Of missiles, and hydrogen...
Thread Starter
Join Date: Dec 2008
Location: See that little island just above France? Yeah, there...
Age: 37
Posts: 168
Likes: 0
Received 0 Likes
on
0 Posts
Of missiles, and hydrogen...
I've been mulling this over, and decided to post a question, or rather a statement on here to see if any more intelligent/learned ppruners can answer me...
We all know that soon, the worlds supply of oil will run out, or at least become so expensive to get out of the earth that drilling becomes pointless. At this point, we must stop using Aviation Fuel.
So, the fuel of the future as far as I can tell, will be Hydrogen. Clean, easy to find etc etc, all very good. However, although it can be used to fuel aircraft engines, it has a major problem, in that it takes up around 3 times as much space to store enough to go, say 100 miles, as it would to store enough petrolium based fuel to go the same distance.
In aircraft this means larger fuel tanks, whereas in rockets this means, surely having to make a missile larger to gain the same range.
For example, a hydrogen propelled short range missile akin to a AIM9 would have to be more the size of an AIM54 Pheonix... with all the disadvantages of weight.
My question to the engineers knocking around here is simply... to what extent am I correct, and if I AM correct (doubtfully) what other options are there?
Note: All information i've been working from is that which is available all over the internet. As you can probably tell this is not from experience, I am simply curious.
We all know that soon, the worlds supply of oil will run out, or at least become so expensive to get out of the earth that drilling becomes pointless. At this point, we must stop using Aviation Fuel.
So, the fuel of the future as far as I can tell, will be Hydrogen. Clean, easy to find etc etc, all very good. However, although it can be used to fuel aircraft engines, it has a major problem, in that it takes up around 3 times as much space to store enough to go, say 100 miles, as it would to store enough petrolium based fuel to go the same distance.
In aircraft this means larger fuel tanks, whereas in rockets this means, surely having to make a missile larger to gain the same range.
For example, a hydrogen propelled short range missile akin to a AIM9 would have to be more the size of an AIM54 Pheonix... with all the disadvantages of weight.
My question to the engineers knocking around here is simply... to what extent am I correct, and if I AM correct (doubtfully) what other options are there?
Note: All information i've been working from is that which is available all over the internet. As you can probably tell this is not from experience, I am simply curious.
Join Date: Apr 2008
Location: Well, Lincolnshire
Age: 69
Posts: 1,101
Likes: 0
Received 0 Likes
on
0 Posts
Hmm, just a thought then.
If aviation fuel runs out, it will run out for everyone.
So, if no-one is flying, why would you need missiles to shoot at things that aren't flying anyway?
It's not an answer, Yeoman, but the cricket's rained off, she who must be obeyed is out, my pals and I have started on the red wine early.......
And that was the only (admittedly non-sensible) response we could come up with.
All being well, a few grown-up's will come up with some better responses.
Best regards
If aviation fuel runs out, it will run out for everyone.
So, if no-one is flying, why would you need missiles to shoot at things that aren't flying anyway?
It's not an answer, Yeoman, but the cricket's rained off, she who must be obeyed is out, my pals and I have started on the red wine early.......
And that was the only (admittedly non-sensible) response we could come up with.
All being well, a few grown-up's will come up with some better responses.
Best regards
Join Date: Mar 2006
Location: West Sussex
Posts: 1,771
Likes: 0
Received 0 Likes
on
0 Posts
I'm sure you're right about Hydrogen being a future fuel, unless we get nuclear fusion first ( unlikely ) - the Holy Grail is of course to get water to separate into its' H2O components, some say they've managed this in a small way by electolysis...
The other point not mentioned is Hydrogen is rather bad news in gaseous state ( - i.e, as it goes into an engine under pressure ? ) if there's a cock-up of any kind, see ' Hindenberg ' for details !
The other point not mentioned is Hydrogen is rather bad news in gaseous state ( - i.e, as it goes into an engine under pressure ? ) if there's a cock-up of any kind, see ' Hindenberg ' for details !
Thread Starter
Join Date: Dec 2008
Location: See that little island just above France? Yeah, there...
Age: 37
Posts: 168
Likes: 0
Received 0 Likes
on
0 Posts
Sterling effort chaps so farRather the point is that aircraft can still fly on hydrogen - they just need bigger fuel tanks for similar range so aircraft will be flying, hence a need to shoot some of the naughty ones down.
Virtually all missiles in the classes you're talking about use solid rocket motors, so lack of aviation fuel would not be a problem (ignoring the question of powering any launch platform!). Only the really long-range cruise missiles use turbine engines and therefore require kerosene; the quantity of kerosene in those missiles is relatively small and I'm sure they could keep finding enough of it in future.
Ecce Homo! Loquitur...
At this point, we must stop using Aviation Fuel.
1. AAM and the like don't use AVGAS or AVTUR now, neither will they when cheap oil runs out. Solid rocket fuel will continue to be made from alternate organic sources.
2. The same holds true for aircraft. AVTUR does not have to be made from oil or coal, alternate sources such as tar sands, bio-fuel crops or other hydrocarbon sources can be used to manufacture an AVTUR equivalent. It's not a new technology, it just makes it a bit more expensive.
Join Date: Jun 2007
Location: Hampshire
Posts: 137
Likes: 0
Received 0 Likes
on
0 Posts
You've nailed the basic problem with hydrogen, which is why other sources are being actively looked at, like bio-diesels from algae which Boeing were looking at.
Using algae to produce fuel gives you a pretty limitless resource (given adequate area for farming vs food), but at present the fuels produced suffer from high viscosity at low temperatures, so may well need some further blending to produce something suitable for aircraft use.
Whatever comes in the near future is going to need to be pretty similar to avtur for ease of use in existing aircraft and supply infrastructure (which would be massive for hydrogen).
Presuming that no way of storing electric charge well suddenly emerges and solar and ground based laser power aren't sufficient, I'd place my money on something you can grow.
Using algae to produce fuel gives you a pretty limitless resource (given adequate area for farming vs food), but at present the fuels produced suffer from high viscosity at low temperatures, so may well need some further blending to produce something suitable for aircraft use.
Whatever comes in the near future is going to need to be pretty similar to avtur for ease of use in existing aircraft and supply infrastructure (which would be massive for hydrogen).
Presuming that no way of storing electric charge well suddenly emerges and solar and ground based laser power aren't sufficient, I'd place my money on something you can grow.
Yes, Him
Join Date: Aug 1999
Location: West Sussex, UK
Posts: 2,689
Likes: 0
Received 0 Likes
on
0 Posts
although it can be used to fuel aircraft engines, it has a major problem, in that it takes up around 3 times as much space to store enough to go, say 100 miles, as it would to store enough petrolium based fuel to go the same distance.
Join Date: Apr 2008
Location: Well, Lincolnshire
Age: 69
Posts: 1,101
Likes: 0
Received 0 Likes
on
0 Posts
Ah, I knew the grown-up's would come along.
You've certainly given this bunch of geriatrics (starved of cricket) something to debate in this corner of North Yorkshire.
I'll pull a few more corks to 'fuel' the exchanges.
You've certainly given this bunch of geriatrics (starved of cricket) something to debate in this corner of North Yorkshire.
I'll pull a few more corks to 'fuel' the exchanges.
Thread Starter
Join Date: Dec 2008
Location: See that little island just above France? Yeah, there...
Age: 37
Posts: 168
Likes: 0
Received 0 Likes
on
0 Posts
I thought Pprune was starved of debate recently taxydual 
It's good to know about this, it's always been a question of mine. Maybe I had in mind a return of prop planes and gun dogfights
Keep 'em coming chaps.
It's good to know about this, it's always been a question of mine. Maybe I had in mind a return of prop planes and gun dogfights
Keep 'em coming chaps.
Join Date: Jun 2007
Location: Wilts
Posts: 109
Likes: 0
Received 0 Likes
on
0 Posts
Coal?
A bit of back to the future here, but according to this article the US are looking at coal, something the Germans had a look at in the last days of WW2. Thanks to Mrs T we still have lots of the stuff!
8-15 etc:
"Are you quite mad, Captain? I'm telling you the noo, you'll not get another pound of steam out of these boilers, d'you ken?".
Sorry, Hat, Coat, P45....
US are looking at coal
Sorry, Hat, Coat, P45....
Join Date: Mar 2006
Location: West Sussex
Posts: 1,771
Likes: 0
Received 0 Likes
on
0 Posts
Gainesy,
I'm trying hard not be a smartarse but have succumbed - surely semi-rigid airships don't inflate or shrink via Hydrogen ?
I'm reliably informed by someone who would know ( senior Rolls Royce aero-engines man ) that for example the Speys on the UK Phantom were cleared to run on coal dust.
Not sure what form the coal dust was in, as we had to break off our conversation.
If wearing a ' green ' badge, one must comment that all fossil fuels will run out sometime, the only question is whether coal or similar gives enough breathing space before a more intelligent power source comes along - for the medium term, " fuel you can grow " sounds about right to me.
As for Hydrogen, must have potential but you go first, and keep the ' no smoking ' sign on, also steer clear of static / lightning !
I'm trying hard not be a smartarse but have succumbed - surely semi-rigid airships don't inflate or shrink via Hydrogen ?
I'm reliably informed by someone who would know ( senior Rolls Royce aero-engines man ) that for example the Speys on the UK Phantom were cleared to run on coal dust.
Not sure what form the coal dust was in, as we had to break off our conversation.
If wearing a ' green ' badge, one must comment that all fossil fuels will run out sometime, the only question is whether coal or similar gives enough breathing space before a more intelligent power source comes along - for the medium term, " fuel you can grow " sounds about right to me.
As for Hydrogen, must have potential but you go first, and keep the ' no smoking ' sign on, also steer clear of static / lightning !
Join Date: Jul 2000
Location: Back from the sandpit
Age: 63
Posts: 492
Likes: 0
Received 0 Likes
on
0 Posts
As Hydrogen is many times lighter than Avtur, and even lighter than air, it won't matter if it takes up 3 times as much space, as being lighter than air it will assist in the lift of the aircraft and you will save on the weight of the Avtur.
Hat & Coat on, heading for the door
Hat & Coat on, heading for the door
Join Date: Mar 2006
Location: West Sussex
Posts: 1,771
Likes: 0
Received 0 Likes
on
0 Posts
Isn't that only if it's in gaseous, not liquid form ?
No idea how the two liguids compare weight wise, but I have a nasty feeling Hydrogen will end up heavier, allowing for containment conditions.
No idea how the two liguids compare weight wise, but I have a nasty feeling Hydrogen will end up heavier, allowing for containment conditions.
