Fuel-Air Explosives

Because the fuel/air cloud doesn't behave as a sensitive primary explosive so can't make DDT upon ignition by flame. For example, TNT will burn nice and quietly when molten and exposed to flame though it will never detonate. The fuel cloud behaves similary insensitive and it's sensitivity will quickly drop even further when the mixture is too rich in fuel (too early) or too rich in air (too late). The reason is that the atmosphere only contains 21% oxygen, if it were composed of 100% oxygen things would have been much easier! The large amount of inert N2 absorps a lot of the heat liberated from the detonation, making it very insensitive. Furthermore, the fuel is dispersed as a fine mist, but still, these droplets have a very large size compared to the intramolecular distances between fuel and oxidizer like that in regular HE's.Some fuels allow a larger time frame than others, but in general the sensitivity of mixtures with gasoline are so insensitive that they will not detonate reliably even in a EBW fired professional setup, this is why they use other fuels or oxidizer additives to complement the fuel. ...

This was the third question I was refering to btw, I mean why would they use two charges with precisely determined delays if some romantic candle light would have done the same?

Amazing what people can accomplish if you stimulate them a bit!

Yes, I use electric firing on occasion as well. A simple ignitor may look like it fires imidiately, though on a ms scale I'm quite sure two ignitors may be worlds apart! Ever used an slightly more empty battery? You will see that this difference becomes even larger, some fire after seconds, others far under a second. The more juice you pump into the ignitor, the faster and more reliably it will respond, with EBW firing beeing the upper limit...

I wouldn't mind you proving me wrong though!

[Edited on 11-2-2007 by nitro-genes]

Quote:

Originally posted by nitro-genes Yes, I use electric firing on occasion as well. A simple ignitor may look like it fires imidiately, though on a ms scale I'm quite sure two ignitors may be worlds apart! Ever used an slightly more empty battery? You will see that this difference becomes even larger, some fire after seconds, others far under a second. The more juice you pump into the ignitor, the faster and more reliably it will respond, with EBW firing beeing the upper limit... I wouldn't mind you proving me wrong though! [Edited on 11-2-2007 by nitro-genes]

I done a bit research on that!
Those comercial detonatorsa are wery wery sensitive,
and eawen the slightles curent will detonate them instantly!
However,mine homemade detonators have some delay,and I often linked one instant and one homemade to make delay betwen 2 detonations!
And the best thing is to conect 2 9V baterryes together serially(stick them together with the duch tape,and conect one + with one -,and you will see how strong it becames!)

O.K. I must explain you spmething about comercial detonators,if you have 2 or more detonators conected paralel
some of them have dellay and some of them do not!
Now when you pass curent trught them they WILL all be ignited at the same moment,those instant and those with dellay,butt those instant will explode instantly,and those with dellay will have their retardators ignited and will explode afther some time!Understand me!
Cousin of mine was working in explosive factory,soo you hardlly can beat that!(Yust jocking)

I've been cleaning floors in a bread factory as a student, still know shit about baking bread though... (just kidding)

I didn't know you were talking about commercial delay detonators btw, they would be far more reliable than any homemade ones I guess. Still it wouldn't be an easy job, be sure to capture it on video if you make any attempts!

For fuels you would like a broad mixture range with air in which the fuel cloud is still able to detonate.

-->http://en.wikipedia.org/wiki/Explosive_limit

Propylene oxide(l) is about 2-36% and ethylene oxide(g) is 3-100%, probably due to explosive polymerization, just like vinyl compounds can do. In practise they use a mixture of both because ethylene oxide alone also polymerizes on storage and has an extremely high vapour pressure due to is low boiling point (10 deg C). The mixture is probably a trade off between detonability and energy since ethylene oxide is partly oxidized having an oxygen attached, so proplene oxide would release more energy on a weight basis than ethylene oxide. Looking at l.e.l. and u.e.l. it turns out that there are only a few fuels that are usable, with diethyl ether beeing the best option considering explosive limits (equals propylene oxide) and energy release, although obtaining a few liters for an experiment would be both costly and difficult. Methanol has the same explosive limits in air as ether does, though would release substantial less energy on a weight basis due to the carbon beeing already partly oxidized. Ethanol would possibly be the only real OTC options for an FAE with one fuel compound, though this is rarely found without any water. Water having an extremely large specific heat would take up a lot of heat from the detonation, making the fuel cloud possibly much less sensitive then with anhydrous ethanol...

I've also read about additives like butyl nitrite and propyl nitrate beeing added to regular gasoline too make them usefull as a fuel, though it needed high percentages of them (10-20%) which would make things much more costly and laborous. Methanol or ethanol with 5-10% of nitromethane could work as well as a simple and easily made mixture. A real easy additive to sensitise hydrocarbon fuels would be nitric acid, though most of the fuels are either incompatible with that or do not dissolve. Some perchlorate and nitrate salts would make nice additives as well, as I know for sure that at least some of them can dissolve pretty good in ethanol or methanol...

[Edited on 13-2-2007 by nitro-genes]

You theory sounds perfect butt it is still a teory!!!!
I understand that you want to help, butt posting souch theoretic science factscan only led us to confusion!
Firstly leave or ignore chemicals like ethylene oxide,Propylene oxide,extremly sensitive,poisonous and expensive materials alone becouse we mortals will never be able to eaven see one fo those! RIGHT!?
For example i never saw nitromethane or concetrated nitric acid in my life butt I still use a lott of explosives!
There is nowhere to buy NM in my country,and you cann only steal 30+ years old nitric acid in the school!

Butt you cann pretty easily make anhydrous ethanol!
Yust buy 94-96% ethanol or wery wery strong fire water we call
"prvina"(that is redestiled greape fire wather)
and putt some chunk of Calcium Oxyde(CaO) in it!
And that is that!

If you find some FAE mixtures with rates plase post them!

P.S:How do you make your homemade electric detonators!

[Edited on 13-2-2007 by mfilip62]

Maybe you can steal a couple of liters of ethylene or propylene oxide from your junior highschool, I'm sure they will have it stocked up by the gallons for FAE demonstrations to pupils and for making mustard gas...

I merely tried to give my thoughts about the possible fuels usable for FAE in the hope to get some meaningfull opinions of others and start a discussion about it on this discussionboard. If this is all too much for you, I'll stop discussing it and you can start experimenting with them right away without thinking about concequences, availability or possible flaws of your method...

Surely someone that has made enough ANFO to blow up a car will not worry about the police in front of his door over some gas explosion. Which have absolutely nothing to do with fuel/air explosions btw...

The more powerfool the better eh?

[Edited on 14-2-2007 by nitro-genes]

I agree with you nitro-genes butt when you buy
presurized gas here you actually just rent gas container!
If you destroy it or blow it up....you have wery long procedure to go trought,first you must have some personal ID to rent it,if you want to buy etine,you must have in writing proof that you are able to handle with that kind of material,(and allmoust for every kind of gas!),report the status of container
every 3-6 months(depending on the tipe of gas) to the company,and if you "lost" it, they report that to the police...
and then starts real problems!!!
You must know that lawsuits here endure for ages,
bureaucracy is insane,and coruption...
I dont want that kind of charade,that is for sure...

I know what I am talking about!!!!

It is probably becouse Al-Queda attack killing few persons
and destoying police station 1994.!
(Stupid moslems from Bosnia!)

Only potential hazardous chemical that is not restricted is KAN,
(AN/CaCO3/MgCO3)chamical fertilizer,and H2O2 which is semi restricted!

It is paradoxically that mine country is full of explosives left after war,and some stupid idiot put ban on chemicals!
(Butt you must agree that a lot of explosiwes left is not such bad thing)

Belive me that explosion of C2H2/O2 mixture is anything butt
ordinary gas explosion!I saw it once!
It actually erase EWERITHING on it way!

Lol, just for fun calculated the optimum humidity of water vapour in the air to be stoichiometric with the amount of oxygen for the formed acetylene to combust with. Though even with a relative humidity of 100% at 20 deg. C. (20 grams of water per m3 of air) there is still a 7 fold excess of oxygen compared to the water, or 1.2% of acetylene in air, which is lower than it's l.e.l.. So unfortunately enough this is not going to work without any water added, air just can't hold enough water, even at higher temperatures...

I doubt that even a very brisant charge could pulverize a 100 times it's weight of rockhard CaC2 into a very fine powder anyway...

[Edited on 14-2-2007 by nitro-genes]

This post may not belong if not my apologys.

Just a thought but has anyone looked at reports of coal dust explosions in mining accidents and grain dust explosions occuring in grain handling facilitys?

The requirements/conditions for detonation versus deflagration are very well documented with extensive testing
determining optimum concentrations/specific materials even specific type of coal which will detonate rather than simply deflagrate.As anyone who was alive back in the '70's will attest particularly us midwesterners is that a grain dust explosion can be extremely destructive,crushing reinforced concrete structures with impunity.I would suppose flour
with its large nitrogen content would work as well if not better than grain dust fines.Its been awhile since I read a few of the reports which I saved as they seemed a real possibility for a successful enclosed at least dust/FA explosive.
Therin lies the problem however these explosions require confinement as one of the 5 legs of a successful dust detonation.fine if your target is a cave or a relatively open building but likely useless out of doors.

Suprisingly enough there is also only one type of coal which will detonate. Unfortunately I cannot recall the variety that will detonate under proper conditions or which dust, coal or grain contains the most energy however i do recall that common corn starch IIRC had the most energy upon detonation of the grain dusts.To be honest so much information is contained in the accident reports and investigations they are virtual manuals for construction of a successful device
[Edited on 8-3-2009 by grndpndr]

[Edited on 8-3-2009 by grndpndr]

Just this evening a documentary about renewables and alcohol revealed it required nearly the same amount of fossil fuel to produce an equivalent amount of alcohol.
I would expect farming sugar cane/beets would be equally as expensive in terms of resources.Personally think corn or any foodstuff used to produce fuel is a very poor way to goAs well the resulting ash from direct injection of coal dust in a traditional piston engine would make for a very short lived powerplant as was pointed out.Perhaps some other design to take advantage of the overpressure /wind speed.
Turbine of some type, with a precombustion chamber?Coal fired anything is a very dirty device so a mechanism for pollution control just might make such an engine size impractical?

As far as FAEs 497 I guess it depends on ones intentions for his device.iirc figures like that rival the effects of nuclear devices at varying distances, I for one would avoid exposure to anything approaching 90psi overpressure and 200mph windspeeds.An individual needent be IN the explosion to be killed by the overpressure or windspeed of the dust explosion. respectfully

[Edited on 14-3-2009 by grndpndr]

[Edited on 14-3-2009 by grndpndr]

Im geting dangerously far afield and yes I am disturbed by ranchers/farmers the largest entitlement group I am aware of driving new 1ton duallys to town for grocerys.But factually land must rest.ergo paid for planting nothing or preventing overgrazing which is extremely devestating denuding mainly national grassland thats been leased not owned by the ranchers yet treated as personal property when it comes to hunting etc on our land.Sorry for the rant.

Dust explosions rock! Ask the dead.

Years ago when i worked seismograph I had electronic delay detonators of various delays,shame they were essentially wasted.
as in reqular nondelay caps.I would want to be a substantial distance from the oxy acetylene explosion filled a few balloons while oxy
acetylene welding a few times cant imagine an entire home filled with a correct mix!Heck a guy could put plastic over the broke out windows use a little caulk and foam little ciphering for mixture and...
doubt a fire truck could be summoned in time or even the fire /explosion discovered until smoke rising in the horizon.
Not a good style if one wanted to keep his hobbys private even though it would be some time before the Unfortunate "lightning strike" discovered.
Appreciate the file 497

[Edited on 18-3-2009 by grndpndr]

I don't think there would be anything very solid left for the fire department to put out.

I thing I'm safe, considering I don't have the means to test a design like that now or any time soon. People publish far more "dangerous" ideas/designs all the time over at RS with no repercussions. It's not anything extremely original, just an adaptation of designs that our own military and patent service have published.

[Edited on 18-3-2009 by 497]

Me either its just a fun topic of discussion that just happen to enjoy.To actually commit such an act is so far from my comfort zone or need for kicks the very idea is laughable but the actual disussion god help me I do enjoy.

A middle age adolescent in that respect.Could be worse,I could be the local deputy who patrols our small town a few hours a week under arrest for essentially being a sexual predator against the civilians he was sworn to serve and protect but charged with 3 counts of rape ,.1of giving false info to states CID.

Quote: Originally posted by Microtek

From that article on solid fuel FAEs, flake aluminum seems to be a very effective fuel. I wonder then, since a 1:1 magnalium alloy is so brittle, how about packing a brisant HE inside a magnalium cylinder? Maybe the detonation would produce (and disperse) magnaluminum particles of a sufficiently small particle size that it would be useable for FAE purposes...

Using the magnalianium alloy as a container the resulting detonation/blinding fireball ignitingtoDDT the fuelSuch as a flake AL.How about titanium /al alloy?supposed long lived ignition source? surround over the device suspended off the ground.I dont recall that the article advised containment was a leg of the detonation of AL flake?I wonder if an actual container would be needed made from the magnaluminum or simply a plastic bag one with the magnaliminum surrounding the HE and another surrounding the magnaluminum fine mesh flaked AL?Unless contemplating a projectile of course

iirc magnesium is not an inexpensive metal so experiments w/o mag.would be in order,same with titanium.

Flake AL-Pottassium perchlorate! that should accomplish some type of dust explosion? found in the FAE article just a quick mention never the less even if used like the black book
inspired dust explosive I would expect some extreme fireballs at minimum hopefully detonation out of doors.Ratios would be needed but a very small scale experiment now with snow on the ground would be safe.And IIRC theres a small concrete guard shack on National grassland.To bad no balls no blue chips. by the wat besides the small guard shack theres hundreds of concrete munitions igloos complete with several ton doors intact about tyhe size of a tennis court some 13-14 miles from town. Outside locking of multiton door the trest of the bunker covered with afew feet of earth.Until a cleanup in the late 90s shells from 20mm-155mm pluis would wash out of the hillside regularly.By regs they were supposedly burned to deflagration or detonation but not carefully.Just as in riussian areas of intense ww2 combat they still unearth projectiles use a double boiler and salvage the military he filling from the projectiles selling it on the black mkt.Please excuse the excessive edits!
[Edited on 27-3-2009 by grndpndr]

[Edited on 27-3-2009 by grndpndr]

[Edited on 27-3-2009 by grndpndr]

[Edited on 27-3-2009 by grndpndr]

Quote: Originally posted by 497

Quote: I wonder then, since a 1:1 magnalium alloy is so brittle, how about packing a brisant HE inside a magnalium cylinder? Maybe the detonation would produce (and disperse) magnalium particles of a sufficiently small particle size that it would be useable for FAE purposes... I am doubtful that it would produce fragments small enough to burn effeciently. I could be wrong though.. It would be easy enough to try.. On a somewhat similar note, I know it is possible to get a lovely thermobaric effect by detonating cylinders of laminated layers of [plasticized RDX sheet -- teflon tape -- aluminum foil]. That's the warhead the "Hellfire" missiles contain, apparently it works well. Not quite an FAE though.. Still, it shows that it is possible to use metals in forms other than powder.. I'll post the patent if anyone wants..

Sounds more like a squash head SC. obsolete against modern composite armor,reactive armor and spaced armor.
like the name the thin walled warhead impacted the target material'squashing' the explosive charge into something like a pancake.When tightly compressed against the target the warhead detonated setting up shockwaves overstressing the material and causing spalling to the interior of the heaviest tanks and causing large chunks of concrete to spall from the interior of hardened buildings at several hundred MPH still devastating against bunkers/std armor w/o penetration.

You likely saw an advanced warhead design 497 that used chemical energy rather than kinetic.Regards

I sure like the teflon/al Idea ,sadly I dont indulge myself any...
Really think you should view some grain dust explosions that have occurred in concrete structures.The effects are devestating ,reinforced concrete shattered if you hadnt known better youd have swore it was a HE demolition.
They peaked around the 70s but still occur in many different situations were flammable dusts can become dispersed and ignited.90 PSI isnt a fireball! Regards
OK i looked at the link,its a thermobaric warheaad intended for use against enclosed buildings/caves.Its accuracy meant to hit tanks at IIRC 5kilometers allows it to go through windows/doors cave entrances. It is as you say an enhanced warhead using some sort of metals 'increasing pressure peaks for longer durations than normal explosives' similar effects to a dust explosion but with all that power (Heat/pressure) contained in a small package[Edited on 30-3-2009 by grndpndr] Pott perchlorate/AL dust?

[Edited on 31-3-2009 by grndpndr]

[Edited on 31-3-2009 by grndpndr]

[Edited on 31-3-2009 by grndpndr]

[Edited on 31-3-2009 by grndpndr]

Congrats! I think you are the first amateur that actually made a working FAE!

Care to elaborate a little more on the timing of the two charges, the fuel weight/explosive weight ratio, confinement and composition of both the dispersal and detonation charge?

I'm surprised that the fuel cloud was able to make DDT with only 2 liters fuel! I guess that is why you used the relatively large amount of IPN? Are you planning the same ratio's for the 20 liter charge? Maybe 10 or even 5% IPN would suffice in this case...

What is your opinion about the possibility of using methylated spirits with a good deal of dissolved ammoniumnitrate as the fuel? This would have been my fuel of choice since both are cheap and easily obtainable around here. Energy output would be somewhat less on a weight basis compared to your mix. It would be a simple mix-and-fire option, although I've never read about the performance of ethanol/methanol as the fuel in the available patents concerning FAE's...

Nitro-genes

"Care to elaborate a little more on the timing of the two charges"

Radio transmitter with multiple channels, receivers programmed to specific channels (1 and 2). Transmitter set to send out signal on channel 1 at time X, channel 2 at time Y.

"the fuel weight/explosive weight ratio"

Fuel weight roughly 1400 grams, explosive burster roughly 9 grams.

"confinement and composition of both the dispersal and detonation charge? "

Dispersal charge pure recrystallized Erythritol Tetranitrate (ETN) powder in 11mm OD vinyl tubing, inside 12.7mm ID PVC pipe, inserted in the center of the fuel. Initiating charge was a small plastic bag of cast ETN.

"I'm surprised that the fuel cloud was able to make DDT with only 2 liters fuel!"

As I understand it, DDT refers to deflagration-to-detonation transition, the general process by which a subsonic combustion wave becomes a supersonic detonation front. In this case it would be the exact opposite. The initiating charge gave the dispersed fuel a shock wave, detonating it. This detonation front traveled through the fuel until it made the transition to a deflagration. Additionally, the amount of fuel is largely unrelated to its ability to detonate, in fact larger charges would have more difficulty fully detonating than smaller tests.

"I guess that is why you used the relatively large amount of IPN?"

Isopropyl nitrite is added to increase volatility and sensitize the mixture.

"Are you planning the same ratio's for the 20 liter charge? Maybe 10 or even 5% IPN would suffice in this case..."

The 20 liter charge is tentatively planned to be a mixture of roughly 2.5 liters Isopropyl nitrite, 5 liters hexane, 12.5 liters heptane. These are rough estimates, actual content may vary.

"What is your opinion about the possibility of using methylated spirits with a good deal of dissolved ammoniumnitrate as the fuel?"

Sounds feasible, but defeats the purpose of an FAE in some ways. For me the entire idea of an FAE is to utilize non-explosive fuels and take advantage of atmospheric oxygen in creating an explosion. Using fuels with high amounts of molecular oxygen content would defeat this to some degree, not to mention using something that's already a high explosive.

[Edited on 4-16-2009 by NameWithheld]

-"As I understand it, DDT refers to deflagration-to-detonation transition, the general process by which a subsonic combustion wave becomes a supersonic detonation front. In this case it would be the exact opposite. The initiating charge gave the dispersed fuel a shock wave, detonating it. This detonation front traveled through the fuel until it made the transition to a deflagration. Additionally, the amount of fuel is largely unrelated to its ability to detonate, in fact larger charges would have more difficulty fully detonating than smaller tests."

I see what you mean, but wouldn't this mean that the initiating charge needs to be upscaled linearly with the amount of fuel used?

Pressure drops exceedingly fast with increasing distance from the initiating explosive, so I can't really see how the shockwave could propagate al the way through the fuel/air cloud without the reaction of the fuel/air mix itself adding energy to the shockwave to sustain it. This would mean that given the fuel/air cloud is of large enough size and sensitivity it would eventually sustain detonation on it's own, independant of the amount of initiating explosive.

-"]I don't think adding AN would help at all for the sensitivity of the fuel cloud. Its not a particularly strong or unstable oxidizer, and it is insensitive to shock waves."

I can't imagine that there is a lot of volatilization in those 80 miliseconds, moreover is IPN also characterized as an insensitive explosive, used for improving combustion in diesel engines. Wouldn't the insensitivity, stability and ability to mix with alkanes make IPN just a logical choice? Decomposition temperature of the additive is probably important analogous to thermobaric explosives, but this does not exclude a range of other possible additives IMO...

Anyway, can't wait to see the big one!...

[Edited on 16-4-2009 by nitro-genes]

Thanks a lot!!

it more seem to be a camera that a camcorder but if it can shoot a 1200 fps i think it will be ok for 1200$

Quote: Originally posted by 497

I often wonder what an entire building filled with stoiciometric oxygen-acetylene would look like going off...

Hell, why settle for oxygen? What I'd like to see would be the setting off of an acetylene - ozone binary mix. If held in liquid phase at low enough temperature, could pure ozone possibly be contained long enough to allow its dispersal with acetylene liquid (or snow). Probably the detonation would be spontaneous, requiring no primer.

...it would be glorious!

Quote: Originally posted by 497

If it's a hot day, you have a large initiator, and you get the timing right, you might be able to pull off a detonation with straight gasoline... It'd be interesting to see at least. About the TATP, I very much doubt you'd get a noticeable increase in velocity by adding it.. I know of no fuel besides possibly hydrogen that will detonate at over 2000m/s in air. TATP might increase the fuel sensitivity a little, but I remember reading somewhere that organic peroxides were found to be ineffective sensitizers for FAEs, but it would be easy enough to try. I must say, I seriously doubt you could generate enough acetylene quickly enough from CaC2.. But go for it if you think it could work.. If I was going to try anything with acetylene, it would be a cold saturated solution of it in acetone.. [Edited on 23-4-2009 by 497]

The CaC2 might be mixed with an explosive giving H2O as detonation product. ( An explosive not reacting with the basic carbide-ion under storage) AND hopefully the formed acetylene will NOT detonate/decompose in the same time its formed.... or it does and when this is not working

Quote: Originally posted by 497

You could probably do it.. Explosively disperse water and CaC2 together. You'd have to have a long delay to wait for the acetylene to form and mix with the air. It depends on whether the CaC2 could react much before it blew away or settled to the ground.. hope you have a lot of CaC2.

Quote: Originally posted by 497

I often wonder what an entire building filled with stoiciometric oxygen-acetylene would look like going off" [Edited on 17-3-2009 by 497]

I was looking at another thread with acetylene /oxygen as the mixed gas and deflagration or detonation velocity and whether by implication a detonator would be required.I found the results from a respected det vel. table dowloaded from this site and another i cant recall. Acetylene/oxygen @2/1 gas mixture det vel = 2660mps,2/3 ratio, 2720mps,3/1
ratio 2320mps VOD.Again whether by ignition or detonation initiated the chart doesnt mention.Safe wager would say very little left of a home let alone a reinforced bunker if detonated from the interior.Even if detonated from the exterior a large device retaining optimum overpressure would do substantial damage to a hard target and most likely kill all the occupants unless equipped with sealed compartments similar to bank vaults. JMHO

First of all, I'm Dutch. Please don't mind the misspelled crap. Im not an idiot.

I have some experience with thermobaric explosive charges based on a high explosive center charge with a surround of plastisized metal power.

Some successful test have been done by me and other members of a dutch forum called pyroforum.nl, with for example a 30 gram plastic bonded PETN centercharge along with a surround of 40 grams 70/20/10 Al/KClO3/PIB @> 1.7 gr/cc. This is all based on US patent 6.955.732.

This setup is capable of fully burning the aluminumpowder over a (relatively) extended period of time producing roughly 20 kBars of pressure. Since I don't own a high speed camera its hard to give any data on the exact time it takes for the charge to burn the completeness.

Would it be possible to use such a setup to ignite a FAE? If you can extend the burning time of your alumnium long enough for the cloud to mix with the air properly, it might be possible to use such a charge to spread the fuel, as well as igniting it at the same time.

Unfortunately the burning time of such scarges cannot be delayed by using for example coarser aluminumpowder, since from my video material the effective range of such charges seems to be limited to about 80 cm. @7000 m/s thats uuhhm, not really long. Further from the charge there is simply not enough pressure and heat.

As far as I know the burning time of a thermobaric charge cannot be extended much by the reason mentioned above. The time it takes to ignite the fuel cloud cannot be speed up either since, according to tests by other members here at SMDB, is takes at least 50 milliseconds to properly spread and vaporise the fuel with air.

If a design like this would work, it wouldn't take precise timing of seperate desperion and igniting charges. Also, there's a possibility to add more oxigen to the atmosphere by raising the oxidiser content of the earlier mentioned surround charge. This would result in a more evenly mixed cloud (oxygen from the inside out!), and therefore more effective combustion.

A possible drawback, or even failure of this idea would be that the surround charge is incapable of reaching enough atmosferic oxygen because of the 'blanket' of gasoline or whatever is in its way to burn.

Any idea's? Any data on the 'burning time' of thermobaric charges? According to US patent 6.955.732 the combustion takes from 10 to 50ms to complete.






[Edited on 30-4-2009 by Leander]

[Edited on 30-4-2009 by Leander]

[Edited on 30-4-2009 by Leander]

Quote: Originally posted by grndpndr

Maybe I misunderstand but the surround charge of a thermobaric warhead contains its own oxidizer/fuel so outside atmosphere isnt nesscessary in fact the attraction of thermobaric warheads is they work in low/no 02 enviroments.

Clearly Im behind the times.Ive never heard of a thermobaric torpedo. I am also still skeptical of AL having the ability to scavenge as it were 02 from any oxygen containing materials.
Admittedly Im a rank amateur here having read few papers or patents concerning the properties of AL in SFAE/thermobaric devices and never seeing the properties attributed to AL mentioned in any I cant argue a point Im unsure of.So,I appreciate your kind responses,thanks.
The AL reaction,basically'stealing' oxygen, o is this akin to what happens in a thermite reaction to the iron oxide?
[Edited on 11-5-2009 by grndpndr

[Edited on 11-5-2009 by grndpndr][Edited on 11-5-2009 by grndpndr]

[Edited on 11-5-2009 by grndpndr]

Thank for all the informative replies.Its very much appreciated
particularly the collective patience shown.

[Edited on 12-5-2009 by grndpndr]

[Edited on 12-5-2009 by grndpndr]

Quote: Originally posted by Lord Emrone

I have the idea to make a fireball with gasoline. 1 liter of it on top of a 200 gr ANFO charge by example. I could use BP or FP but I'm used to detonations, so I'll use that. I was thinking to use several grams of red phosphorus tightly packed in tape and place that on top of the gaz bottle. The shock will cause the RP to burn and burst out of the tape and light the gaz cloud. Anyone other ideas or suggestions ?

Quote: Originally posted by Lord Emrone

@Jimbo Jones : pieces of Teflon tape dusted with fine aluminum powder ? Is that tape an oxidizer ?

Quote: Originally posted by White Yeti

This is probably a stupid question, but how do you ignite the cloud of explosive vapour when the first charge blows up the container and everything in its proximity?

The energy of the dispersal charge is almost completely absorbed and converted
into the outward movement of the fuel. It is therefore possible to
have the initiating charge located very close to the fuel.





[Edited on 1-7-2012 by hiperion42]

A Fuel Air Explosion is achieved by using a blast to disperse the 'Fuel' into the air and then igniting the fuel cloud allowing all the 'fuel' to burn within a few milliseconds.

Fuel Air Explosive's rely on the oxygen in the surrounding air, rather then self oxidizing. The fuel is dispersed into the air to forming a cloud of very small droplets, and exposing a large amount of the 'Fuels' surface area. When the fuel cloud is ignited the 'Fuel' is able to burn almost instantly due to the fact that its in very small droplets. The smaller the droplets are the faster the fuel cloud will burn, this is the same as with Flash Powders or Black Powder.

Common fuels like gasoline, kerosine and diesel will not be able to achieve the Fuel Air Effect. To achieve the Fuel Air Effect you will need to use faster burning fuels such as Isopropyl Nitrite, Diethyl Ether or Heptane. Their are many other fuels that are suitable for use in a FAE but i don't want to mention them all.

Here is a great video of a True Fuel Air Explosion uploaded by AnonymousUploads (who sadly had to shut down his account due to a explosives related injury)
Here is the link: http://www.youtube.com/watch?v=7dW1qkBg8sM

I hope you find this useful and if you have any questions please ask

Quote: Originally posted by matheusfredrich13

Here is a great video of a True Fuel Air Explosion uploaded by AnonymousUploads (who sadly had to shut down his account due to a explosives related injury) Here is the link: http://www.youtube.com/watch?v=7dW1qkBg8sM I hope you find this useful and if you have any questions please ask