Meet the SR-72

On Saturday, February 28, 2015 at 8:26:41 PM UTC+13, Fred J. McCall wrote:
William Mook wrote:

On Thursday, February 26, 2015 at 7:46:32 AM UTC+13, JF Mezei wrote:
Considering that Concorde was not exactly a financial success, and
considering it was basically early 1970s technology.

Considering also that there has been no successor to it.

It appears to me that atmospheric supersonic flight is not going to be
economically viable for the foreseable future unless some new magic
engine tech comes up.

Of current metals/carbon tech, what is the maximum sustainable speed one
could hope for in terms of skin heating for supersonic atmospheric flight ?


Now, if we go to suborbital flight, are there chances that something
like Virgin Galactic style of simple ships do the trick, or are those
not even close when it comes to sustaining re-entry ?

The new energy tech is hydrogen powered scramjet.


Well, at least it's better than you blithering on interminably about
MEMS rockets....

--
"Ordinarily he is insane. But he has lucid moments when he is
only stupid."
-- Heinrich Heine

https://www.startjoin.com/updates/project/FirstLuna/785

On Saturday, February 28, 2015 at 1:50:44 PM UTC-5, Fred J. McCall wrote:
William Mook wrote:

On Saturday, February 28, 2015 at 8:26:41 PM UTC+13, Fred J. McCall wrote:
William Mook wrote:

On Thursday, February 26, 2015 at 7:46:32 AM UTC+13, JF Mezei wrote:
Considering that Concorde was not exactly a financial success, and
considering it was basically early 1970s technology.

Considering also that there has been no successor to it.

It appears to me that atmospheric supersonic flight is not going to be
economically viable for the foreseable future unless some new magic
engine tech comes up.

Of current metals/carbon tech, what is the maximum sustainable speed one
could hope for in terms of skin heating for supersonic atmospheric flight ?


Now, if we go to suborbital flight, are there chances that something
like Virgin Galactic style of simple ships do the trick, or are those
not even close when it comes to sustaining re-entry ?

The new energy tech is hydrogen powered scramjet.


Well, at least it's better than you blithering on interminably about
MEMS rockets....


https://www.startjoin.com/updates/project/FirstLuna/785


snicker

--
"Millions for defense, but not one cent for tribute."
-- Charles Pinckney

Pinckney held racist views. Pinckney saw slavery as a positive good and could not imagine blacks as equals. He fought for the protection of the slave trade at the Constitutional Convention. Thirty years later Pickney opposed the Missouri Compromise because it set what he thought the dangerous precedent of allowing the federal Congress to outlaw slavery in the territories.

Of course he's a hero of yours.

You frigging clueless idiot.

On Tuesday, March 3, 2015 at 7:58:09 AM UTC-5, Fred J. McCall wrote:
William Mook wrote:

On Saturday, February 28, 2015 at 1:50:44 PM UTC-5, Fred J. McCall wrote:
William Mook wrote:

On Saturday, February 28, 2015 at 8:26:41 PM UTC+13, Fred J. McCall wrote:
William Mook wrote:

On Thursday, February 26, 2015 at 7:46:32 AM UTC+13, JF Mezei wrote:
Considering that Concorde was not exactly a financial success, and
considering it was basically early 1970s technology.

Considering also that there has been no successor to it.

It appears to me that atmospheric supersonic flight is not going to be
economically viable for the foreseable future unless some new magic
engine tech comes up.

Of current metals/carbon tech, what is the maximum sustainable speed one
could hope for in terms of skin heating for supersonic atmospheric flight ?


Now, if we go to suborbital flight, are there chances that something
like Virgin Galactic style of simple ships do the trick, or are those
not even close when it comes to sustaining re-entry ?

The new energy tech is hydrogen powered scramjet.


Well, at least it's better than you blithering on interminably about
MEMS rockets....


https://www.startjoin.com/updates/project/FirstLuna/785


snicker

--
"Millions for defense, but not one cent for tribute."
-- Charles Pinckney

Pinckney held racist views. Pinckney saw slavery as a positive good and could not imagine blacks as equals. He fought for the protection of the slave trade at the Constitutional Convention. Thirty years later Pickney opposed the Missouri Compromise because it set what he thought the dangerous precedent of allowing the federal Congress to outlaw slavery in the territories.

Of course he's a hero of yours.

You frigging clueless idiot.


Mookie held stupid views.

Mookie makes **** up.

Mookie is a frigging clueless idiot liar.

And the best he can do is comment on a .sig line, which only the truly
clueless do.

--
"Ordinarily he is insane. But he has lucid moments when he is
only stupid."
-- Heinrich Heine

This is a classic example of psychological projection. Someone engages in anti-social behaviour and blames the victim of that behaviour of the very thing they're doing.

The classic example of this is the rapist who claims his victim wanted him sexually.

Here I related the bald facts about Pickney - a racist. This is what history says of Pickney. Here's information from one of the official historical sites discussing him;

http://billofrightsinstitute.org/res...rles-pinckney/

Now, rather than take this data on board, Fred ignores it and spins lies around the truth of the matter, and then calls me a liar! lol.

Sad really.

Seek help dude.

On Tuesday, March 3, 2015 at 7:58:09 AM UTC-5, Fred J. McCall wrote:
William Mook wrote:

On Saturday, February 28, 2015 at 1:50:44 PM UTC-5, Fred J. McCall wrote:
William Mook wrote:

On Saturday, February 28, 2015 at 8:26:41 PM UTC+13, Fred J. McCall wrote:
William Mook wrote:

On Thursday, February 26, 2015 at 7:46:32 AM UTC+13, JF Mezei wrote:
Considering that Concorde was not exactly a financial success, and
considering it was basically early 1970s technology.

Considering also that there has been no successor to it.

It appears to me that atmospheric supersonic flight is not going to be
economically viable for the foreseable future unless some new magic
engine tech comes up.

Of current metals/carbon tech, what is the maximum sustainable speed one
could hope for in terms of skin heating for supersonic atmospheric flight ?


Now, if we go to suborbital flight, are there chances that something
like Virgin Galactic style of simple ships do the trick, or are those
not even close when it comes to sustaining re-entry ?

The new energy tech is hydrogen powered scramjet.


Well, at least it's better than you blithering on interminably about
MEMS rockets....


https://www.startjoin.com/updates/project/FirstLuna/785


snicker

--
"Millions for defense, but not one cent for tribute."
-- Charles Pinckney

Pinckney held racist views. Pinckney saw slavery as a positive good and could not imagine blacks as equals. He fought for the protection of the slave trade at the Constitutional Convention. Thirty years later Pickney opposed the Missouri Compromise because it set what he thought the dangerous precedent of allowing the federal Congress to outlaw slavery in the territories.

Of course he's a hero of yours.

You frigging clueless idiot.


Mookie held stupid views.

Mookie makes **** up.

Mookie is a frigging clueless idiot liar.

And the best he can do is comment on a .sig line, which only the truly
clueless do.

--
"Ordinarily he is insane. But he has lucid moments when he is
only stupid."
-- Heinrich Heine

Heine hated women and was a confirmed bachelor.

On Sunday, February 15, 2015 at 10:24:42 AM UTC-5, Jeff Findley wrote:
In article ,
says...
http://www.dailymail.co.uk/news/arti...ntry-hour.html

Something like the SR-72 may already be flying.


Yeah, and monkeys might fly out your butt, too, but it's pretty damned
unlikely.

Agreed. Those "mysterious flying objects" could be anything. Back in
the day, some of them were the F-117 which is decidedly subsonic,
despite the speculation at the time that a supersonic SR-71 follow-on
was in the works. So one could say that the SR-72 has been "in the
works" a long, long, *long* time based on sightings of UFOs that are
occasionally reported in the media. Popular Mechanics is likely one of
Mookie's favorite magazines for things like this.

Certainly the X-15 achieved the same velocities as those proposed
for the SR-72 back in the 1960s! We have plenty of data on that!
The X-15 achieved Mach 6.7 - higher than the proposed Mach 6.0
we're discussing here!


And you're such a technical ignoramus that you don't see the
difference between X-15 and the SR-72 proposal.

Clearly he doesn't understand the difference between a vehicle designed
primarily for short duration acceleration and one designed for cruise.

Now, while the SR-72 as designed is too small for people, and is
indeed a UAV, a larger airframe of similar shape easily carries
people while hydrogen fuels give the vehicle significant range
at Mach 6 with modest propellant fractions, while also providing
significant cooling capacity.


Ah, Magic MookieMath that assumes nothing changes as you scale things.
It's his usual game and it's still a massively ignorant belief.

But he never learns...

Scaling laws: Mookie breaks them as often as Cincinnati commuters break
the speed limit on I-275. The speedometer in my car only goes up to 85
mph, so sometimes it's hard to tell exactly how fast traffic is flowing.
;-)

Jeff
--
"the perennial claim that hypersonic airbreathing propulsion would
magically make space launch cheaper is nonsense -- LOX is much cheaper
than advanced airbreathing engines, and so are the tanks to put it in
and the extra thrust to carry it." - Henry Spencer

You people don't understand what you talk about all the time. The X-15 was an experimental aircraft designed to develop high speed cruise capability. The data developed by the programme is used for that.

http://www.odec.ca/projects/2004/flo...pulsionx43.htm

On Sunday, February 22, 2015 at 7:08:16 AM UTC-5, Fred J. McCall wrote:
William Mook wrote:

On Friday, February 20, 2015 at 1:12:46 PM UTC-5, Fred J. McCall wrote:

Note that Mookie has now changed his story from

"the X-15 having taught us "precisely what we need to know to build a Hypersonic Transport plane" to
'something learned from the X-15 program is valuable in building a Mach 6 aircraft".

Those are two very different propositions,


A Hypersonic Transport Plane is a long distance aircraft that travels between Mach 6 and Mach 8.
The X-15 is a short range research craft that travels between Mach 6 and Mach 8.

So, how is building a Hypersonic Transport Plane NOT building an aircraft that travels as fast as the X-15?

Apart from range and staying power, its the same thing!


Gee, building a hydrogen bomb is exactly like building a hand grenade!
They both go 'boom'.


Specifically how is the X-15 experience NOT helpful in understanding the critical factors
of drag, heat rate, lift to drag, that must be known and understood in order to build a
Hypersonic Transport Plane?


Oh, all those little details that Magic Mookie Math likes to ignore;
issues of scale, materials, power, etc.


The answer is, the X-15 is ESSENTIAL to understanding how to build a HST..


Bull****.


So, why promote the artificial division of HST and X-15?


Nothing 'artificial' about it. Why do you think you can ignore the
huge differences between the two?


Is the X-15's lack of an airbreathing engine or it's short range or even it's highly limited
staying power at speed, all quite different and all required of the HST enough to enforce
the highly artificial division and enforced ignorance of the NECESSARY fundamentals of high
speed flight? Only among the propagandists of the criminal US military who seeks to restrict
from general discussion and public discourse any real appreciation of what is required to create
a commercial HST. Because general knowledge of this range of speeds is critical not only to the
success of the HST, but to efficient space launch and ballistic transport and re-entry as well.


So if it's always so simple, shut up and build some actual working
hardware, you ignorant ****.



but not only is Mookie not bright enough


Who do you believe? Someone who explains precisely what's going on and why?
OR someone who merely calls names and casts aspersions and never explains
in any sensible way their views?


Mookie, you do a much better job of demonstrating just how stupid you
are than I ever could.



to realize that,


Realize what?


Put the sentence back together and the answer to your question is
obvious, you silly little ****e.



he thinks everyone else is not bright enough to realize it, either.

I am and always have been speaking to those who are reading this who are bright enough to understand me.


I understand you perfectly, Mookie. That's why you have a problem
with me.



snip Mookwriggling

--
"Ignorance is preferable to error, and he is less remote from the
truth who believes nothing than he who believes what is wrong."
-- Thomas Jefferson

You misquote Jefferson too. Jefferson wouldn't like you and what you're doing to his country.


Only the truly clueless comment on .sig lines, Mookie.

--
"Ordinarily he is insane. But he has lucid moments when he is
only stupid."
-- Heinrich Heine

A hydrogen bomb is typically initiated is with a small fission blast. The fission blast is initiated by an explosive assembly of fissile materials. This involves a small shaped plastic explosive charge that compresses the fissile material. The same type of plastic explosive modern hand grenades are made of.

http://en.wikipedia.org/wiki/Composition_C

http://nuclearweaponarchive.org/Library/Implsion.html

http://nuclearweaponarchive.org/Library/Teller.html

The choice of materials available in 1950 or 2020 do not change the aeroelasticity of air and its thermodynamic properties when disturbed by the passage of an object moving at 6x the speed of sound in air.

To restate, the rate at which power is dissipated across a surface due to skin friction whilst traveling through air at Mach 6 doesn't depend on what you choose to make the skin out of.

I think it funny that you rant on this point cluelessly projecting your ignorance on to others who obviously understand vastly more of this subject than you do.

Let's look at the aerodynamics of the X-15. And there's no better source than NASA TM-X 2056 DRAG CHARACTERISTICS OBTAINED FROM SEVERAL CONFIGURATIONS OF THE MODIFIED X-15-2 AIRPLANE UP TO MACH 6.7 by Larry Montoya from Edwards Flight Research Center published in Aug 1970.

The X-15 used an NACA 66005 airfoil section and we can see from the data provided that power dissipated by skin friction was 1/24th the power needed to maintain level flight at Mach 6.

Total surface area of the aircraft fuselage was 18.6 m2. The aircraft required 9,100 Newtons to maintain level flight (at 6,620 kg weight) At 2,000 m/sec this thrust generates

Power = Force x Velocity = 9,100 x 2,000 = 18.2 MW

Now dividing this figure by 24 obtains 0.76 MW of heat load to the skin. Dividing by 18.6 m2 obtains 40.9 kW/m2 specific heating at this speed.

Now, a hydrogen fueled scramjet that's 65% efficient must consume fuel at a rate of 28 MW to power the X-15 in level flight at Mach 6. Hydrogen fuel requires 198.1 grams per second in an engine to produce this level of thrust and power.

Now from 14K to 20.4K hydrogen absorbs 25.6 Joules per gram. Another 58.6 Joules per gram to liquefy the solid hydrogen in solution. Another 400 J/gram to vaporize the liquid. Another 2,746 J/gram to heat the vapor from 20..4 K to 295 K. (22C) A total of 3,230.2 Joules/gram. Consuming 198.1 grams per second absorbs 0.64 MW of heating.

Thus if as much as 84% of this heat load is transmitted into the skin of the aircraft, it can be effectively cooled to room temperature. Even if ALL the heat load were transmitted into the skin of the aircraft, it would require the hydrogen to be heated to 356 K before injection.

Of course, heat loads into the skin of the aircraft are nowhere near 84% of the total, but it does show the ability of slush hydrogen to maintain cool aircraft temperatures without the need of exotic materials.

Modern 3D printing fabrication technologies permit very sophisticated channels to be constructed in the skin of aircraft made of quite common materials such as titanium.

http://3dprint.com/12262/ge-ebm-3d-printing/
http://www.arcam.com/

The major game changer today, is the development of light weight powerful fuel cell technology. With very light weight and very powerful fuel cell technologies hydrogen is best used to generate electricity which is used in a hypersonic MHD channel to provide thrust. This 1999 AIAA paper, "Thermodynamic Cycle Analysis of Magnetohydrodynamic-Bypass Airbreathing Hypersonic Engines" by Ron J. Litchford of NASA, Marshall Space Flight Center, Valentine A. Bityurin of the Institute of High Temperatures (IVTAN), Russian Academy of Sciences, John T. Linebeny of LyTec Incorporated, commercial licensee of this technology, provides the technical details - for those interested in understanding this opportunity.

https://archive.org/details/nasa_techdoc_20000032786

In combination with subsonic electric lift possible with powerful lightweight electrical sources, we can see on the horizon aircraft with no moving parts (other than air) capable of high vertical take off and landing and rapid acceleration to high speed flight, with the ability to sustain that flight.

Materials can exist in four different forms. In order of increasing temperature you have;

(1) Solid,
(2) Liquid,
(3) Gas,
(4) Plasma,

In a solid the forces between the atoms of the material dominate and hold the atoms in rigid positions relative to one another. In a liquid the kinetic energy of the atoms just equals the forces that the atoms feel from one another. As a result, the atoms slide past one another, stuck together, but not in a rigid frame. In a gas the kinetic energy is even higher, larger than the energies that the atoms exert on one another. As a result, the atoms travel in straight lines until they scatter off one another. In a plasma the kinetic energy is larger than the energies holding the electrons in place around the atoms. So, the electrons and the charged atoms from which they come - the ions - scatter off one another - and exhibit various electrical and magnetic properties.

Now temperature is a measure of internal energy that is proportional to the kinetic energy of the atoms and molecules of which a substance is made. It is proportional for this reason to the square root of the average velocity of the molecules. To raise temperature requires that energy be added. To lower temperature requires that energy be removed.

So, we now know how to think about something like water - it can be a piece of ice, it can be a cup of liquid, it can be steam boiling off a pot. Anyone who cooks or eats is familiar with these different states of water. All stable materials exhibit similar properties. It takes energy to raise the temperature of ice. When you reach the melting point, it takes a lot of energy to convert the ice to liquid, with no increase in temperature. Then, after you have a liquid, you can raise temperature by putting more energy into the liquid. Until you reach the boiling point. Then, you have to put a lot of energy into the liquid to turn it into gas, before its temperature rises again. Then after you have steam, you can begin to heat steam up.

That is, you have phase changes that require the absorption of energy. Now if we wanted to start with cold ice, and pump it around, we couldn't do that with a block of ice. But we could do it with ice particles suspended in liquid. This is called a slush. Anyone who eats icecream, or has ordered a Slushee - knows about slush.

Alright, so, hydrogen is a gas at room temperature. It boils at -252.9 C at normal pressures. It solidifies at -259.2 C at normal pressures. At slightly higher pressures, these temperatures can be lowered.

It takes 117 kilojoules of energy per kilogram of hydrogen to liquefy it.

It takes 461 kilojoules of energy per kilogram of hydrogen to vaporize it.

It takes 13.2 kilojoules of energy per kilogram of hydrogen to raise it 1 degree Celsius when its solid.

It takes 14.3 kilojoules of energy per kilogram of hydrogen to raise it 1 degree Celsius when its liquid.

It takes 14.4 kilojoules of energy per kilogram of hydrogen to raise it 1 degree Celsius when its gas near room temperature.

So, if you have Slush hydrogen in a tank at -270 C and raise it to room temperature +22 C it absorbs 4.8 megajoules of energy.

State delta C kJ/kg/C kJ/kg
-270.0
-259.2 10.8 13.2 142.56
-252.9 6.3 14.3 90.09
+ 22.0 274.9 14.4 3,958.56

Solid to Liquid 111.15
Liquid to Gas 461.00

Total 4,763.36

Now hydrogen is also a fuel. When you burn it with oxygen it releases 141.3 megajoules of energy per kilogram producing 9 kilograms of water vapor.

In a jet engine operating at peak propulsive efficiency, which is the case at cruise, we have efficiencies of 65%. That means that 65% of the energy in the fuel end up in the kinetic energy of the vehicle. So, each kilogram of hydrogen contributes 91.8 megajoules of energy to the vehicle.

A vehicle with 7 to 1 Lift to Drag requires 1/7th of its energy appear as thrust to overcome drag in level flight. A vehicle that weighs 70,000 kg and has L/D of 7 needs 10,000 kg of thrust to maintain level flight. An engine that is moving at 2 km/sec while exerting 10,000 kg of thrust is expending power at a rate of

2,000 x 10,000 x 9.80655 = 196.1 MW.

An engine that is 65% efficient in cruise, and burns hydrogen requires

196.1 / 0.65 / 141.3 = 2.2 kg/sec

fuel flow rate to maintain that thrust.

A vehicle where 1 joule of energy is generated by skin friction for every 24 joules of kinetic energy dissipated by the vehicle - that means that at most heat must be removed from the skin at a rate of;

196.1 / 24 = 8.2 MW.

This means that slush hydrogen must be warmed to room temperature at a rate of

8.2 / 4.8 = 1.7 kg/sec

Which gives us excess cooling capacity for a hypersonic hydrogen powered transport, even if there is no insulation between the skin and the surrounding air.

The existence of ionic thrusters that control plasma flow at high speed, combined with the existence of solid oxide fuel cells, that operate efficiently at high temperature, permit the construction of a supersonic scramjet that operates externally with electric and magnetic fields to compress, heat and expand air across a surface.

http://www.space-travel.com/reports/...rst_999. html

Operating within a disk like lifting body propelled by ionic thruster powered by hydrogen fuel cell using atmospheric oxygen - a very capable craft is built.

Such a disk, is capable of vertical take off and landing, and also capable of maintaining an L/D of 8 to 1 through the subsonic, supersonic, and hypersonic range, with the other characteristics we've discussed when flying at an angle of attack of 12 degrees to 20 degrees.

This from data developed Fred Demele at Ames Research Center NASA technical note D-788

https://archive.org/stream/nasa_tech...ge/n0/mode/2up


Crew: Five (3 flight deck)
Capacity: 98 passengers
Payload: 33,800 lb (7938 kg)
Length: 99 ft 0 in (30.18 m)
Span: 99 ft 0 in (30.18 m)
Height: 27 ft 7 in (8.41 m)
Empty weight: 57,400 lb (26,036 kg)
Max. takeoff weight: 113,000 lb (51,256 kg)
Powerplant: 8 × fuel cell engines, 32,800 ehp (24,000 kW) each
Hydrogen Capacity: 47,960 lb (21,800 kg)


Maximum speed: 3900 knots (4480 mph, 7210 km/h) at 120,000 ft (36,600 m)
Cruise speed: 3240 knots (3730 mph, 6000 km/h)
Range: 19,130 nmi (22,000 mi, 35,400 km) with maximum payload
Service ceiling: 320,000 ft (97,530 m)
Rate of climb: 3,940 ft/min (20 m/s)


Smaller version with many of the same features;

http://www.hitechweb.genezis.eu/UFOp...SilverBug1.jpg

So, we have a 99 foot diameter disk, that is 16 feet 5 inches tall, at the centre of which is a 27 foot 7 inch tall sphere containing the hydrogen needed for the vehicle's globe circling range.

With three billions air passengers per year total demand, 98 passengers per vehicle above, and a one hour turn around time, 3,492 discs of the type described above could replace the 16,000 airliners operating today and provide superior service.

On Thursday, March 19, 2015 at 8:40:31 PM UTC-4, William Mook wrote:
Materials can exist in four different forms. In order of increasing temperature you have;

(1) Solid,
(2) Liquid,
(3) Gas,
(4) Plasma,

In a solid the forces between the atoms of the material dominate and hold the atoms in rigid positions relative to one another. In a liquid the kinetic energy of the atoms just equals the forces that the atoms feel from one another. As a result, the atoms slide past one another, stuck together, but not in a rigid frame. In a gas the kinetic energy is even higher, larger than the energies that the atoms exert on one another. As a result, the atoms travel in straight lines until they scatter off one another. In a plasma the kinetic energy is larger than the energies holding the electrons in place around the atoms. So, the electrons and the charged atoms from which they come - the ions - scatter off one another - and exhibit various electrical and magnetic properties.

Now temperature is a measure of internal energy that is proportional to the kinetic energy of the atoms and molecules of which a substance is made. It is proportional for this reason to the square root of the average velocity of the molecules. To raise temperature requires that energy be added. To lower temperature requires that energy be removed.

So, we now know how to think about something like water - it can be a piece of ice, it can be a cup of liquid, it can be steam boiling off a pot. Anyone who cooks or eats is familiar with these different states of water. All stable materials exhibit similar properties. It takes energy to raise the temperature of ice. When you reach the melting point, it takes a lot of energy to convert the ice to liquid, with no increase in temperature. Then, after you have a liquid, you can raise temperature by putting more energy into the liquid. Until you reach the boiling point. Then, you have to put a lot of energy into the liquid to turn it into gas, before its temperature rises again. Then after you have steam, you can begin to heat steam up.

That is, you have phase changes that require the absorption of energy. Now if we wanted to start with cold ice, and pump it around, we couldn't do that with a block of ice. But we could do it with ice particles suspended in liquid. This is called a slush. Anyone who eats icecream, or has ordered a Slushee - knows about slush.

Alright, so, hydrogen is a gas at room temperature. It boils at -252.9 C at normal pressures. It solidifies at -259.2 C at normal pressures. At slightly higher pressures, these temperatures can be lowered.

It takes 117 kilojoules of energy per kilogram of hydrogen to liquefy it.

It takes 461 kilojoules of energy per kilogram of hydrogen to vaporize it..

It takes 13.2 kilojoules of energy per kilogram of hydrogen to raise it 1 degree Celsius when its solid.

It takes 14.3 kilojoules of energy per kilogram of hydrogen to raise it 1 degree Celsius when its liquid.

It takes 14.4 kilojoules of energy per kilogram of hydrogen to raise it 1 degree Celsius when its gas near room temperature.

So, if you have Slush hydrogen in a tank at -270 C and raise it to room temperature +22 C it absorbs 4.8 megajoules of energy.

State delta C kJ/kg/C kJ/kg
-270.0
-259.2 10.8 13.2 142.56
-252.9 6.3 14.3 90.09
+ 22.0 274.9 14.4 3,958.56

Solid to Liquid 111.15
Liquid to Gas 461.00

Total 4,763.36

Now hydrogen is also a fuel. When you burn it with oxygen it releases 141.3 megajoules of energy per kilogram producing 9 kilograms of water vapor.

In a jet engine operating at peak propulsive efficiency, which is the case at cruise, we have efficiencies of 65%. That means that 65% of the energy in the fuel end up in the kinetic energy of the vehicle. So, each kilogram of hydrogen contributes 91.8 megajoules of energy to the vehicle.

A vehicle with 7 to 1 Lift to Drag requires 1/7th of its energy appear as thrust to overcome drag in level flight. A vehicle that weighs 70,000 kg and has L/D of 7 needs 10,000 kg of thrust to maintain level flight. An engine that is moving at 2 km/sec while exerting 10,000 kg of thrust is expending power at a rate of

2,000 x 10,000 x 9.80655 = 196.1 MW.

An engine that is 65% efficient in cruise, and burns hydrogen requires

196.1 / 0.65 / 141.3 = 2.2 kg/sec

fuel flow rate to maintain that thrust.

A vehicle where 1 joule of energy is generated by skin friction for every 24 joules of kinetic energy dissipated by the vehicle - that means that at most heat must be removed from the skin at a rate of;

196.1 / 24 = 8.2 MW.

This means that slush hydrogen must be warmed to room temperature at a rate of

8.2 / 4.8 = 1.7 kg/sec

Which gives us excess cooling capacity for a hypersonic hydrogen powered transport, even if there is no insulation between the skin and the surrounding air.

The existence of ionic thrusters that control plasma flow at high speed, combined with the existence of solid oxide fuel cells, that operate efficiently at high temperature, permit the construction of a supersonic scramjet that operates externally with electric and magnetic fields to compress, heat and expand air across a surface.

http://www.space-travel.com/reports/...rst_999. html

Operating within a disk like lifting body propelled by ionic thruster powered by hydrogen fuel cell using atmospheric oxygen - a very capable craft is built.

Such a disk, is capable of vertical take off and landing, and also capable of maintaining an L/D of 8 to 1 through the subsonic, supersonic, and hypersonic range, with the other characteristics we've discussed when flying at an angle of attack of 12 degrees to 20 degrees.

This from data developed Fred Demele at Ames Research Center NASA technical note D-788

https://archive.org/stream/nasa_tech...ge/n0/mode/2up


Crew: Five (3 flight deck)
Capacity: 98 passengers
Payload: 33,800 lb (7938 kg)
Length: 99 ft 0 in (30.18 m)
Span: 99 ft 0 in (30.18 m)
Height: 27 ft 7 in (8.41 m)
Empty weight: 57,400 lb (26,036 kg)
Max. takeoff weight: 113,000 lb (51,256 kg)
Powerplant: 8 × fuel cell engines, 32,800 ehp (24,000 kW) each
Hydrogen Capacity: 47,960 lb (21,800 kg)


Maximum speed: 3900 knots (4480 mph, 7210 km/h) at 120,000 ft (36,600 m)
Cruise speed: 3240 knots (3730 mph, 6000 km/h)
Range: 19,130 nmi (22,000 mi, 35,400 km) with maximum payload
Service ceiling: 320,000 ft (97,530 m)
Rate of climb: 3,940 ft/min (20 m/s)


Smaller version with many of the same features;

http://www.hitechweb.genezis.eu/UFOp...SilverBug1.jpg

So, we have a 99 foot diameter disk, that is 16 feet 5 inches tall, at the centre of which is a 27 foot 7 inch tall sphere containing the hydrogen needed for the vehicle's globe circling range.

With three billions air passengers per year total demand, 98 passengers per vehicle above, and a one hour turn around time, 3,492 discs of the type described above could replace the 16,000 airliners operating today and provide superior service.

A 99 foot diameter disk that forms an ellipse 16 feet thick at its center, with a 27 foot 7 inch diameter sphere at its center has two 6 foot tall domes sticking out above and blow the disk. Each 22 ft 10 inches in diameter - with an angle of 35 degrees from a flatter surface that is angled at 9 degrees at that radius.

A triangular landing gear - each with a built in air stair - holds the craft upon landing and absorbs any shocks. An annular hall with an interior diameter of 27 foot 7 inches and an exterior diameter of 88 feet 4 inches and a 7 foot 3 inch cabin height. At 33 foot diameter the single floor of the outer rim breaks into two floors one above one below.

This gives a total deck area of

(((88 + 4/12)/2)^2 - (33/2)^2)*pi() = 5,273 sq ft.

for the outer deck and

(((33/2)^2) - ((27+7/12)/2)^2)*pi()*2 = 515 sq ft.

for the two inner decks.

The upper inner deck is the control/crew cabin. The lower inner deck is the entry/egress area and cargo handling. The interior cabin is supported inside the outer shell by two inverted hexapod positioners.

http://www.newsmax.de/bilder/130725_70476.jpg

Three perpendicular inertia wheels each 2 ft 10 inches in diameter circle around the spherical hydrogen tank, each oriented along a different axis to provide precise attitude control of the craft.

https://www.youtube.com/watch?v=n_6p-1J551Y

The hexapod positioners work in conjunction with the inertia wheels and the propulsive system to maintain smooth flight conditions to the passengers and crew. Reducing or eliminating all side forces during flight.

Autostereoscopic displays built into the walls and ceiling of the aircraft provide a seamless 3D view of the outside world provided by panoramic array of cameras looking around the craft.

http://appleinsider.com/articles/08/...lay_har dware

http://www.technology-licensing.com/...-displays.html

http://www.telegraph.co.uk/news/avia...of-flying.html

A pilot, and crew, to provide emergency services as well as concierge services during the flight, relies totally on automated drone technology to fly from one point to another on Earth. The aircraft is networked with all other aircraft and individuals use an app to find the closest aircraft and bid for a flight to go somewhere. Flights are then assigned on an ad hoc basis to the highest bidders. The system self-organizes to maximize revenue flow whilst simultaneously minimizing costs to passengers.

A Mach 6 aircraft carrying 98 passengers half way around the world provides one level of service. A Mach 2 aircraft carrying 33 passengers a thousand miles, provides another level of service. A Mach 0.8 aircraft carrying 12 passengers 100 miles provides another level of service.

300 mph - 9 minutes - 45 miles - 4 passenger - 475,000 vehicles
610 mph - 18 minutes - 183 miles - 12 passenger - 190,000 vehicles
1,522 mph - 40 minutes - 1,014 miles - 33 passenger - 11,000 vehicles
4,480 mph - 150 minutes - 11,200 miles - 98 passenger - 9,000 vehicles

A network of vehicles providing door to door VTOL service anywhere on Earth in four hours or less.

Flights/Hour Passengers/Vehicle Hours/Year Vehicles Passengers/Year

6.0 4 8766 475000 = 10.00 billion
3.0 12 8766 190000 = 6.00 billion
1.5 33 8766 11000 = 4.75 billion
0.4 98 8766 9000 = 3.09 billion

These operate over the entire land area of Earth, So;

Distance Area sq miles Number Aircraft Slow Fast

45 5,261.1 10,924 475,000 43 17 Local
183 87,007.0 661 190,000 287 16 Regional
1,014 2,671,331.6 22 11,000 511 418 Global
9,000

On Friday, March 20, 2015 at 3:08:48 AM UTC-4, JF Mezei wrote:
On 15-03-19 20:40, William Mook wrote:

It takes 117 kilojoules of energy per kilogram of hydrogen to liquefy it.

It takes 461 kilojoules of energy per kilogram of hydrogen to vaporize it.


I take it the 117 kilojoules is the energy to compress the gas ? And
some 461kJ will be released in heat when you liquidy it by compressing it ?

Compression is something different than state change and specific heat.