Amusing Hydrogen tankage thoughts

[atpollard]

Does it?

I was not implying that I was the THOUGHT POLICE.

I was merely observing that your OP figure is a single data point.

• A tank with 1/100 the volume of LH2 will have exactly 1/100 the volume of fuel but a different value for kg of tank per cubic meter of LH2 [and a tank of exactly 1/100 the volume of Tank plus fuel will have a different volume of LH2 and still have a different measure of kg of tank per cubic meter of tank and fuel.] The thickness of the insulation will be constant, but the surface area and volume inside the tank will change, so the ratio of tank mass to volume will change with size.
• If you build a tank 100x larger than your design, the data point will change again.

So the only CONSTANT value for a dTon is based on internal fuel (which maintains a constant ratio of volume to mass ... density).

 

[Spinward Scout]

Ships carrying liquid cargoes have them too; I would imagine that aircraft with large fuel tanks would have them as well.

I don't think you can avoid it. Unless you split up the tanks into a bunch of smaller tanks. Which might make sense from a combat point of view. If you spill one small tank, it's better than getting a hole in a big tank.

 

[Rupert]

Still would be prohibitive to go gaseous state as now you have to push/jump all that hull that carries and protects the fuel.

Playing round with various design systems that do care about mass as well as volume (FF&S and GURPS Vehicles, mainly) has shown me that even with liguid hydrogen the low density can be a problem - despite its high energy density it can be worse than hydrocarbons because of the extra volume liquid hydrogen tanks require, and the bigger and heavier hulls required to hold those tanks, and the bigger engines, etc. required to move them, etc. - if a design is tight this can snowball quite seriously.

 

[Spinward Scout]

Try 1 : 848 (according to the US Department of Energy) on for size and then ask yourself if the refrigeration equipment is "worth it" so you can have SMALLER hydrogen tanks. Wikipedia lists the expansion ratio at 1:850.

Wow! What a difference. So what happens when you get a fuel hit in combat? I've never looked that up.

L-Hyd flowing all over the ship is dangerous. Your VACC Suit isn't going to do much if a wave of liquid hydrogen washes over you. Although it might evaporate pretty fast.

 

[kilemall]

Wow! What a difference. So what happens when you get a fuel hit in combat? I've never looked that up.

L-Hyd flowing all over the ship is dangerous. Your VACC Suit isn't going to do much if a wave of liquid hydrogen washes over you. Although it might evaporate pretty fast.

Doesn’t really do anything per tables. Of course the fire/explosion risk should be mitigated by going to vacuum precautionary.

Ever since a deep dive into HG and the radioactive shielding property of LH, I’ve assumed the bulk of tanks wrap around near the surface and blow out to space when damaged. I’ve also included them into rad hits, with the effect being fuel going unrefined.

 

[Spinward Flow]

Wow! What a difference.

Hence why I was so ... incredulous ... that you even proffered the option.

So what happens when you get a fuel hit in combat? I've never looked that up.

You get a surface explosion hull rupture and a portion of your fuel load (minimum 10 tons) gets vented out into space, where it is lost (just like with most other forms of explosive decompression).

I was under the impression that this type of result was self-explanatory.

 

[Ekofisk]

So what happens when you get a fuel hit in combat?

This?
Consider this another vote for precautionary depressurization.

 

[Spinward Scout]

This?
Consider this another vote for precautionary depressurization.

I like Spinward Flow's explanation. Not dealing with steam and flame would be much better.

Hence why I was so ... incredulous ... that you even proffered the option.

You get a surface explosion hull rupture and a portion of your fuel load (minimum 10 tons) gets vented out into space, where it is lost (just like with most other forms of explosive decompression).

I was under the impression that this type of result was self-explanatory.

Yeah, that's what I get for posting around 4am.

 

[Ekofisk]

Hydrogen explosions here. Nice one starts at 4:48 in.
The Battlerider game has a critical that covers this:
"Ship Explodes: Liquid hydrogen and oxygen escape from shattered storage tanks, combine in the interior spaces of the ship, and explode, setting off a chain reaction with the ship's ordnance and power plant. The vessel is completely destroyed. Replace the ship counter with a White Out-2 marker."

Has the makings of "bad day" written all over it.

 

[Condottiere]

Armoured bulkhead internally, blow out panels externally.

 

[Spinward Scout]

I was not implying that I was the THOUGHT POLICE.

Zhodani spy?

 

[Condottiere]

Media influencer.

 

[atpollard]

Zhodani spy?

Thoughtcrime
The offense of thinking in ways not approved by the ruling party. In the official language of Newspeak, the word "crimethink" describes the intellectual actions of someone who holds unacceptable thoughts. The Party punishes thoughtcrime, and the thought police are tasked with catching those who commit it.

- "Nineteen Eighty-Four" by George Orwell

 

[BlackBat242]

Thoughtcrime
The offense of thinking in ways not approved by the ruling party. In the official language of Newspeak, the word "crimethink" describes the intellectual actions of someone who holds unacceptable thoughts. The Party punishes thoughtcrime, and the thought police are tasked with catching those who commit it.

- "Nineteen Eighty-Four" by George Orwell

Sounds like the Zhos to me.

 

[aramis]

Sounds like the Zhos to me.

Except that the Zhos consider the criminal impulse a mental illness or defect, one that they caj usually fix.
And when found, they do fix it.
Kind of a dark utopia...

 

[mike wightman]

Better than the alternative surely - a life time of incarceration or being executed by the state.

 

[aramis]

Better than the alternative surely - a life time of incarceration or being executed by the state.

For some, the idea of one's mind being adjusted by the state is scarier than life in a 10' cube... And for many, execution for wrongthink is not worse than being adjusted.

"I may die, but at least I shall die free!"

 

[mike wightman]

Then give them the choice:
lifetime in the spice mines
execution
mental health treatment