Plasma window vacuum airship?

[Angeltxilon]

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A vacuum airship, also known as a vacuum balloon, is a hypothetical airship that is evacuated rather than filled with a lighter-than-air gas such as hydrogen or helium.

-snip-

An airship operates on the principle of buoyancy, according to Archimedes' principle. In an airship, air is the fluid in contrast to a traditional ship where water is the fluid.

The density of air at standard temperature and pressure is 1.28 g/l, so 1 liter of displaced air has sufficient buoyant force to lift 1.28 g. Airships use a bag to displace a large volume of air; the bag is usually filled with a lightweight gas such as helium or hydrogen. The total lift generated by an airship is equal to the weight of the air it displaces, minus the weight of the materials used in its construction including the gas used to fill the bag.

Vacuum airships would replace the helium gas with a near-vacuum environment and would theoretically be able to provide the full lift potential of displaced air, so every liter of vacuum could lift 1.28 g. Using the molar volume, the mass of 1 liter of helium (at 1 atmospheres of pressure) is found to be 0.178 g. If helium is used instead of vacuum, the lifting power of every liter is reduced by 0.178 g, so the effective lift is reduced by 14%. A 1 liter volume of hydrogen has a mass of 0.090 g.

The main problem with the concept of vacuum airships however is that with a near-vacuum inside the airbag, the atmospheric pressure would exert enormous forces on the airbag, causing it to collapse if not supported. Though it is possible to reinforce the airbag with an internal structure, it is theorized that any structure strong enough to withstand the forces would invariably weigh the vacuum airship down and exceed the total lift capacity of the airship, preventing flight.

[...]

Fount: https://en.wikipedia.org/wiki/Vacuum_airship

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The plasma window (not to be confused with a plasma shield) is a technology that fills a volume of space with plasma confined by a magnetic field. With currenttechnology, this volume is quite small and the plasma is generated as a flat plane inside a cylindrical space.

Plasma is any gas that has had some of its atoms or molecules ionized and is generally held to be a separate phase of matter. This is most commonly achieved by heating the gas to extremely high temperatures, although other methods also exist. Plasma becomes increasingly viscous (thick) at higher temperatures, to the point where other matter has trouble passing through.

A plasma window's viscosity allows it to separate gas at standard atmospheric pressure from a total vacuum, in fact it is reported that it can withstand a pressure difference of up to nine atmospheres. At the same time, the plasma window will allow radiation such as lasers and electron beams to pass. This property is the key to the plasma window's usefulness — the technology of the plasma window permits for radiation that can only be generated in a vacuum to be applied to objects in an atmosphere.One of the major applications of this technology is electron beam welding, where it has made EBW practical outside of a hard vacuum.

-snip-

The physical properties of the plasma window vary depending on application, but so far most have been generated at temperatures around 15,000 Kelvin.

The only limit to the size of the plasma window are current energy limitations as generating the window consumes around 20 kilowatts per inch (8 kW/cm) in the diameter of a round window.

[...]

https://en.wikipedia.org/wiki/Plasma_window

I am interested in the vacuum airship idea, lately I was wondering if is possible a vacuum airship based on plasma.

Suppose we generate a plasma bubble with vacuum inside (by plasma technology window) as large as it can be an airship, obviously it requires a lot of energy, perhaps even a nuclear reactor to maintain such bubble.

This would be impractical and very expensive compared to a normal airship, but their biggest advantage is that, being made of plasma and with the correct form, its friction with the air, though it be at high speeds, would be very small.
Can you imagine an airship made of plasma, able to fly, not at supersonic or hypersonic speeds, but atmospheric reentry (ultrasonic) speeds? A airship capable to go as fast as lightning?

 

Is this viable or possible currently or in a near future?

 

[Steel]

31 minutes ago, Angeltxilon said:

 

 

I am interested in the vacuum airship idea, lately I was wondering if is possible a vacuum airship based on plasma.

Suppose we generate a plasma bubble with vacuum inside (by plasma technology window) as large as it can be an airship, obviously it requires a lot of energy, perhaps even a nuclear reactor to maintain such bubble.

This would be impractical and very expensive compared to a normal airship, but their biggest advantage is that, being made of plasma and with the correct form, its friction with the air, though it be at high speeds, would be very small.
Can you imagine an airship made of plasma, able to fly, not at supersonic or hypersonic speeds, but atmospheric reentry (ultrasonic) speeds? A airship capable to go as fast as lightning?

 

Is this viable or possible currently or in a near future?

 

Considering this plasma window apparently has the capacity to keep nine atmospheres of pressure separate from a vacuum, why would it have any less air resistance than another material with similar properties?

Edited April 1, 2016 by Steel

[PB666]

10 minutes ago, Angeltxilon said:

 

 

I am interested in the vacuum airship idea, lately I was wondering if is possible a vacuum airship based on plasma.

Suppose we generate a plasma bubble with vacuum inside (by plasma technology window) as large as it can be an airship, obviously it requires a lot of energy, perhaps even a nuclear reactor to maintain such bubble.

This would be impractical and very expensive compared to a normal airship, but their biggest advantage is that, being made of plasma and with the correct form, its friction with the air, though it be at high speeds, would be very small.
Can you imagine an airship made of plasma, able to fly, not at supersonic or hypersonic speeds, but atmospheric reentry (ultrasonic) speeds? A airship capable to go as fast as lightning?

 

Is this viable or possible currently or in a near future?

 

Plasma is extremely reactive, it strips electrons off of any material it contacts as it cools (which in general is a very high temperature compared to stable temperature of most metals, when it hits solids it transmitts its kinetic energy and then steals electrons off the surface). You could generate the same effect if you could find a vapor that caged a positive charge in its interior, in this way it would not need to be hot. The problem with this however is it becomes very energetic to confine significant amount to small spaces. The natural equation is PV = nRT where avagadros number defines rationalizes n. As a consequence natural pressure of such a substance would be much lower per unit mass of such caged charge because of the mass required to create the cage. Creating pressure is work, and therefore the charge repulsions created constitute the input of energy. One possible molecule might be a bucky ball with Iron3+ inside of it.

Either vacuum or plasma have to deal with the fact that the atmospheric pressure drops rapidly, they both rely on boyancy of space, to support any given unit of mass, the volumn of boyant space required doubles with altitude unit, this is refered to atmoshere scale, in kerbal is a fall in pressure of 2.6 for each 5000 meters. Exemplary that if you are at MSL pressure is 1, at 5000 pressure is 1/2.6, at 10000 its 1/2.6², at 15000 its 1/2.6³ and so on,

If you had a volume lets say 1.5 cubic meters at MSL that can support a kg of total weight, at 5000 meters it would need to be 3.9 cubic meters, at 10000 10.26 cubic meters (on earth it would only need to be 4.5, kerbal scales out faster, but it gravity also drops faster), at 15000 its 26.364, eventually the structure that contains the media weights more than the bouyancy.

But lets just say this wasn't the problem, lets just say you could float as high as you want, you are still not in orbit, you still have to add 7800 dV and the bigger the profile of your ship, the harder this would be. So for example suppose I wanted to do a Hohmann transfer to mars, if I am floating I don't get to take advantage of oberth affect or burn windows, although I am traveling with the surface, still I am moving slowly. If I tried to circularize my orbit I would have to face huge amounts of drag.

[AngelLestat]

Hi Angeltxilon, I will discard the plasma window idea for airships, you need a huge amount of energy to make it, it also radiates a lot of heat away due the 15000 Kelvin degress that it needs, to make such big plasma you also need a huge structure.

But the vacuum airship idea is not bad if we are talking of really big scales.
There is no real difference between the bouyancy you get with hydrogen or helium vs vacuum, also pure vacuum takes a lot of energy to make, because you will need to make it variable so you can control your bouyancy.
At small scales this is really silly, but the surface / volume relation changes with scale.

Each time you increase the diameter of a sphere by a 25%, volume doubles and surface only increase a 60%, so if you measure how that volume/surface ration changes each time you increase a 25% the diameter you get: 8, 17, 33, 67, 133, 267.   This mean than in just 6 steps increasing the diameter a 25%, the surface / volume  ratio is 1/267, this mean that the surface (structure mass needed) it becomes negligible vs your lifting that you get from that volume.

We can use as structure Geodesic spheres:

https://www.youtube.com/watch?v=OuwHsQgRDn4
Is the only structure that becomes stronger at bigger sizes, there is another video in the links that show the same structure with a guy in each triangle, is also the structure more faster to build.

That it will stand vacuum without issue, but you dont need to achieve vacuum, if your outside pressure is 5 times higher, then with that volume you get a huge amount of lift, the problem with vacuum is that any hole will demand considerable energy in your vacuum pumps to keep the pressure differential, is not just a big issue but it becomes a lot more effective if you reduce your pressure differential.

Buckminster Fuller who was the inventor who discover all the properties of geodesic spheres said that if you have 1 km radius sphere, and you just increase the inside temperature 1 degree due passive solar radiation and greenhouse effect, you get a huge amount of lift enough to rise a small colony.

 

PD: as vehicle to reach space it seems not worth it.

Edited April 1, 2016 by AngelLestat

[KerikBalm]

Considering the power requirements, I think you'd find that you'd be better off just using helium and taking the 14% hit to bouyancy... instead of the massive energy storage/reactor/generator you'd need to keep those plasma windows operating

[fredinno]

5 hours ago, Angeltxilon said:

 

 

I am interested in the vacuum airship idea, lately I was wondering if is possible a vacuum airship based on plasma.

Suppose we generate a plasma bubble with vacuum inside (by plasma technology window) as large as it can be an airship, obviously it requires a lot of energy, perhaps even a nuclear reactor to maintain such bubble.

This would be impractical and very expensive compared to a normal airship, but their biggest advantage is that, being made of plasma and with the correct form, its friction with the air, though it be at high speeds, would be very small.
Can you imagine an airship made of plasma, able to fly, not at supersonic or hypersonic speeds, but atmospheric reentry (ultrasonic) speeds? A airship capable to go as fast as lightning?

 

Is this viable or possible currently or in a near future?

 

Wouldn't putting plasma in increase the mass, and null the reason for having a vacuum inside in the first place?

[Angeltxilon]

1 hour ago, fredinno said:

Wouldn't putting plasma in increase the mass, and null the reason for having a vacuum inside in the first place?

Plasma generated by plasma windows, as all the plasmas generated artificially until now, has a very little density, 10 or even 100 times minor to molecular hydrogen gas at room pressure.

The main problem is the required energy, that would do to the plasma airship to require heavy nuclear energy generators, and the heavy anti-radiation protection.

Another problem would be if such plasma window has losses of plasma (could happen in big models), will require reserves of the used gas to obtain the plasma.

Edited April 1, 2016 by Angeltxilon

[magnemoe]

Any leak will be an major issue, note that on an helium balloon small holes is an periodic maintenance issue nothing more, the pressure difference is to low to generate much leak
An vacuum balloon will have around one bar pressure difference

[fredinno]

1 hour ago, magnemoe said:

Any leak will be an major issue, note that on an helium balloon small holes is an periodic maintenance issue nothing more, the pressure difference is to low to generate much leak
An vacuum balloon will have around one bar pressure difference

I think that was the point of the plasma.

9 hours ago, Angeltxilon said:

Plasma generated by plasma windows, as all the plasmas generated artificially until now, has a very little density, 10 or even 100 times minor to molecular hydrogen gas at room pressure.

The main problem is the required energy, that would do to the plasma airship to require heavy nuclear energy generators, and the heavy anti-radiation protection.

Another problem would be if such plasma window has losses of plasma (could happen in big models), will require reserves of the used gas to obtain the plasma.

Yeah, so it would increase the mass.

[AngelLestat]

On 2/4/2016 at 1:13 AM, magnemoe said:

Any leak will be an major issue, note that on an helium balloon small holes is an periodic maintenance issue nothing more, the pressure difference is to low to generate much leak
An vacuum balloon will have around one bar pressure difference

Helium has a big drawback, is expensive, this mean that you can not design an airship able to lift a big payload, or reach high altitude without vent lifting gas or had good speed or range.
In my opinion, helium airships are only useful in application where you need extra safety measures, less than 50 ton of payload and short range or altitude variance.

Hydrogen cost 15 times less and can be used as fuel or can be easily produced locally by the same airship using water, this can be also used as ballast, you just need a flying certificate to allow it and a no flammable envelope. But even with all that it reach a point in the payload and altitude variance in which the vacuum airships becomes more cost effective.

Vacuum Airship with magnetic accelerator for sat launch: 

Avoid the use of lifting gases had many advantages, you can control your buoyancy very easy just pumping air out or allowing air in (recovering part of the pumping energy), if you want variable buoyancy with lifting gases you need the aeroscraft method, in which many internal pressure envelope are used to compress the helium with another envelope that is filled with external air, this increase considerable the total surface envelope needed.

So when the sphere's diameter is doubled it will quadruple its square footage and produce eight times the volume, in this case surface is structure mass and volume = lift capacity.

An ellipsoid of 300mx150mx150m has a volume of 28274333m3 and a surface of 482977m2, if we allow a pressure differential of 0.2 bar, then we can lift 5700 tons close to the surface and 8400 tons at 10000m (0.25 bar - 0.2 bar = 0.05 bar inside the envelope), external temperature -50c.
We can allow heat the inside air using sunlight to equal lifting capacity on the surface.
That amount of lift divided by the surface give us 18kg/m2, if we remove extra kg for payload and engines we have 13kg/m2 to support that pressure diferential, if we double the side of the airship we have 26kg/m2.
But those 13kg would be more than enough to stand a 0.2 bar difference.

Now we can include in the middle a tube of the airship an magnetic accelerator of 500m of long, this mean that oversize the envelope by 100 meters that needs to be supported by cables.
This is a rough acceleration that not allow manned vehicles, but it can launch sats that will finish their last burn in space. 

Some methods to allow 1 bar pressure differential:

http://aoi.com.au/Originals/VacuumBalloon.pdf  (vacuum airships possible designs)

http://www.google.com/patents/US20060038073#v=onepage&q&f=false  (patent for vacuum proff light structure)

Edited April 3, 2016 by AngelLestat

[fredinno]

1 hour ago, AngelLestat said:

Helium has a big drawback, is expensive, this mean that you can not design an airship able to lift a big payload, or reach high altitude without vent lifting gas or had good speed or range.
In my opinion, helium airships are only useful in application where you need extra safety measures, less than 50 ton of payload and short range or altitude variance.

Hydrogen cost 15 times less and can be used as fuel or can be easily produced locally by the same airship using water, this can be also used as ballast, you just need a flying certificate to allow it and a no flammable envelope. But even with all that it reach a point in the payload and altitude variance in which the vacuum airships becomes more cost effective.

Yeah, but Hydrogen has a bad reputation for burning, especially after Heisenberg.

1 hour ago, AngelLestat said:

Avoid the use of lifting gases had many advantages, you can control your buoyancy very easy just pumping air out or allowing air in (recovering part of the pumping energy), if you want variable buoyancy with lifting gases you need the aeroscraft method, in which many internal pressure envelope are used to compress the helium with another envelope that is filled with external air, this increase considerable the total surface envelope needed.

And you can't do that on a Helium balloon by pumping Helium in and out into a tank inside the airship?
 

I just feel Vacuum Airships are not being made since there isn't really much demand for airships compared to airplanes, anyways.

[kerbiloid]

No need to collapse under the air pressure.

http://www.rusring.net/~levin/levin3d/dz.htm

(Just info: the first line is a disclaimer about "all rights reserved, no usage of the artworks without author's permission.")

 

 

 

Edited April 3, 2016 by kerbiloid

[AngelLestat]

13 hours ago, fredinno said:

Yeah, but Hydrogen has a bad reputation for burning, especially after Heisenberg.

The bad reputation comes from a time where the best material to seal the hydrogen bags was cattle intestines or cotton with gelatine and the external envelope was easily flamable.
In those times you did not have any hydrogen sensor, you did not have weather forecast, the pilots needed to use their eyes to dodge storms and zeppelins cruise altitude was 900m  (you get the worst of the storm at that altitude).
That in conjunction with many other drawbacks in design and technology that those airships had (but an incredible advance for that time 1915) is why they disappear for a long time.
But now they will go back, it will take a time to remove the fear to hydrogen airships, but eventually in few years they will go back. 

13 hours ago, fredinno said:

And you can't do that on a Helium balloon by pumping Helium in and out into a tank inside the airship?

At 10000m you had 0.25 bar of pressure, if you let expand so much the helium you need to vent it or you explote. The aeroscraft with the variance buoyancy system can only reach 3700m as maximun altitude, this is only achieved using aerodynamic lift, just with helium would reach no more than 2000m without venting.
The benefits of using hydrogen instead helium in the altitude, range, payload or speed is not so easy to understand just taking the little difference in lift from hydrogen and helium.
But this page explain all the differences very well:
http://www.airships.net/helium-hydrogen-airships
Helium reduce your payload to half as one of the drawbacks.

13 hours ago, fredinno said:

I just feel Vacuum Airships are not being made since there isn't really much demand for airships compared to airplanes, anyways.

But that is starting to change, the Airlander 10T is already made and receiving purchase orders, the next will be the Airlander 50T, we have also the Lockheed Martin P-791 of 18T which is close to finish and already had a purchase orders of  24 of them, it will follow with a 60T version and a future 500T version.  Then we have the aeroscraft which commercial vehicle is already in the final steps of design, it will be flying in 5 years with a fleet of 6 of 66Tons and 24 of 250Tons, 
So is not just time yet to build a vacuum airship but for sure in 10 years we may see some of them, but they need to be bigger to have sense.

7 hours ago, kerbiloid said:

No need to collapse under the air pressure.

http://www.rusring.net/~levin/levin3d/dz.htm

(Just info: the first line is a disclaimer about "all rights reserved, no usage of the artworks without author's permission.")

I love the draws, thanks for the link, I like the old fashion design, with a clearly steampunk style.
But it should be bigger than that to have sense, more in that time with those materials.
In the links I provide it is mention many different ways to achieve vacuum proff light structures, one is with a double layer of fabric very close one of the other that are also joint between many points, if you inject air at 2 bar between those layers, it will be enough to provide the structure and allow a vacuum inside. 

[fredinno]

9 hours ago, AngelLestat said:

But now they will go back, it will take a time to remove the fear to hydrogen airships, but eventually in few years they will go back. 

Good luck

9 hours ago, AngelLestat said:

At 10000m you had 0.25 bar of pressure, if you let expand so much the helium you need to vent it or you explote. The aeroscraft with the variance buoyancy system can only reach 3700m as maximun altitude, this is only achieved using aerodynamic lift, just with helium would reach no more than 2000m without venting.
The benefits of using hydrogen instead helium in the altitude, range, payload or speed is not so easy to understand just taking the little difference in lift from hydrogen and helium.
But this page explain all the differences very well:
http://www.airships.net/helium-hydrogen-airships
Helium reduce your payload to half as one of the drawbacks.

Yes, but hydrogen is flammable, so you need to be extra cautious your flight does not end early (and I know how hydrogen burning on an airship allows for a slow descent, but it's still more risky than Helium. I also don't see how this has anything to do with what I said in the quote. You can change buoyancy by pushing lifting gas in and out of storage tanks into the airship, right?

9 hours ago, AngelLestat said:

But that is starting to change, the Airlander 10T is already made and receiving purchase orders, the next will be the Airlander 50T, we have also the Lockheed Martin P-791 of 18T which is close to finish and already had a purchase orders of  24 of them, it will follow with a 60T version and a future 500T version.  Then we have the aeroscraft which commercial vehicle is already in the final steps of design, it will be flying in 5 years with a fleet of 6 of 66Tons and 24 of 250Tons, 
So is not just time yet to build a vacuum airship but for sure in 10 years we may see some of them, but they need to be bigger to have sense.

There has always been demand for Airships. You haven't shown me that the demand for airships are increasing, only that it is there.

18 hours ago, kerbiloid said:

No need to collapse under the air pressure.

http://www.rusring.net/~levin/levin3d/dz.htm

(Just info: the first line is a disclaimer about "all rights reserved, no usage of the artworks without author's permission.")

 

 

 

Yeah, and that pretty much does to show that vacuum airships are going to have a lot of their mass fraction removed. Also, that looks very un-aerodynamic, and thus uses more fuel.

[AngelLestat]

19 hours ago, fredinno said:

Yes, but hydrogen is flammable, so you need to be extra cautious your flight does not end early (and I know how hydrogen burning on an airship allows for a slow descent, but it's still more risky than Helium. I also don't see how this has anything to do with what I said in the quote. You can change buoyancy by pushing lifting gas in and out of storage tanks into the airship, right?

No, is not just the benefit of use hydrogen as fuel, read the link of hydrogen vs helium. You get aerodynamic benefit, cost, ballast, fuel, altitude, range, etc.
That is why if we measure just one of those characteristics keeping the other constant, you get less than half of performance with helium measuring that particular characteristic, like payload, or less than half in range, less than half in altitude, cost, etc. 

The extra risk is negligible today, more when you had extra benefits for storm avoidance with hydrogen, if you have solar panels you can even make your own fuel in any place you are. 
I can bet you that is possible to fire all kind of weapons or missiles or even detonate C4 in the envelope, that it would not make the hydrogen explode, even if it has holes already, and it will be possible to go back to surface safe.
We do a lot of activities that are a bit risky than some alternatives, but if the risk is still low and you get a lot of benefits you do it anyway. An airplane for example can not deal with any of those threats mentioned. 

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There has always been demand for Airships. You haven't shown me that the demand for airships are increasing, only that it is there.

Not sure what you mean??  you said that vacuum airships are not being made because there is no much demand for airships vs airplanes..
But the real answer is that you need to start from small scale (10 tons, 18 tons, 50 tons, 60t, 66T, 250t, 500T, 1000T, 2000T, 4000T, 8000T), and small scale (10 tons to 60) has sense to start with helium up to 500T max, then from that point hydrogen will be the next step with airships bigger than 66T up to 8000T, and vacuum airships starts to become interesting just from 2000T.  So demands has nothing to do with this.

For example this is one of the orders that Lookeheed martin already receive:
http://www.star-telegram.com/news/business/article68993597.html
If there was no orders before and now there are, that is a demand increase.  There was an study made that said they can sell 500 airships in a decade studying the current demands for this first airship models (10, 18 and 50T).

Of course everyone would be happy to transport stuff or travel in a 8000T airship, the demand is there, but you need to start from below. If you made one that big now, and you take 5 to 10 extra years to get the certifacate to sell it, you lose a lot of money and you become exposed to other industries to copy your design and get their certification few days later or even faster depending country policies.

An airplane becomes harder and less useful after certain scale, the airships instead are more cost effective each time you increase the scale.
 

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Yeah, and that pretty much does to show that vacuum airships are going to have a lot of their mass fraction removed. Also, that looks very un-aerodynamic, and thus uses more fuel.

No, as I said over and over.. it depends on the scale, it reach the point where a vacuum airship (that of course has variable bouyancy) gets less payload penalty than a helium airship. Or even an hydrogen airship increasing even more the scale. That design you see there is just a draw of an airship to match the 1900 period as we can see for the lady dress and materials.
That is not the only kind of design for vacuum airships, read the first pdf I post. 

Edited April 4, 2016 by AngelLestat
english corrections

[sevenperforce]

On 4/3/2016 at 9:58 PM, fredinno said:

Yeah, but Hydrogen has a bad reputation for burning, especially after Heisenberg.

Yeah, I know, right? It really sucks when you can know the location of your airship but not its velocity, or the velocity but not the location.

If we ever figured out lightweight forcefields then building a vacuum airship would be a snap.

[SSR Kermit]

23 minutes ago, sevenperforce said:

If we ever figured out lightweight forcefields then building a vacuum airship would be a snap.

Although, why build an airship if you can just levitate the vessel with a forcefield?

[sevenperforce]

1 minute ago, SSR Kermit said:

Although, why build an airship if you can just levitate the vessel with a forcefield?

Open-cell vs closed-cell forcefield problem.

[SSR Kermit]

1 minute ago, sevenperforce said:

Open-cell vs closed-cell forcefield problem.

My first reaction was "As long as our fringe physics obeys conservation laws, any closed cell could generate thrust", but that's kind of the standard statement I suppose.

Thinking about it, the force in question could be the colour force and the barrier like properties come from residual strong force. That would explain why they let EM waves (light) through, but not ordinary matter. That's not how they work in most sci-fi (eg Star Trek, where they are said to be 'EM particle fields tuned to certain frequencies' ), but it's kind-of a neat idea.

 

[fredinno]

3 hours ago, AngelLestat said:

I can bet you that is possible to fire all kind of weapons or missiles or even detonate C4 in the envelope, that it would not make the hydrogen explode, even if it has holes already, and it will be possible to go back to surface safe.

Except if the hydrogen leaks into the atmosphere, in which case it will eventually ignite with the oxygen in the air.

3 hours ago, AngelLestat said:

We do a lot of activities that are a bit risky than some alternatives, but if the risk is still low and you get a lot of benefits you do it anyway. An airplane for example can not deal with any of those threats mentioned. 

Sure, we do more risky things. Is it worth it? How much do you need to carry people and cargo over a few weeks across the globe?

I can see this working for remote areas. But if this can compete seriously vs sea+ rail is a serious question. Time will tell.

 

Edited April 5, 2016 by fredinno

[AngelLestat]

12 hours ago, fredinno said:

Except if the hydrogen leaks into the atmosphere, in which case it will eventually ignite with the oxygen in the air.

It will ignite with the oxygen in the air..  There is no issue there meanwhile you have a non flammable envelope.  The hole you had or leak will not spread, you will have a little flame or big flame in case the hole was caused by C4, but even with a big hole, at equal pressure with a big ship, it will take a lot of time to burn or leak enough hydrogen. The same that you will not die igniting your stove.
You can control with pressure (because you also had extra hydrogen in pressurized tanks to be used as fuel) to always had higher pressure inside than outside.
 

I also forget to answer you a previous question you made.   (why you can not rise more altitude compressing the helium).
The aeroscraft design use big and light pressure envelopes (1) which compress the helium at low pressure (few bars).  This require low energy and is a fast process, you can had special tanks to allow 700 Bar as the fuel cells cars, but you lose more energy in the compression and it takes more time to compress.  Of course your airship no only is worry in rise or go down, you need to be energy efficient and be manoeuvrable.
(2) external envelope to enclose the helium
(3) ballonets that are filled with external air.

PDF

The other kind of hybrid airships does not even compress the helium, so they depend only in aerodynamic lift and ballonets to reach a medium altitude without vent helium.

Quote

Sure, we do more risky things. Is it worth it? How much do you need to carry people and cargo over a few weeks across the globe?

I can see this working for remote areas. But if this can compete seriously vs sea+ rail is a serious question. Time will tell.

Airships are fuel efficient, they can land in any relative flat location, water, ice, a rough field, etc. 
They can load and unload cargo without external infrastructure, they are faster than ships, trucks and even trains.  They travel from point to point in straight line.
Of course this is not enough to remplace other kind of transport vehicles, but for sure has its place, its niche is no small at all. 

Edited April 5, 2016 by AngelLestat

[sevenperforce]

15 hours ago, SSR Kermit said:

My first reaction was "As long as our fringe physics obeys conservation laws, any closed cell could generate thrust", but that's kind of the standard statement I suppose.

Thinking about it, the force in question could be the colour force and the barrier like properties come from residual strong force. That would explain why they let EM waves (light) through, but not ordinary matter. That's not how they work in most sci-fi (eg Star Trek, where they are said to be 'EM particle fields tuned to certain frequencies' ), but it's kind-of a neat idea.

 

Of course, the kinds of advances which we would need to make in order to produce force fields would almost certainly be preceded by the development of macroscopic graphene structures and other materials capable of supporting a vacuum airship under tension.

Wrap a geodesic sphere in fabric made from woven carbon nanotubes and you will have no difficulty pumping the air out of it entirely.

[fredinno]

18 hours ago, AngelLestat said:

There is no issue there meanwhile you have a non flammable envelope.

No, that increases cost. If you don't need one (as for helium) you can reduce cost.

8 hours ago, sevenperforce said:

Wrap a geodesic sphere in fabric made from woven carbon nanotubes and you will have no difficulty pumping the air out of it entirely.

...and where do you get the development money for that? Is demand high enough?

 

18 hours ago, AngelLestat said:

The hole you had or leak will not spread, you will have a little flame or big flame in case the hole was caused by C4, but even with a big hole, at equal pressure with a big ship, it will take a lot of time to burn or leak enough hydrogen.

Explain Heisenburg.

18 hours ago, AngelLestat said:

, they can land in any relative flat location, water, ice, a rough field, etc. 

So can helicopters, which is probably the only thing this will replace on the mainstream (civilian uses, of course).

18 hours ago, AngelLestat said:

Airships are fuel efficient

History has shown us economics are more important. Considering how slow airships go in comparison to planes, and that time=money....

I don't think they can compete against trucks either because of how big the landing pads would need to be in comparison to a parking lot.

18 hours ago, AngelLestat said:

They travel from point to point in straight line.

That's an advantage? Talk about grasping at straws.

18 hours ago, AngelLestat said:

They can load and unload cargo without external infrastructure, they are faster than ships, trucks and even trains.

Sure. So can trucks, and trains, if you wanted too. Hell, you could do the same with ships. Only we don't, because we now use containers.

I can see what the oil companies are thinking, buying airships, but I think the cost to make it work is too high, and bribing to build pipelines is probably more effective and efficient.

[AngelLestat]

2 hours ago, fredinno said:

No, that increases cost. If you don't need one (as for helium) you can reduce cost.

Helium increase the cost, due its high cost and its drawbacks.
At low scale may have sense as I said.. But if you increase the scale, surface cost becomes negligible, also non flammable materials are not very expensive either.

2 hours ago, fredinno said:

Explain Heisenburg.

Ok, joke aside, the Hindenburg burn almost in the instant just because its envelope was flammable, there is no other explanation for that, if your envelope is non flammable your original orifice or leak can not spread, never. So the amount of hydrogen leaks remains the same, you will have a flame over all your trip (in case the wind did not suffocate the flame first), but it does not matter if you have a flame, it can not spread and never will blow up, because the hydrogen is mixing with the oxygen just in that point. One side has 100% hydrogen the other 25% oxygen. 

2 hours ago, fredinno said:

So can helicopters, which is probably the only thing this will replace on the mainstream (civilian uses, of course).
History has shown us economics are more important. Considering how slow airships go in comparison to planes, and that time=money....
I don't think they can compete against trucks either because of how big the landing pads would need to be in comparison to a parking lot.
That's an advantage? Talk about grasping at straws.
Sure. So can trucks, and trains, if you wanted too. Hell, you could do the same with ships. Only we don't, because we now use containers.
I can see what the oil companies are thinking, buying airships, but I think the cost to make it work is too high, and bribing to build pipelines is probably more effective and efficient.

I made my case here:

The fact that even with low scale helium airships a lot of companies are very interested to buy them, and there are about 6 companies in the world making these new airships a reality (with many country interested like china, russia, europe community, chile, argentina, USA, Canada), the Europe community is already planning all the logistic to include these new airships.
By the way, you dont need landing pads, that is the main point of these airships, they can land in almost any place, they can even unload payload without land.
The time you take to load your trucks, transport that to a cargoship or to the airport, then unload that in a truck and carry that to destination taking into account traffic and other delays in each process, it makes airships very practical and cheap.

[sevenperforce]

4 hours ago, fredinno said:

 

...where do you get the development money for [carbon nanotube weave]? Is demand high enough?

I'm not suggesting we develop carbon nanotube weave merely to build vacuum airships. Carbon nanotube weave will be developed for numerous applications as soon as it can be. Everybody needs that stuff. 

5 hours ago, fredinno said:

Explain Heisenburg.

Okay, so on certain scales, it is not possible to determine the position and momentum of a particle simultaneously. The uncertainty in the product of position and momentum is approximately equal to the Planck constant. This is because particles are actually wave functions and exist across all space with a defined expectation value. 

Or were you talking about Walter White?