Invention For Revolution In Transport Industry

"Sam Wormley" wrote in message
...
[snipped]
Excellent reply!

raz

In sci.physics, Edward Green

wrote
on 2 Aug 2003 23:18:39 -0700
:
The Ghost In The Machine wrote in message ...

In sci.physics, Abhi

wrote
on 2 Aug 2003 10:26:10 -0700
:

I am Abhijit Patil, 33 serving as an Assistant with LIC of India. I
have a Physics theory and based on this theory I believe, I have
invention, a basic device like wheel, which can revolutionize entire
transport industry on planet earth.

This invention is about keeping things stationary in air by a
mechanism so that these things do not fall on earth. This means, using
aerodynamics and propellants, we can build vehicles to go from one
place to another ...

So far, so good: as in, airplane, rocket, balloon, helicopter,
ultralight, air cushion vehicle, and all other variants on flying
machines!

Question is, why do you believe you have thought of some revolutionary
method for keeping stuff airborne, never before known to man? All
methods rely on differential air pressure, most further rely on
reactive forces with moving air: the field is well explored.

ghost in reply recovers result that name of game in low power flight
is to move as much air as slowly as possible

If we move 10 kg of air per second downward at .981 m/s
using a wider fan, we can reduce that power expenditure
to 4.811805 W.

I suspect 5W is well below a turning point where we have begun burning
more power in friction than in reactive thrust.

And has anyone ever spoken to you about significant digits? ;-)

Not significantly. :-)

But you're right; I could be a little more consistent at it.


... Gossamer Albatross ...

The general shape of which, as well as the bird it's name after, makes
the point about moving a lot of air slowly ... big wings, slow plane,
low power.

That is if one wants to use as little power as possible -- which is
not always the objective. For example, fighter planes which
skimp on the power will probably get shot down... :-)


The problem with this approach, as well as eventual dominance of
friction, is incompatibility with personal transport: even if modern
material permitted it, it doesn't exactly solve tranportation problems
in congested areas for everybody to unfold their 30m wingspan
ultralight and sail away on a song.

True.


(Ideally, the air would be taken from the sides of the car,
not the top, and directed downward through 90 angle tubes.
The reasons for this should be fairly obvious; the moving
air will exert a downward pressure on the car.

I'm not sure it's obvious, or even correct! Aerodynamic lift is one of
those things it's possible to make about ten passes at, feel you've
learned something every time, and _really_ have a handle on it this
time ... and then find yourself without a clear grok of some simple
sounding issue, like the one you just propose. Lift is not something
we are well pre-programed to intuit -- presumably because we are not
birds.

There is that. I'll admit it gets weird at times, but one pass
that may result in unexpected results is that the inrush of
air going down is accelerated *before* the fans, but some of it
deflects off, reducing the pressure on top. The pressure at the
bottom increases since we're pushing air that way, and we may
get a little more lift than intended -- especially if the car is
near enough to the ground to allow the downwward air to bounce
back up, increasing pressure still more.

To do it fully right would require some sort of finite element
simulator which among other things understands fluid flow.

I'll have to find one... :-)


A cunningly-employed kg of gasoline would
generate 45 MJ and might keep me up there for a day, given a
big enough and light enough fan that can move 1 metric tonne
of air a second at 1 m/s or so.

At least several hours anyway -- I'm picturing an ultra-light powered
glider with a small motor.

That would work reasonably well, yes. :-)

--
#191,
It's still legal to go .sigless.

Didn't the Yippies try this with the Pentagon in the sixties? Like, they
tried to levitate it? Don't know if they were particularly successful.

The Ghost In The Machine wrote in message ...
....

... Gossamer Albatross ...

The general shape of which, as well as the bird it's name after, makes
the point about moving a lot of air slowly ... big wings, slow plane,
low power.

That is if one wants to use as little power as possible -- which is
not always the objective. For example, fighter planes which
skimp on the power will probably get shot down... :-)

Yes, certainly. I assumed we were both considering the problem of
flying with as little power as possible, to start a revolution in
transport industry: that was before I realized the proposed invention
was to fly with _no_ power, and I don't mean ballooning, either.

....

(Ideally, the air would be taken from the sides of the car,
not the top, and directed downward through 90 angle tubes.
The reasons for this should be fairly obvious; the moving
air will exert a downward pressure on the car.

I'm not sure it's obvious, or even correct! Aerodynamic lift is one of
those things it's possible to make about ten passes at, feel you've
learned something every time, and _really_ have a handle on it this
time ... and then find yourself without a clear grok of some simple
sounding issue, like the one you just propose. Lift is not something
we are well pre-programed to intuit -- presumably because we are not
birds.

There is that. I'll admit it gets weird at times, but one pass
that may result in unexpected results is that the inrush of
air going down is accelerated *before* the fans, but some of it
deflects off, reducing the pressure on top. The pressure at the
bottom increases since we're pushing air that way, and we may
get a little more lift than intended -- especially if the car is
near enough to the ground to allow the downwward air to bounce
back up, increasing pressure still more.

The last thing you are talking of is called "ground effect". The rest
of your oracle is hard to interpret. :-)

A closely related question I _have_ contemplated is the feasibility of
a "suck hoverer". A suck-hoverer is a hypothetical machine which
achieves lift solely by reducing over-pressure, but does not
accelerate a plume of air beneath it, nor increase under-pressure
(geometric sense of "under" and "over" here).

Off the cuff, the smarty pants answer is "conservation of momentum
says no". The answer is correct, but IMHO, the given reason
insufficient. I liked that. I am a Dionysian, like Lester Zick ... I
just like to think I'm usually a _correct_ Dionysian. ;-)

In sci.physics, Edward Green

wrote
on 3 Aug 2003 17:56:29 -0700
:
The Ghost In The Machine wrote in message ...
...

... Gossamer Albatross ...

The general shape of which, as well as the bird it's name after, makes
the point about moving a lot of air slowly ... big wings, slow plane,
low power.

That is if one wants to use as little power as possible -- which is
not always the objective. For example, fighter planes which
skimp on the power will probably get shot down... :-)

Yes, certainly. I assumed we were both considering the problem of
flying with as little power as possible, to start a revolution in
transport industry: that was before I realized the proposed invention
was to fly with _no_ power, and I don't mean ballooning, either.

Yeah, well, ballooning is about the only way one can fly with
no power. I'm not even sure electrostatics would work,
mostly because if one throws a charged item into the air
(say it has a negative charge) the negative charges in the
Earth are repulsed, leaving what is essentially a positive
charge. If one reverses the polarity the Earth's negative
charges are attracted. Either way, the downward force
appears to increase.

At least with ballooning (assuming a lighter-than-air gas such
as helium) one can compensate for the gravity without using
energy.


...

(Ideally, the air would be taken from the sides of the car,
not the top, and directed downward through 90 angle tubes.
The reasons for this should be fairly obvious; the moving
air will exert a downward pressure on the car.

I'm not sure it's obvious, or even correct! Aerodynamic lift is one of
those things it's possible to make about ten passes at, feel you've
learned something every time, and _really_ have a handle on it this
time ... and then find yourself without a clear grok of some simple
sounding issue, like the one you just propose. Lift is not something
we are well pre-programed to intuit -- presumably because we are not
birds.

There is that. I'll admit it gets weird at times, but one pass
that may result in unexpected results is that the inrush of
air going down is accelerated *before* the fans, but some of it
deflects off, reducing the pressure on top. The pressure at the
bottom increases since we're pushing air that way, and we may
get a little more lift than intended -- especially if the car is
near enough to the ground to allow the downwward air to bounce
back up, increasing pressure still more.

The last thing you are talking of is called "ground effect". The rest
of your oracle is hard to interpret. :-)

Hmm...my verbiage does seem to be a bit on the confusing side,
upon rereading. The idea was generally that the fans on a
hypothetical "flying square" are dragging air from the top; this
air, together with other air, will probably blow over the top
of the "flying square", pushing it down. Or maybe not; I don't
know offhand. Of course the air accelerated through the fan
allows the "flying square" to stay up, as the air is given
enough momentum to compensate for the "flying square"'s apparent
violation of gravity. Otherwise the item would simply fall
4.905 m in 1 second to the ground (the value was to make the
power computations relatively simple).


A closely related question I _have_ contemplated is the feasibility of
a "suck hoverer". A suck-hoverer is a hypothetical machine which
achieves lift solely by reducing over-pressure, but does not
accelerate a plume of air beneath it, nor increase under-pressure
(geometric sense of "under" and "over" here).

There is/was NASA (?) research on poking holes in an
airplane wing and connecting them to a pump, to improve
its characteristics. Unfortunately I forget the precise
details. This looks like a variant of suck-hovering,
although it doesn't appear to completely lift the wing,
just get rid of some of the less desirable characteristics
thereof. (Whatever they are. :-) )


Off the cuff, the smarty pants answer is "conservation of momentum
says no". The answer is correct, but IMHO, the given reason
insufficient. I liked that. I am a Dionysian, like Lester Zick ... I
just like to think I'm usually a _correct_ Dionysian. ;-)

The main problem with reducing pressure is that Nature,
at least in atmosphere, abhors a vacuum.... :-)

--
#191,
It's still legal to go .sigless.

"Abhi" wrote in message
m...
Now the following message is being sent to people related to
manufacturer in transport industry like Atlas, Hercules, Hero etc. The
world will never be the same again....

Dear Sir,

I am Abhijit Patil, 33 serving as an Assistant with LIC of India. I
have a Physics theory and based on this theory I believe, I have
invention, a basic device like wheel, which can revolutionize entire
transport industry on planet earth.


Well, if nothing else, I'm sure the E-mail screeners at Altlas,
Hercules, Hero, etc. will welcome the slight variation on the
"Nigerian business opportunity" messages that occupy the majority
of their time.

-Eric

Abhi wrote:

Now the following message is being sent to people related to
manufacturer in transport industry like Atlas, Hercules, Hero etc. The
world will never be the same again....

Dear Sir,

I am Abhijit Patil, 33 serving as an Assistant with LIC of India. I
have a Physics theory and based on this theory I believe, I have
invention, a basic device like wheel, which can revolutionize entire
transport industry on planet earth.

This invention is about keeping things stationary in air by a
mechanism so that these things do not fall on earth. This means, using
aerodynamics and propellants, we can build vehicles to go from one
place to another faster and cheaper which ordinary man can afford.

I think that Wilbur and Orville beat you to it by about 100 years.

John Anderson