visualisation of the lift distribution over a wing

In article ,
Beryl wrote:

Alan Baker wrote:
In article ,
Beryl wrote:

Alan Baker wrote:
In article ,
Jim Logajan wrote:

Alan Baker wrote:
If there is no downwash, it will not fly. No.
You are arguing a point not under contention (at least with respect to
heavier-than-air aircraft.)

See everyone: this is why understanding of the actual facts is
required.
The ground isn't required. Air has inertia, and it's just as much a part
of the earth as dirt and rocks are. So why are you fixated on the
earth's solid surface? It compresses too, you know. You could argue that
the downforce travels through the whole planet and back into the
atmosphere in China.

You simply haven't really read anyone else's posts to understand what
they
are stating.
The previous poster just said:

"Let's talk about helicopters. We can replace that rotor with a squirrel
cage fan. Air is drawn down into the fan as before, and most of the
pressure differential is due to lowering pressure above the fan. As
before... except that now the air is exhausted out the periphery of the
centrifugal-flow squirrel cage fan, not down as it was with the old
axial-flow rotor. Will it fly? Where's the downwash?"

She ("Beryl"?)
A mineral

is clearly implying that such an hypothetical craft could remain airborne
without downwash.
No, I only asked.

How else can it be read?
Read it as a question.

So what is your answer? Can the postulated craft fly if there is no
downdraft?

The inflow strikes the underside of the conventional rotor disk, but
strikes the topside of the centrifugal fan disk. That's all!

I'm betting you'll find a way to avoid answering...

I did.


No surprise there.

So where are we? Your downward accelerated air might continue traveling
until it's stopped by the earth's surface, which is the only thing that
can stop it. But it isn't simply thrown down. Much of the finite energy
put into to the air is "wasted" in spinning it. Kinetic energy becomes heat.

And now you're just ducking.

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

Alan Baker wrote:
In article ,
Beryl wrote:

Alan Baker wrote:
In article ,
Beryl wrote:

Alan Baker wrote:
In article ,
Jim Logajan wrote:

Alan Baker wrote:
If there is no downwash, it will not fly. No.
You are arguing a point not under contention (at least with respect to
heavier-than-air aircraft.)

See everyone: this is why understanding of the actual facts is
required.
The ground isn't required. Air has inertia, and it's just as much a part
of the earth as dirt and rocks are. So why are you fixated on the
earth's solid surface? It compresses too, you know. You could argue that
the downforce travels through the whole planet and back into the
atmosphere in China.

You simply haven't really read anyone else's posts to understand what
they
are stating.
The previous poster just said:

"Let's talk about helicopters. We can replace that rotor with a squirrel
cage fan. Air is drawn down into the fan as before, and most of the
pressure differential is due to lowering pressure above the fan. As
before... except that now the air is exhausted out the periphery of the
centrifugal-flow squirrel cage fan, not down as it was with the old
axial-flow rotor. Will it fly? Where's the downwash?"

She ("Beryl"?)
A mineral

is clearly implying that such an hypothetical craft could remain airborne
without downwash.
No, I only asked.

How else can it be read?
Read it as a question.
So what is your answer? Can the postulated craft fly if there is no
downdraft?
The inflow strikes the underside of the conventional rotor disk, but
strikes the topside of the centrifugal fan disk. That's all!

I'm betting you'll find a way to avoid answering...
I did.


No surprise there.

So where are we? Your downward accelerated air might continue traveling
until it's stopped by the earth's surface, which is the only thing that
can stop it. But it isn't simply thrown down. Much of the finite energy
put into to the air is "wasted" in spinning it. Kinetic energy becomes heat.

And now you're just ducking.

Like you do, every time it's pointed out that when air is pushed down,
an equal volume of air must go UP? You then avoid saying "air flow" and
start grasping for other terms.

So how far down do you think air can flow before the ground is out of
reach? Forever?

In article ,
Beryl wrote:

Alan Baker wrote:
In article ,
Beryl wrote:

Alan Baker wrote:
In article ,
Beryl wrote:

Alan Baker wrote:
In article ,
Jim Logajan wrote:

Alan Baker wrote:
If there is no downwash, it will not fly. No.
You are arguing a point not under contention (at least with respect to
heavier-than-air aircraft.)

See everyone: this is why understanding of the actual facts is
required.
The ground isn't required. Air has inertia, and it's just as much a part
of the earth as dirt and rocks are. So why are you fixated on the
earth's solid surface? It compresses too, you know. You could argue that
the downforce travels through the whole planet and back into the
atmosphere in China.

You simply haven't really read anyone else's posts to understand what
they
are stating.
The previous poster just said:

"Let's talk about helicopters. We can replace that rotor with a
squirrel
cage fan. Air is drawn down into the fan as before, and most of the
pressure differential is due to lowering pressure above the fan. As
before... except that now the air is exhausted out the periphery of the
centrifugal-flow squirrel cage fan, not down as it was with the old
axial-flow rotor. Will it fly? Where's the downwash?"

She ("Beryl"?)
A mineral

is clearly implying that such an hypothetical craft could remain
airborne
without downwash.
No, I only asked.

How else can it be read?
Read it as a question.
So what is your answer? Can the postulated craft fly if there is no
downdraft?
The inflow strikes the underside of the conventional rotor disk, but
strikes the topside of the centrifugal fan disk. That's all!

I'm betting you'll find a way to avoid answering...
I did.


No surprise there.

So where are we? Your downward accelerated air might continue traveling
until it's stopped by the earth's surface, which is the only thing that
can stop it. But it isn't simply thrown down. Much of the finite energy
put into to the air is "wasted" in spinning it. Kinetic energy becomes
heat.

And now you're just ducking.

Like you do, every time it's pointed out that when air is pushed down,
an equal volume of air must go UP? You then avoid saying "air flow" and
start grasping for other terms.

Eventually it must go up. After it has transferred its momentum to the
earth.

I'm sorry, but that is the reality of the situation.


So how far down do you think air can flow before the ground is out of
reach? Forever?

Essentially, yes. The fact is that if the aircraft and the Earth are to
remain the same distance apart, the plane must "push" against the Earth
with a force equal to the force of gravity. The air is the medium by
which the aircraft can transmit that push.

And to explain to you why your hypothetical craft with the radial
exhaust of air from a centrifugal fan won't work. The air that enters
downward gets turned to go sideways. That 90 degree turn can only be
accomplished by the a push upward from the aircraft and thus the air
must push down on the system with an equal but opposite force.

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

Alan Baker wrote:
In article ,
Beryl wrote:

Alan Baker wrote:
In article ,
Beryl wrote:

Alan Baker wrote:
In article ,
Beryl wrote:

Alan Baker wrote:
In article ,
Jim Logajan wrote:

Alan Baker wrote:
If there is no downwash, it will not fly. No.
You are arguing a point not under contention (at least with respect to
heavier-than-air aircraft.)

See everyone: this is why understanding of the actual facts is
required.
The ground isn't required. Air has inertia, and it's just as much a part
of the earth as dirt and rocks are. So why are you fixated on the
earth's solid surface? It compresses too, you know. You could argue that
the downforce travels through the whole planet and back into the
atmosphere in China.

You simply haven't really read anyone else's posts to understand what
they
are stating.
The previous poster just said:

"Let's talk about helicopters. We can replace that rotor with a
squirrel
cage fan. Air is drawn down into the fan as before, and most of the
pressure differential is due to lowering pressure above the fan. As
before... except that now the air is exhausted out the periphery of the
centrifugal-flow squirrel cage fan, not down as it was with the old
axial-flow rotor. Will it fly? Where's the downwash?"

She ("Beryl"?)
A mineral

is clearly implying that such an hypothetical craft could remain
airborne
without downwash.
No, I only asked.

How else can it be read?
Read it as a question.
So what is your answer? Can the postulated craft fly if there is no
downdraft?
The inflow strikes the underside of the conventional rotor disk, but
strikes the topside of the centrifugal fan disk. That's all!

I'm betting you'll find a way to avoid answering...
I did.

No surprise there.

So where are we? Your downward accelerated air might continue traveling
until it's stopped by the earth's surface, which is the only thing that
can stop it. But it isn't simply thrown down. Much of the finite energy
put into to the air is "wasted" in spinning it. Kinetic energy becomes
heat.
And now you're just ducking.
Like you do, every time it's pointed out that when air is pushed down,
an equal volume of air must go UP? You then avoid saying "air flow" and
start grasping for other terms.

Eventually it must go up. After it has transferred its momentum to the
earth.

You've seen pics of it curling right back up.
http://www.efluids.com/efluids/gallery/gallery_pages/Morris_4.jsp
It hasn't bounced off the ground.

I'm sorry, but that is the reality of the situation.

Pressure waves can reach the ground, without the air in the column
descending to the ground.

So how far down do you think air can flow before the ground is out of
reach? Forever?

Essentially, yes.

How? A wing doesn't keep pushing down on a parcel of air forever. It
gives that air a shove, then it moves on. That downward-shoved air
pushes the air below it out of the way, not just down, but sideways.
Then the sideways-moving air shoves its neighboring air out of the way,
not just sideways, but down and up. Add all the "downs" and subtract all
the "ups" until there's nothing left.

The fact is that if the aircraft and the Earth are to remain the same distance apart, the plane must "push" against the Earth
with a force equal to the force of gravity. The air is the medium by
which the aircraft can transmit that push.

Right. And I can push against the hill across the road with my voice.
Not much, but enough to move the diaphragm in a microphone over there,
in a split second. The air expelled from lungs is never going to make it
across the road.

And to explain to you why your hypothetical craft with the radial
exhaust of air from a centrifugal fan won't work. The air that enters
downward gets turned to go sideways. That 90 degree turn can only be
accomplished by the a push upward from the aircraft and thus the air
must push down on the system with an equal but opposite force.

But is that 90 degree turn *exactly* the same as a 180 degree turn that
directs incoming air back in the opposite direction? No, so I'll just
turn my squirrel cage upside down with 180 degree flow redirection, and
get lift with no net downwash.

In article ,
Beryl wrote:

Alan Baker wrote:
In article ,
Beryl wrote:

Alan Baker wrote:
In article ,
Beryl wrote:

Alan Baker wrote:
In article ,
Beryl wrote:

Alan Baker wrote:
In article ,
Jim Logajan wrote:

Alan Baker wrote:
If there is no downwash, it will not fly. No.
You are arguing a point not under contention (at least with respect
to
heavier-than-air aircraft.)

See everyone: this is why understanding of the actual facts is
required.
The ground isn't required. Air has inertia, and it's just as much a
part
of the earth as dirt and rocks are. So why are you fixated on the
earth's solid surface? It compresses too, you know. You could argue
that
the downforce travels through the whole planet and back into the
atmosphere in China.

You simply haven't really read anyone else's posts to understand
what
they
are stating.
The previous poster just said:

"Let's talk about helicopters. We can replace that rotor with a
squirrel
cage fan. Air is drawn down into the fan as before, and most of the
pressure differential is due to lowering pressure above the fan. As
before... except that now the air is exhausted out the periphery of
the
centrifugal-flow squirrel cage fan, not down as it was with the old
axial-flow rotor. Will it fly? Where's the downwash?"

She ("Beryl"?)
A mineral

is clearly implying that such an hypothetical craft could remain
airborne
without downwash.
No, I only asked.

How else can it be read?
Read it as a question.
So what is your answer? Can the postulated craft fly if there is no
downdraft?
The inflow strikes the underside of the conventional rotor disk, but
strikes the topside of the centrifugal fan disk. That's all!

I'm betting you'll find a way to avoid answering...
I did.

No surprise there.

So where are we? Your downward accelerated air might continue traveling
until it's stopped by the earth's surface, which is the only thing that
can stop it. But it isn't simply thrown down. Much of the finite energy
put into to the air is "wasted" in spinning it. Kinetic energy becomes
heat.
And now you're just ducking.
Like you do, every time it's pointed out that when air is pushed down,
an equal volume of air must go UP? You then avoid saying "air flow" and
start grasping for other terms.

Eventually it must go up. After it has transferred its momentum to the
earth.

You've seen pics of it curling right back up.
http://www.efluids.com/efluids/gallery/gallery_pages/Morris_4.jsp
It hasn't bounced off the ground.

You've seen the edges curling back up. For anything with downward
momentum to start moving upward, something else has to start moving
downward.

Have you heard of "Conservation of Momentum"?


I'm sorry, but that is the reality of the situation.

Pressure waves can reach the ground, without the air in the column
descending to the ground.

I never said that the particular molecules that the aircraft touches are
the ones that have to reach the ground.


So how far down do you think air can flow before the ground is out of
reach? Forever?

Essentially, yes.

How? A wing doesn't keep pushing down on a parcel of air forever. It
gives that air a shove, then it moves on. That downward-shoved air
pushes the air below it out of the way, not just down, but sideways.
Then the sideways-moving air shoves its neighboring air out of the way,
not just sideways, but down and up. Add all the "downs" and subtract all
the "ups" until there's nothing left.

Look up "Conservation of Momentum" and get back to me.


The fact is that if the aircraft and the Earth are to remain the same
distance apart, the plane must "push" against the Earth
with a force equal to the force of gravity. The air is the medium by
which the aircraft can transmit that push.

Right. And I can push against the hill across the road with my voice.
Not much, but enough to move the diaphragm in a microphone over there,
in a split second. The air expelled from lungs is never going to make it
across the road.

No, sorry. You don't push the hill with your voice. The pressure waves
contain both positive and negative phases.


And to explain to you why your hypothetical craft with the radial
exhaust of air from a centrifugal fan won't work. The air that enters
downward gets turned to go sideways. That 90 degree turn can only be
accomplished by the a push upward from the aircraft and thus the air
must push down on the system with an equal but opposite force.

But is that 90 degree turn *exactly* the same as a 180 degree turn that
directs incoming air back in the opposite direction? No, so I'll just
turn my squirrel cage upside down with 180 degree flow redirection, and
get lift with no net downwash.

No, you won't.

No downwash, no lift. No go learn something.

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

Alan Baker wrote:
In article , Beryl
wrote:
...

You've seen pics of it curling right back up.
http://www.efluids.com/efluids/gallery/gallery_pages/Morris_4.jsp
It hasn't bounced off the ground.

You've seen the edges curling back up.

That photo shows ALL of the flow curling back up. The bottom of the
vortex couldn't be any clearer, and there's nothing extending further
down underneath it.

Pressure waves can reach the ground, without the air in the column
descending to the ground.

I never said that the particular molecules that the aircraft touches
are the ones that have to reach the ground.

You said "The net flow is downward until it hits the ground and the
momentum is transfer to the earth."

The molecules that "reach" the ground are the ones that
were *already there* at ground level.

The fact is that if the aircraft and the Earth are to remain the
same distance apart, the plane must "push" against the Earth
with a force equal to the force of gravity. The air is the medium
by which the aircraft can transmit that push.

Right. And I can push against the hill across the road with my
voice. Not much, but enough to move the diaphragm in a microphone
over there, in a split second. The air expelled from lungs is never
going to make it across the road.

No, sorry. You don't push the hill with your voice.

Of course I do.

The pressure waves contain both positive and negative phases.

So you think that a positive won't push because a negative will be
coming along shortly?

And to explain to you why your hypothetical craft with the radial
exhaust of air from a centrifugal fan won't work. The air that
enters downward gets turned to go sideways. That 90 degree turn
can only be accomplished by the a push upward from the aircraft
and thus the air must push down on the system with an equal but
opposite force.
But is that 90 degree turn *exactly* the same as a 180 degree turn
that directs incoming air back in the opposite direction? No, so
I'll just turn my squirrel cage upside down with 180 degree flow
redirection, and get lift with no net downwash.

No, you won't.

No downwash, no lift. No go learn something.

Let's learn here. From you. Is that 90 degree turn *exactly* the same as
a 180 degree turn that directs incoming air back in the opposite direction?

In article ,
Beryl wrote:

Alan Baker wrote:
In article , Beryl
wrote:
...

You've seen pics of it curling right back up.
http://www.efluids.com/efluids/gallery/gallery_pages/Morris_4.jsp
It hasn't bounced off the ground.

You've seen the edges curling back up.

That photo shows ALL of the flow curling back up. The bottom of the
vortex couldn't be any clearer, and there's nothing extending further
down underneath it.

Sorry, but you're wrong.

First of all, the downward motion of the vortex clearly carries right
out the bottom of the frame. Second, I've stated all along that as time
passes the momentum is diffused among more and more air.



Pressure waves can reach the ground, without the air in the column
descending to the ground.

I never said that the particular molecules that the aircraft touches
are the ones that have to reach the ground.

You said "The net flow is downward until it hits the ground and the
momentum is transfer to the earth."

And it is: the *net* flow.


The molecules that "reach" the ground are the ones that
were *already there* at ground level.

I never implied that the same molecules are the ones that eventually
strike the ground.


The fact is that if the aircraft and the Earth are to remain the
same distance apart, the plane must "push" against the Earth
with a force equal to the force of gravity. The air is the medium
by which the aircraft can transmit that push.

Right. And I can push against the hill across the road with my
voice. Not much, but enough to move the diaphragm in a microphone
over there, in a split second. The air expelled from lungs is never
going to make it across the road.

No, sorry. You don't push the hill with your voice.

Of course I do.

The pressure waves contain both positive and negative phases.

So you think that a positive won't push because a negative will be
coming along shortly?

I think their will be no net push, yes.

See the difference: sound waves, no net flow: no net push.


And to explain to you why your hypothetical craft with the radial
exhaust of air from a centrifugal fan won't work. The air that
enters downward gets turned to go sideways. That 90 degree turn
can only be accomplished by the a push upward from the aircraft
and thus the air must push down on the system with an equal but
opposite force.
But is that 90 degree turn *exactly* the same as a 180 degree turn
that directs incoming air back in the opposite direction? No, so
I'll just turn my squirrel cage upside down with 180 degree flow
redirection, and get lift with no net downwash.

No, you won't.

No downwash, no lift. No go learn something.

Let's learn here. From you. Is that 90 degree turn *exactly* the same as
a 180 degree turn that directs incoming air back in the opposite direction?

Read this:

"To determine [the angle represented by a greek letter in the original
text], we observe that no downwash is generated when the wing generates
no lift."

http://www.aoe.vt.edu/~cwoolsey/Cour...al/Aerodynamic
Properties.pdf

Read it over and over again until you get it.

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

"Alan Baker" wrote

Look up "Conservation of Momentum" and get back to me.

I've been polite as long as I can stand it.

HEY DUMBASS ! Get out of the textbook, and into the real world.

You completely ignore the real world effects of friction. That is a hint,
to where the momentum eventually goes to.

You push a car on perfectly level ground. It does not roll forever. What
happened to conservation of momentum?

Same thing with your stupid downflow hits the earth argument. Friction
kills that wave off in relatively short order, dumbass. Get real.

Group, I am sorry for my tone, and for biting on this not too smart troll.
I'll be good now.
--
Jim in NC

In article ,
"Morgans" wrote:

"Alan Baker" wrote

Look up "Conservation of Momentum" and get back to me.

I've been polite as long as I can stand it.

HEY DUMBASS ! Get out of the textbook, and into the real world.

You completely ignore the real world effects of friction. That is a hint,
to where the momentum eventually goes to.

No. That's not where momentum eventually goes to.


You push a car on perfectly level ground. It does not roll forever. What
happened to conservation of momentum?

It's momentum is transferred to the ground and air by friction.

But momentum is conserved.


Same thing with your stupid downflow hits the earth argument. Friction
kills that wave off in relatively short order, dumbass. Get real.

Nope. Friction just spreads it around.


Group, I am sorry for my tone, and for biting on this not too smart troll.
I'll be good now.

You'll be wrong, though.

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