Saving Ash from a Volcanic Eruption: A Geologist's Perspective

[Frame Dragger]

does anyone know what causes volcanic lightning? seems like it could be various things (change in pressure, particles in the air, moisture, magnetic materials, etc)

Friction between particulate matter. Think of an ash cloud as a BIG carpet, with it's own slippers.

 

[pivot]

I feel like, then, all volcanoes would have lightning, but that isn't the case.

 

[Frame Dragger]

I feel like, then, all volcanoes would have lightning, but that isn't the case.

All volcanoes don't produce large, energetic explosions, or ash plumes. If we're just talking about a pyroclastic flow (which not all volcanoes have), with little or no plume, then:

1.) There may be a lot of moisture which would inhibit the process, but mostly
2.) The cloud is mostly grounded already.

 

[DaveC426913]

I feel like, then, all volcanoes would have lightning, but that isn't the case.

By that logic all rain clouds should have lightning too. As it is though, only the really big ones do.

 

[mgb_phys]

I think this event shows it's time to think of a tunnel again.

http://homepage.ntlworld.com/forgottenfutures/express/express.htm

 

[Frame Dragger]

Holy ****...

http://www.businessandfinance.ie/cat_news_detail.jsp?itemID=1479

BA should be shot in the knees for taking passengers for such a "ride". The bloody fools should have taken their fleet home a few hours later and avoided this. 6K passengers are going to be deeply pissed.

 

[cristo]

Holy ****...

http://www.businessandfinance.ie/cat_news_detail.jsp?itemID=1479

BA should be shot in the knees for taking passengers for such a "ride". The bloody fools should have taken their fleet home a few hours later and avoided this. 6K passengers are going to be deeply pissed.

BA decided to play hardball with NATS by launching some of their long haul flights towards heathrow, an airport that, when the flights will have taken off, BA would have been told is closed until at least 0100 on Weds. This resulted in some planes being diverted to Ireland, some being held in holding patterns for hours.

It seems that BA has won, since NATS has just announced that airspace will be opening in phases from 2200.

 

[Count Iblis]

A plane from Toronto was diverted to Newcastle. So, you'll have a lot of passengers finding themselves in the Middle of Nowhere

 

[cristo]

A plane from Toronto was diverted to Newcastle. So, you'll have a lot of passengers finding themselves in the Middle of Nowhere

Newcastle isn't such a bad place to divert to (and isn't too bad a city.. watch it, Kurdt will get you ) as there's a direct rail link. Shannon, on the other hand, is on a different island!

 

[Frame Dragger]

Newcastle isn't such a bad place to divert to (and isn't too bad a city.. watch it, Kurdt will get you ) as there's a direct rail link. Shannon, on the other hand, is on a different island!

Hmmm, they designated these flight numbers as landing in Heathrow and Gatwick... I maintain there are going to be some seriously ticked passengers. Granted, it's cheaper than leaving planes grounded, but if they were not honest about the destination... damn.

Then there are the people stuck in Amsterdam... and they're complaining! The Dutch are sending lovely women in traditional dress to entertain people in a city with legal marijuana. As Force Majeure goes... not too bad an outcome.

This is all the same BS as per usual... getting people on the plane, instead of warning them of certain delays... etc...
I'll just say this... I'm ever stuck on the tarmac for 4+ hours, I'm getting up to take a little walk down the aisle, and blow the first emergency hatch or door I find.

 

[mheslep]

Occurs to me that that this ash problem is another reason for aviation to pursue electric ducted fan powered aviation, along with an appropriate energy source. (https://www.physicsforums.com/showpost.php?p=2292842&postcount=14"). The high temperatures inside current turbine jet engines that melt ash silicas are absent in ducted fans. In addition to fans, find a material tough enough for a windscreen and the Friendly Skies will be unlikely, or at least much less likely, to be interrupted by the next mons flammas eructans.

 

[turbo]

Occurs to me that that this ash problem is another reason for aviation to pursue electric ducted fan powered aviation, along with an appropriate energy source. (https://www.physicsforums.com/showpost.php?p=2292842&postcount=14"). The high temperatures inside current turbine jet engines that melt ash silicas are absent in ducted fans. In addition to fans, find a material tough enough for a windscreen and the Friendly Skies will be unlikely, or at least much less likely, to be interrupted by the next mons flammas eructans.

How do you power it, though and allow efficient operation? Right now, fossil-fuel-driven turbines are the big game in town and every step in conversion, transmission, storage, etc, steals from the efficiencies.

 

[Frame Dragger]

I'm guessing we'll be riding RAMjets before we find safe energy storage of the density needed for that kind of ducted fan as propulsion.

This is really a big problem for the military... as civilians we have rail technology we COULD implement if we chose, that would be fairly effecient.

 

[mheslep]

How do you power it, though and allow efficient operation? Right now, fossil-fuel-driven turbines are the big game in town and every step in conversion, transmission, storage, etc, steals from the efficiencies.

The fan itself would be ~98% efficient. The energy source is another hard problem*, but some possibilities include fuel cells run from hydrogen or natural gas, etc, or a normal jet fuel powered turbine electric generator + batteries which are used at cruise.

*Edit: If a fuel cell or electric turbine generator is used they will suffer the usual efficiencies and losses.

 

[mheslep]

I'm guessing we'll be riding RAMjets before we find safe energy storage of the density needed for that kind of ducted fan as propulsion.

How do you take off and land with a RAMjet? Also, I doubt RAMjets solve the ash problem. Though the moving parts are gone, the high temperatures melting the ash remain, eventually corroding the engine structure.

 

[Frame Dragger]

How do you take off and land with a RAMjet? Also, I doubt RAMjets solve the ash problem. Though the moving parts are gone, the high temperatures melting the ash remain, eventually corroding the engine structure.

You misunderstand... I'm not saying we SHOUlD, I'm saying that I believe that technology is going to be ahead of the kind of energy storage you describe.

As for taking off and landing... um... how about ducted fans or props for ascent and descent? (yes, I get the irony) You'd already be carrying hydrogen, which makes the fuel-cell quite feasible. You also can fly ABOVE the ash cloud at high efficiency, and with no delicate moving parts, removing the glass becomes a much smaller issue. I'm also unclear as to whether glass would actually VITRIFY in a RAMjet... it seems to me that it would remain molten and blow out the um... backside.

 

[mheslep]

You misunderstand... I'm not saying we SHOUlD, I'm saying that I believe that technology is going to be ahead of the kind of energy storage you describe.

Understood. My point is I don't see a path forward for RAMjets given the physics of RAMjets. I do see a way forward for the physics of ducted fans; on balance fans + an energy source appear to be an engineering problem.

As for taking off and landing... um... how about ducted fans or props for ascent and descent? (yes, I get the irony)

Not clear what you mean. Do you mean use RAMjets plus another set of engines to handle the total flight envelope? That's a big aircraft performance hit to payload.

You'd already be carrying hydrogen, which makes the fuel-cell quite feasible. You also can fly ABOVE the ash cloud at high efficiency,

That's a good point - RAMjets make the high altitude possible unlike the turbine.

and with no delicate moving parts, removing the glass becomes a much smaller issue. I'm also unclear as to whether glass would actually VITRIFY in a RAMjet... it seems to me that it would remain molten and blow out the um... backside.

Can't prevent interaction with the containing walls, though I have no idea of the gross effect.

 

[Frame Dragger]

Understood. My point is I don't see a path forward for RAMjets given the physics of RAMjets. I do see a way forward for the physics of ducted fans; on balance fans + an energy source appear to be an engineering problem.

Not clear what you mean. Do you mean use RAMjets plus another set of engines to handle the total flight envelope? That's a big aircraft performance hit to payload.

That's a good point - RAMjets make the high altitude possible unlike the turbine.

Can't prevent interaction with the containing walls, though I have no idea of the gross effect.

Yeah, I have no idea what the end effect would be either. We're talking about MUCH higher sustained temps in a RAMjet than a jet-turbine. That said, FA-18s were being glassed on their engines... and they aren't slouches in the heat department.

As for takeoff and landing, yes, I mean having another set of engines. I can't imagine anything short of a "capture craft" which would be insane, as an alternative. Remember, RAMjets don't NEED to be be carrying huge payloads... that's not realistic anyway. That said, for medical evacuations, organ transplants, and high priority rapid travel it would be VERY useful. In that scenario, reduced payload is offset by the EXTREMELY low price of the fuel, and how rapidly you can turn over a flight.

That... I don't think anyone can reliably predict. That said, energy storage that isn't essentially a bomb is tough to come by. Batteries are not racing ahead, but hindering virtually everything. Maybe super-capacitors could be useful, but not in their current incarnations. As for a hydrogen fuel-cell... you can use them on a sub, but one to power ducted fans for a plane? That's a tough one, and without radical technological breathroughs I see 2 problems:

1.) Hindenberg^2. Jet fuel is flammable, but hydrogen under pressre?! Damn. Same with LNG. This would also be a storage NIGHTMARE on the tarmac in terms of refueling. We would be flying bombs, in a way that current aircraft don't even BEGIN to approach.

2.) If we're talking about liberating hydrogen, there are limited way to do this. Is burning coal for electrolysis really better than jet-fuel? Hydrogen has a long way to go, and at least a RAMjet doesn't need anywhere near the amount a fuel-cell does.

Plus... RAMjets are VERY simple, and I pity the bird who is sucked into one. Roast goose anyone... at mach 3? SCRAMjets are probably bound to be missile/drone only... but RAMjets have a great deal of potential.

Batteries... it always comes down to stupid batteries in some form or another. A breakthrough in energy storage would be magnificent. Look what modern Lithium-Ion-Polymer batteries have done! If we could store energy reliably and safely on a large scale (short of vanadium batteries the size of an elementary school), it would change the world overnight. So much technology is just waiting for more juice... so frusterating.

*shouts at materials engineers at PF* Come on... GET ON IT! We need dilithium crystals post-haste.

 

[Evo]

does anyone know what causes volcanic lightning? seems like it could be various things (change in pressure, particles in the air, moisture, magnetic materials, etc)

Great picture of the lightning.

http://www.swisseduc.ch/stromboli/perm/iceland/eyafallajokull_20100416-en.html?id=3

 

[Frame Dragger]

Great picture of the lightning.

http://www.swisseduc.ch/stromboli/perm/iceland/eyafallajokull_20100416-en.html?id=3

Wow. If I saw that in real life, I would be running with a pantload of poop and shame... my dignity would be absent.

My mother once encountered a Puma in Tikal (truly, the middle of a jungle in Guatamala), and while the experience has been memorable... it also scared the crap out of her. I love lightning, but that, plus volcanic plume + magma = I get why people looked at that and decided to worship the damned things.

 

[mheslep]

1.) Hindenberg^2. Jet fuel is flammable, but hydrogen under pressre?! Damn. Same with LNG. This would also be a storage NIGHTMARE on the tarmac in terms of refueling. We would be flying bombs, in a way that current aircraft don't even BEGIN to approach.

Myths. Hindenberg fire and explosion was due to the coating on the skin, not the H2. H2 has safety https://www.physicsforums.com/showpost.php?p=2592657&postcount=44" compared to hydrocarbon fuels. It's not clear that it is more dangerous than jet fuel.

Back to the mountain of fire.

 

[NeoDevin]

Looks like something out of a sci-fi movie.

 

[mheslep]

Looks like something out of a sci-fi movie.

Yes it does. If this was from Hollywood I would have thought, nah, not believable, they overdid the special effects again.

 

[Frame Dragger]

Myths. Hindenberg fire and explosion was due to the coating on the skin, not the H2. H2 has safety https://www.physicsforums.com/showpost.php?p=2592657&postcount=44" compared to hydrocarbon fuels. It's not clear that it is more dangerous than jet fuel.

Back to the mountain of fire.

Are you talking about the "thermite" proposal for the doping agent? Hell man, even MYTHBUSTERS took that one on. Sure, it may well have contributed to the disaster, but that doesn't make hydroge SAFE. Keep in mind as well, that the hydrogen in a zeppelin isn't under high pressure... if it had been the doping wouldn't have mattered, it would have been confetti.

Jet fuel really isn't that dangerous... it requires the proper mixture with oxygen to "go boom". LNG is pretty well studied, and a blast from a propane tank vs. a similar vessel filled with jet-fuel isn't even a contest. There is also the issue of leaks... a fuel leak is dangerous... an H2 or LNG leak is disastrous. Hell, the most dangerous things on a plane right now are O2 tanks, for much the same reason. Yes, part of this is the need for high pressures in the case of LNG and H2, versus jet fuel (which if you stuffed in high pressure would be a Fuel-Air bomb), but that's inescapable without some material liberating H2 within a fuel cell.

Anyway, as for "Ejyfidgetwaddawaddahakala", I agree... reality is no substitute for SFX. Of course, if you SEE this in real life, and not a picture, it's a bit more impressive I imagine. The word "surreal" springs to mind.

 

[mheslep]

Jet fuel really isn't that dangerous... it requires the proper mixture with oxygen to "go boom". LNG is pretty well studied, and a blast from a propane tank vs. a similar vessel filled with jet-fuel isn't even a contest. There is also the issue of leaks... a fuel leak is dangerous... an H2 or LNG leak is disastrous. ...

FrameD, I provided sources for the various relevant combustion facts on H2 vs hydrocarbons, use them.

 

[Frame Dragger]

FrameD, I provided sources for the various relevant combustion facts on H2 vs hydrocarbons, use them.

Those aren't "sources", that's a post by you. You don't address the issue of pressurization, and I believe you're ignoring some basic engineering issues here. By the way, define "jet fuel". Kerosene? A? A-1? B? If you're going to get pissy, at least do it for the right reasons. You're just going to have to explain a LOOOT about how highly pressurized H2, or LNG is NOT a bomb, compared to low-pressure, high-flash point (concentration aside) Jet Fuels!

You also should probably address the "leak" issue. You also have failed to cite a source for your assertion about the Hindenburg, and your "source" in this case, is you. If you want to be combative about this, at least come armed.

 

[mheslep]

Those aren't "sources", that's a post by you.

As linked in that post by me:
http://www.engineeringtoolbox.com/explosive-concentration-limits-d_423.html
o Kerosene lower concentration flammable limit is 0.7%, Hydrogen 4% (4-5X).
o HHV hydrogen is http://en.wikipedia.org/wiki/Heat_of_combustion" x ~170 gm/mole = ~7000kJ/mole, i.e. more than 20X more energy release per STP volume.
o http://web.archive.org/web/20060905074536/http://www.hydrogen.org/Knowledge/w-i-energiew-eng2.html", hydrogen's main danger:

The minimum required ignition energy required for a stoichiometric fuel/oxygen mixture is for hydrogen 0.02 mJ, for methane 0.29 mJ and for propane 0.26 mJ.

Also see:
Airbus's work with liquid H2 planes, especially slides 21-24 on safety http://www.fzt.haw-hamburg.de/pers/Scholz/dglr/hh/text_2001_12_06_Cryoplane.pdf" .
http://web.archive.org/web/20080607080532/http://www.hydrogen.org/Knowledge/w-i-energiew-eng2.html

References for H2 horrors and 'bombs', about how jet fuel is 'not dangerous'?

 

[Frame Dragger]

As linked in that post by me:
http://www.engineeringtoolbox.com/explosive-concentration-limits-d_423.html
o Kerosene lower concentration flammable limit is 0.7%, Hydrogen 4% (4-5X).
o HHV hydrogen is http://en.wikipedia.org/wiki/Heat_of_combustion" x ~170 gm/mole = ~7000kJ/mole, i.e. more than 20X more energy release per STP volume.
o http://web.archive.org/web/20060905074536/http://www.hydrogen.org/Knowledge/w-i-energiew-eng2.html", hydrogen's main danger:

Also see:
Airbus's work with liquid H2 planes, especially slides 21-24 on safety http://www.fzt.haw-hamburg.de/pers/Scholz/dglr/hh/text_2001_12_06_Cryoplane.pdf" .
http://web.archive.org/web/20080607080532/http://www.hydrogen.org/Knowledge/w-i-energiew-eng2.html

References for H2 horrors and 'bombs', about how jet fuel is 'not dangerous'?

I didn't say that jet fuel wasn't at all dangerous, I said,

Jet fuel really isn't that dangerous... it requires the proper mixture with oxygen to "go boom". LNG is pretty well studied, and a blast from a propane tank vs. a similar vessel filled with jet-fuel isn't even a contest. There is also the issue of leaks... a fuel leak is dangerous... an H2 or LNG leak is disastrous. ...

You're also not addressing the issue of PRESSURE! H2 under pressure in a tank = BOMB. Jet Fuel in the same circumstances = BOMB! (specifically a Fuel-Air Bomb). You can't drag a zeppelin filled with hydrogen behind you as a fuel source... this is an issue. One you continue to ignore, by focusing only on fuel-air mixtures and relative combustibility!

As for you second link, this is what I get:

Not in Archive.



No archived versions of the page you requested are available. If the page is still available on the Internet, we will begin archiving it during our next crawl.

This is not helpful as a source to me, and while I'd like to read it, I'd also like to know why it's no longer there.

 

[Ouabache]

http://news.bbc.co.uk/1/hi/uk/8623364.stm
From the BBC.

Were you able to save some ash in a vial?

A geology friend gave me a vial of ash from http://s-tiger.photovillage.org/photosDir/2369/thumb/800-JLM-NatGeo-Mount_St_Helens-1980-May_18.jpg" blow.. (located in Pacific Northwest US)..