Long cables to power "ioncraft" to orbit?

[Jim Logajan]

If Rummy really said this, then he is much more widely read than I
would have believed. This is a variation of a quotation from Lady
Burton, attributed as an 'Arabian Proverb':
"Men are four:
He who knows not and knows not he knows not, he is a fool--shun him;
He who knows not and knows he knows not, he is simple--teach him;
He who knows and knows not he knows, he is asleep--wake him;
He who knows and knows he knows, he is wise--follow him!"

He who knows what just ain't so, he works in government--to hell with him!

 

[George Dishman]

The point of this thread is the savings in power you would
get by using a lifter thruster method.
Look at the table near the bottom on this page:

Lifter Theory.
http://jnaudin.free.fr/html/lf­theory.htm

The last line in this table labled Thrust(g)/Power(W) ratio gives the
weight that could be lifted for given power with the air density
available at ground level. It is given as 0.509, or about 2 to 1 for
power in watts required to lift a weight in grams.
This is at ground level.

This is also at zero speed. Energy is force times
distance and power is force times speed so 0.5g
rising vertically at 202 m/s would double the power
needed. You seem to be neglecting that, but at
orbital speeds it is going to be far greater than
the figures you are quoting.

This is the same problem you had with the thrust
equations, you are forgetting the basic conservation
laws for momentum and energy.

On a practical front, it is trivial to reach high
altitude, just launch from a balloon, they need no
power at all. The hard part is reaching orbital
velocity once you get up there, and lifters aren't
going to work well in a near vacuum.

the only benefit they give you is the reaction mass
of the surrounding air at low altitude but this
advantage will soon be outweighed by the inefficiency
of burning fuel to run a generator which in turn
powers the lifter as the air gets thinner.

George

 

[bz]

That is the least of his problems. AC to high-VDC conversion is
not trivial, but it can be done. Getting ~3000 watts is slightly
more difficult. Getting flexible, light, cabling that can
deliver it at great length? Priceless...

His problems start with his belief that "lift" equates to
"overcoming air friction due to velocity through the very medium
being used to produce lift".

And the USAF charged the skin of an aircraft for the purpose of
being stealthy. No improvement in flight characterisitics was
noted. So I suspect that if we aren't talking MHD, then we are
talking about repelling the lifting body with the Earth as one
"capacitive plate". Anything else is window dressing, mere
slight-of-hand to distract the unwary.

The effect is apparently due to 'ion wind' induced in the air by 30kv on a
set of emission points spaced some distance above a grid of wires.

Electrons emitted by the points ionize the air. The negative ions are then
attracted to the positive grid, producing lift.

The article referenced earlier in the thread explains it better than I can.


--
bz

please pardon my infinite ignorance, the set-of-things-I-do-not-know is an
infinite set.

[email protected] remove ch100-5 to avoid spam trap

 

[Robert Clark]

...
His problems start with his belief that "lift" equates to
"overcoming air friction due to velocity through the very medium
being used to produce lift".

And the USAF charged the skin of an aircraft for the purpose of
being stealthy. No improvement in flight characterisitics was
noted. So I suspect that if we aren't talking MHD, then we are
talking about repelling the lifting body with the Earth as one
"capacitive plate". Anything else is window dressing, mere
slight-of-hand to distract the unwary.

David A. Smith

Leik Myrabo et.al. are investigating this type of "ionized air" drive
as a supplement to their beamed laser propulsion method:

6-GHz Microwave Power-Beaming Demonstration with 6-kV Rectenna and
Ion-Breeze Thruster.
T. Cummings,* J. Janssen,* J. Karnesky,* D. Laks,* M. Santillo,* B.
Strause,* L. N. Myrabo,* A. Alden,¶ P. Bouliane,¶ and M. Zhang¶
*Department of Mechanical, Aerospace and Nuclear Engineering,
RensselaerPolytechnic Institute, Troy, New York 12180
¶Communications Research Centre, Ottawa, Ontario, Canada
"On 14 April 2003 at the Communications Research Center (CRC) in
Ottawa, Ontario, a 5.85-GHz transmitter beamed 3-kW of microwave power
to a remote rectifying antenna (i.e., rectenna) that delivered 6-kV to
a special `Ion-Breeze' Engine (IBE). Three of CRC's 26.5-cm by 31-cm
rectennas were connected in series to provide the ~6-kV output. RPI's
low-voltage IBE thrusters performed well in a "world's first"
power-beaming demonstration with rectennas and endoatmospheric
ion-propulsion engines. The successful tests were a low-tech,
proof-of-concept demonstration for the future full-sized MicroWave
Lightcraft (MWLC) and its air breathing `loiter' propulsion mode.
Additional IBE experiments investigated the feasibility of producing
flight control forces on the MWLC. The objective was to torque the
charged hull for `pitch' or `roll' maneuvers. The torquing
demonstration was entirely successful."
http://proceedings.aip.org/getabs/s...prog=normal&id=APCPCS000702000001000430000001

Experimental investigation of 2-D ion mobility endoatmospheric drive
(IMED).
U. Filiba, L. N. Myrabo, and H. T. Nagamatsu (Rensselaer Polytechnic
Inst., Troy, NY)
AIAA-2001-3667
AIAA/ASME/SAE/ASEE Joint Propulsion Conference and Exhibit, 37th, Salt
Lake City, UT, July 8-11, 2001
http://www.aiaa.org/content.cfm?pageid=406&gTable=mtgpaper&gID=21851


The "endoatmospheric ion-propulsion" engine is clearly the same thing
as the lifter drive.


Bob Clark

 

[Robert Clark]

This is also at zero speed. Energy is force times
distance and power is force times speed so 0.5g
rising vertically at 202 m/s would double the power
needed. You seem to be neglecting that, but at
orbital speeds it is going to be far greater than
the figures you are quoting.

This is the same problem you had with the thrust
equations, you are forgetting the basic conservation
laws for momentum and energy.

On a practical front, it is trivial to reach high
altitude, just launch from a balloon, they need no
power at all. The hard part is reaching orbital
velocity once you get up there, and lifters aren't
going to work well in a near vacuum.

the only benefit they give you is the reaction mass
of the surrounding air at low altitude but this
advantage will soon be outweighed by the inefficiency
of burning fuel to run a generator which in turn
powers the lifter as the air gets thinner.

George

If you look at the pages describing the drive, the electrical power is
a means to create airflow. The thrust is due to this airflow. I'm
calculating the thrust as you do with the rocket equation.
What would be dependent on the speed is the drag. That would be a
rather complicated dependence on the shape of the vehicle. As a first
guess you could give the craft the aerodynmic shape of a supersonic or
hypersonic vehicle and use the same type of intakes on those vehicles.


Bob Clark

 

[Pat Flannery]

Electric Generator Store - Portable Generator, Diesel Generators ...
http://www.electricgeneratorstore.com/

For example using the 1 to 1 thruster ratio, the 3250 watt generator
advertised for $500 could lift 3.25 kilos, about 7 pounds.

This might be a good point to mention Major de Seversky's Ion -
Propelled Aircraft:
http://www.geocities.com/CapeCanaveral/Hall/1805/ion.html
The first generation of the Lifters.

Pat

 

[Pat Flannery]

I agree the calculation does not include the effect of drag. It would
probably be analogous to the drag encountered by air-breathing methods
of space access, hypersonic craft for instance.

I don't know if you'd get much drag at all, as long as the whole surface
of the Lifter that is encountering the air is accelerating it. Drag is
induced by air encountering and flowing around a fixed surface- the
lifter would suck the air toward it from above and use it s acceleration
downwards to draw itself upwards. The difference being similar to the
difference between the bow of a ship cutting through water and a paddle
wheel pushing it backwards. In this case the vast majority of the
vehicle could be the aerodynamic equivalent of a paddle wheel.
The use of ion propulsion in regards to drag reduction gets discussed in
this article by Bill Gunston in the section about the B-2's propulsive
technique, in the section called "Stealth' about 3/5's of the way down
the webpage: http://www.aeronautics.ru/nws001/ai014.htm

Pat

 

[Pat Flannery]

You need 30,000 VDC. That generator puts out 110 VAC.

I got walloped by 20,000 VAC (or DC...I'm not sure which, except you
could do one hell of a Jacob's ladder set-up with it.) out of a furnace
ignition coil that ran on 120 VAC.
Didn't most early lifters run on flyback transformers off of computer
monitor screens?
The important thing is how much total electrical energy is being used-
not its voltage, but its wattage.

Pat

 

[Pat Flannery]

And the USAF charged the skin of an aircraft for the purpose of
being stealthy. No improvement in flight characterisitics was
noted.

Of course if they were doing it for stealth (are you referring to the
A-11 test under project Kempster?)
the results wouldn't be relevant to propulsion, as the system wouldn't
be designed to propel the aircraft, merely to cloak it in an ion cloud
as Kempster attempted:
"Such concerns led the Agency to an entirely different approach to
antiradar efforts in Project KEMPSTER. This project attempted to develop
electron guns that could be mounted on the OXCART to generate an ion
cloud in front of the plane that would reduce it's radar cross section.
Although this project proved unsuccessful, the CIA also developed a
number of more conventional ECM devices for use in the OXCART. OSA
History, chap. 20, pp. 149-151 [13 spaces] Notes on the OXCART project
by [14 spaces], OSA records, [13 spaces]"
http://www.blackbirds.net/sr71/oxcart/successortou2.html

Pat

 

[Pat Flannery]

the only benefit they give you is the reaction mass
of the surrounding air at low altitude but this
advantage will soon be outweighed by the inefficiency
of burning fuel to run a generator which in turn
powers the lifter as the air gets thinner.

If one were going to build something along these lines, this would be a
real good argument for the use of some sort of beamed power solution
that leaves the generator on the ground- say a high-powered microwave beam.

Pat

 

[bz]

I got walloped by 20,000 VAC

Ouch. Well, high voltage AC is slightly less dangerous than 110 VAC because
it is more likely to throw you clear of the circuit.

110 AC is especially dangerous because you tend to 'freeze on'.

(or DC...I'm not sure which, except you
could do one hell of a Jacob's ladder set-up with it.) out of a furnace
ignition coil that ran on 120 VAC.

Probabaly AC. Ignition coils are transformers and those produce AC. I doubt
that it was then rectified and filtered to produce DC.

Didn't most early lifters run on flyback transformers off of computer
monitor screens?

I don't know the details of how they produce the DC. Just saw that the
lifters needed 30,000 VDC.

The important thing is how much total electrical energy is being used-
not its voltage, but its wattage.

You don't generate streams of electrons and ion wind with low voltages.

Lifting will take power and high voltage.





--
bz

please pardon my infinite ignorance, the set-of-things-I-do-not-know is an
infinite set.

[email protected] remove ch100-5 to avoid spam trap

 

[N:dlzc D:aol T:com \(dlzc\)]

Dear Robert Clark:

...
The "endoatmospheric ion-propulsion" engine
is clearly the same thing as the lifter drive.

Hardly. They don't need wires to the craft.

David A. Smith

 

[N:dlzc D:aol T:com \(dlzc\)]

Dear Robert Clark:

George Dishman wrote:
....

If you look at the pages describing the drive, the
electrical power is a means to create airflow.
The thrust is due to this airflow. I'm calculating
the thrust as you do with the rocket equation.
What would be dependent on the speed is the
drag. That would be a rather complicated
dependence on the shape of the vehicle.

Especially since the shape of the vehicle would maximize the
surface for thrust, and incidentally pull a partial vaccuum to
counteract your thrust.

As a first guess you could give the craft the
aerodynmic shape of a supersonic or
hypersonic vehicle and use the same type of
intakes on those vehicles.

If you are doing the thrusting in the engine cowl, this is MHD
propulsion. It is not a "lifter".

David A. Smith

 

[Pat Flannery]

Ouch. Well, high voltage AC is slightly less dangerous than 110 VAC because
it is more likely to throw you clear of the circuit.

110 AC is especially dangerous because you tend to 'freeze on'.

Oh, I froze on real good- I froze on so good that I went jumping
violently down the boulevard with the electrified rod clamped tightly in
my hand and sparks coming out of my feet on each impact with the ground-
as the connection to the rod stuck in next to the anthill was completed.
I finally got far enough away that I pulled the wire off the coil, but
my whole right arm's muscles were contracted, and it was sore for a few
hours.
That was the last time I used a bread bag over an oven mit as a means of
high voltage protection.

Probabaly AC. Ignition coils are transformers and those produce AC. I doubt
that it was then rectified and filtered to produce DC.

I suspect it was AC also; It was basically just a big transformer, but
boy could it generate a hot arc..it had a superheated purple/yellow
plasma flame coming off the top of it.

You don't generate streams of electrons and ion wind with low voltages.

Lifting will take power and high voltage.

You know those Ionic Breeze air cleaners? If we were to take around ten
thousand of those and weld them to a spaceship, and we were in a gaseous
nebula... did I ever tell you about my plan for a rocket engine that
generates almost no thrust, but nevertheless creates an incredible
amount of noise? ;-)

Pat

 

[[email protected]]

This irritates the hell out of me. How am I supposed to learn
stuff if those who have the knowledge can't make it available?
Politics have already sewn distribution of certain doors shut.
When will the intelligentsia finish with mundane things like
science and personal finances?

Well, our Western intelligentsia turns out to be a net liability,
rather than an asset. A cancer on society, pretty much.

Imposing this kind of behaviour is extremely dangerous because
one of the things that these idiots jumped on was a memo
where he asked that people speculate about scenarios that
could happen and backup plans if they did occur.

Yes, and as you say, things like this are jumped on. The only useful
aspect of this is that it enables me to mark anyboody who expresses
outrage, *be it a world class scientist or a Nobel prize winner*, as
*moron* to be ignored.

....

I've already used it. I have a criticism but
I wish to wait until I finish because there had to be
a purpose the author organized it the way he did.

So far, most of what he has written, I've known instinctively
but could never describe in English ASCII. I'm blessing that
man's mother because he's done this work for me.

Well, just to avoid confusion, I'm assuming that this is still John
Ruscio's book you're talking about. If so, then yes, his mother is a
very nice woman, you would like her. And as for his wife, she's one
of my favorites.

Mati Meron | "When you argue with a fool,
[email protected] | chances are he is doing just the same"

 

[Robert Clark]

Dear Robert Clark:



Hardly. They don't need wires to the craft.

David A. Smith

They beam the energy to the craft using lasers or microwaves. Same
drive just different source for the power.

Bob Clark

 

[N:dlzc D:aol T:com \(dlzc\)]

Dear Robert Clark:

They beam the energy to the craft using lasers
or microwaves. Same drive just different source
for the power.

Change the thread title. An enclosed MHD drive is as much like a
lifter drive, as a turbine engine is to a house fire.

David A. Smith

 

[[email protected]]

Has there actually been any tests at low pressures ? If the pressure
was halved, then there would be less ions, but that would mean less
current. This means lower thrust but also lower power.

Is the effect that the ion keeps hitting off uncharged particles as it
is accelerated, using them as reaction mass? This also means that when
it finally hits the other terminal, it is moving very slowly.

 

[Robert Clark]

Dear Robert Clark:



Change the thread title. An enclosed MHD drive is as much like a
lifter drive, as a turbine engine is to a house fire.

David A. Smith

You can call it MHD if you want. I'm referring to any method of
propulsion that uses either electrical or magnetic fields to propel air
that has been ionized by electrical means or otherwise.
Lifters also can work on AC current. Then in addition to the force
produced by the asymmetric electric field you could get a force due to
the Lorentz force arising from the magnetic field.


Bob Clark

 

[Pat Flannery]

Has there actually been any tests at low pressures ? If the pressure
was halved, then there would be less ions, but that would mean less
current. This means lower thrust but also lower power.

It should also cut down on the danger of arcing shorting out the system.
Has anyone stacked a few lifters one on top of the other and seen if
each layer continues to accelerate the air downwards at higher velocity,
thereby generating more thrust?

Pat