
for which the term lift was coined.

--
Alan Baker
Vancouver, British Columbia
http://gallery.me.com/alangbaker/100008/DSCF0162/web.jpg

In article
,
Alan Baker wrote:

Newton's second law merely states the relationship between force, mass
and acceleration, or more properly, it defines force as the derivative
of momentum with respect to time.

Now, please explain how that disproves my argument...

Hi Alan,

Quick question. Twice now you've said that lift = weight in a
descending plane. (at least that's what I thought you said)
Intuitively, it seems that lift weight in a descending plane, but I'm
not an engineer.

If you have time, would you explain that to me? If I've misunderstood
you, I apologize in advance.

Thanks,

Dave

In article

,
Dave Cartman wrote:

In article
,
Alan Baker wrote:

Newton's second law merely states the relationship between force, mass
and acceleration, or more properly, it defines force as the derivative
of momentum with respect to time.

Now, please explain how that disproves my argument...

Hi Alan,

Quick question. Twice now you've said that lift = weight in a
descending plane. (at least that's what I thought you said)
Intuitively, it seems that lift weight in a descending plane, but I'm
not an engineer.

If you have time, would you explain that to me? If I've misunderstood
you, I apologize in advance.

It's really quite simple.

Any time an object is moving at a constant velocity, all the forces on
it must be balanced.

If lift were less than weight, the aircraft wouldn't just be moving
downward, it would be *accelerating* downward.

--
Alan Baker
Vancouver, British Columbia
http://gallery.me.com/alangbaker/100008/DSCF0162/web.jpg

Alan Baker wrote:
In article

,
Dave Cartman wrote:

In article
,
Alan Baker wrote:

Newton's second law merely states the relationship between force, mass
and acceleration, or more properly, it defines force as the derivative
of momentum with respect to time.

Now, please explain how that disproves my argument...
Hi Alan,

Quick question. Twice now you've said that lift = weight in a
descending plane. (at least that's what I thought you said)
Intuitively, it seems that lift weight in a descending plane, but I'm
not an engineer.

If you have time, would you explain that to me? If I've misunderstood
you, I apologize in advance.

It's really quite simple.

Any time an object is moving at a constant velocity, all the forces on
it must be balanced.

If lift were less than weight, the aircraft wouldn't just be moving
downward, it would be *accelerating* downward.

Alan
My understanding is lift will increase or decrease depending on speed of
the fluid passing around the wing until you get the wing to stall by
passing the stall speed or getting too much angle of attack. If the
speed increases as the plane glides downward the lift goes up as the
downward forces increase. As long as no other variables change.
So if you angle pointed down a few degrees the speed will increase the
lift will go up until you stall then all bets are off.

Does this make sense to you?

In article ,
downhill wrote:

Alan Baker wrote:
In article

,
Dave Cartman wrote:

In article
,
Alan Baker wrote:

Newton's second law merely states the relationship between force, mass
and acceleration, or more properly, it defines force as the derivative
of momentum with respect to time.

Now, please explain how that disproves my argument...
Hi Alan,

Quick question. Twice now you've said that lift = weight in a
descending plane. (at least that's what I thought you said)
Intuitively, it seems that lift weight in a descending plane, but I'm
not an engineer.

If you have time, would you explain that to me? If I've misunderstood
you, I apologize in advance.

It's really quite simple.

Any time an object is moving at a constant velocity, all the forces on
it must be balanced.

If lift were less than weight, the aircraft wouldn't just be moving
downward, it would be *accelerating* downward.

Alan
My understanding is lift will increase or decrease depending on speed of
the fluid passing around the wing until you get the wing to stall by
passing the stall speed or getting too much angle of attack. If the
speed increases as the plane glides downward the lift goes up as the
downward forces increase. As long as no other variables change.
So if you angle pointed down a few degrees the speed will increase the
lift will go up until you stall then all bets are off.

Does this make sense to you?

It's not quite right, no.

Lift will increase with an increase in speed if angle of attack is held
constant, but if you do hold the AOA constant, the wing won't stall.
Stall is caused by an angle of attack to great for the air to follow the
curvature of the airfoil.

What you are envisioning is actually a two-part process: reduce power to
decrease speed, but pull back on the stick to get more lift from the
reduced power. Unfortunately, that only works up until a minimum speed
at which the airfoil can produce its maximum lift for that speed and
that maximum at that speed is equal to the aircraft's weight. Go any
slower, and you'll either start accelerating in the vertical axes, or if
you pull back even more, stall.

As for pushing forward and increasing speed, you have less AOA and thus
you have that factor acting to decrease lift countering the effect of
speed acting to increase it.

This is why laymen believe you use the stick to go up and down and the
throttle to go faster and slower, when in reality, the relationship is
more the other way around: use the stick to go faster or slower, and use
the throttle to climb or descend.

I understand the concepts pretty well, but if you want a site that
really explains them well, try he

http://www.av8n.com/how/

--
Alan Baker
Vancouver, British Columbia
http://gallery.me.com/alangbaker/100008/DSCF0162/web.jpg