weapon system idea and questions

[padren]

Please move this to physics if it is better posted there: I am not sure the best place for it (its also kinda a chem question too)

 

Basically, I've been playing with an idea for scifi reasons but I am interested in conventional applications as well: liquid fuel propelled munitions.

 

Basically, instead of having a shell and the explosive load tied together in a single unit, I've been wondering about using hydrogen/oxygen (or other fuel) in a combustion system not unlike the cylinder of a car to propel a round.

 

The advantage would be smaller munition magazines that held more, and the ability to dial up or down the power of any given shot when over-penetration is a concern.

 

Another thought would be introducing other elements into the mix if needed, and delivering a very high voltage arc to the mix to create a more higher powered explosion by charging the mix as it ignites, which I think would be basically creating a plasma.

 

I like the idea of adding electicity partly because electrical energy storage and disapation is on a seperate technology teir from the chemical elements, and on something like a naval vessel (many nuclear now) comes in very compact production methods.

 

With the advent of more modern systems that counter missile attacks by near-target automatic anti-missile fire, the ability to deliver a payload at higher speeds than missiles can achieve could become a real nessecity and bring turret based weapons into more promenance.

 

So my I am curious about:

 

* Are there currently liquid propellant projectile weapons in use?

* Are they as effective as powder based rounds?

* Can the addition of a high voltage charge increase the explosive capacity of the propellant?

* Would any specific mixture be better than another, and would the addition of other elements increase the power yield when high voltage is applied?

 

 

I originally thought this up as a way to make a cool space age "sci fi" pistol type weapon, but I like to figure out how realistically applicable something is as well.

 

Any thoughts?

[YT2095]

lol, I made one at the age of 13 (some 26 years ago), it`s not original

 

and yes they do work perfectly, although with the materials I had I could only just about beat my friends .22 riffle (at close range) his was live ordinance, mine shot ball bearings.

 

that`s my thoughts

[Gilded]

Don't get discouraged by YT. He has probably built every weapon and gadget you can think of, and some you can't.

[[Tycho?]]

There are a few disadvantages to a system like that.

 

1) You have two things to reload. Ammo, and propellant. Two is more akward than a single contained package.

 

2) Your gun, even with not ammo in it, is now quite explosive.

[YT2095]

reload like I did, mine was fully automatic on a spring based system with the projectiles loaded into a clip.

like any gun, you have to change the clip when you`re out anyway, so there`s no real disadvantage there with this system over any other type.

 

live ordinance is explosive too, so no real loss there either

[Phi for All]

It sounds like a great idea. I, too, like the idea of being able to dial up or down on the propellant charge.

 

Something I've always wondered about was the explosive charge in a self-propelled shell. How does it not go off when the shell is fired? Impact with the ground can't be that much different than being explosively fired from a launcher. Is the explosive charge activated after being fired?

[YT2095]

the propelant hits the Back end of the shell, that contains the Main charge (TNT for instance). a general rule of thumb is that the higher the explosive, the less sensitive it is also.

it requires a detonator cap to propogate the needed shockwave to set it off, that`s accomplished by the det charge screwed into the ogive.

that will contain a reasonably sensitive primart, then a booster and then the main charge all pressed into one sealed unit.

it`s That which will set off the TNT (or whatever) in the shell.

 

naturaly the only force the sensitive part will "feel" will be hitting the dirt, denting the metal and setting off the primary, air resistance will NOT do this.

 

of course, it would be a different story if you loaded the thing into the case Backwards ))

[insane_alien]

sounds a lot like the potato cannon i accidentally blew up a while ago.

[Phi for All]

sounds a lot like the potato cannon i accidentally blew up a while ago.

What was your propellant?

[insane_alien]

propane. or i would hook it up to the mains gas and use that well, i'd bottle some of it i didn't actually just have a pipe straight from the pipe, that would have been too dangerous.

[Glider]

Something I've always wondered about was the explosive charge in a self-propelled shell. How does it not go off when the shell is fired? Impact with the ground can't be that much different than being explosively fired from a launcher. Is the explosive charge activated after being fired?

High explosive shells (HESH rounds) require detonators to set them off. If you take out the detonator, then even the shell hitting the ground won't set them off.

 

This is useful in two ways. Fisrt, it means there's no risk of the shell going off in the breech (which would be bad). Second, you can decide when, and therefore where, the shell goes off. For example, you can use a barometric detonator for air-burst. You set it to certain altitude and when you fire the shell the detonator primes (goes live) as the shell achieves a certain altitude (as determined by atmospheric pressure), and goes off when it comes back down to that altitude. This is good for clearing trenches.

 

You can also use a type of detonator that requires impact to prime it, so the shell hitting the target makes it live, then a timer sets the shell off (after a delay of a few milliseconds). This is good for doing structural damage as you can make sure the shell is buried in the target before it detonates.

 

There are a whole bunch of cunning detonators and shells you can use. It all depends on what you're delivering; HESH, gas, fluids/liquids, grenades, chocolate, propaganda leaflets etc.

[JesuBungle]

Torpedos on Soviet submarines actually use a similar sort of propulsion. Only they mix something with hydrogen peroxide, I forget what. But yeah, an example of how that can go wrong is the Kirsk, where one of the torpedos blew up in the tube.

[YT2095]

your probably thinking of T-Stoff there.

H2O2 can be used as a monopropelant too though, but eitherway, it`s nasty stuff, esp at the concentrations required for use.

[bigOz]

your probably thinking of T-Stoff there.

H2O2 can be used as a monopropelant too though, but eitherway, it`s nasty stuff, esp at the concentrations required for use.

 

And I heard the North Koreans found out that the Western world hates "gingers"! Hence they are loading the hydrogen peroxide plus some kind of orange dye "bottom side up", so that when it explodes the polluted atmosphere will turn everyone's hair to ginger. Thus causing anarchy and terror between the members of the concerned society.

[padren]

Would adding the electical charge help boost the power of the explosive propellant?

 

My largest concern would be heat - you don't want the chamber to get hot enough to ignite the fuel as its been injected...on a weapon platform system you could use cooling coils I am sure, but I am not sure how hot a weapon would get from rapid fire. Internal combustions engines seem to do okay with just forced air and a radiator.

 

The other benefit is there is no shell ejection - the propellant is burned up and the slug is fired leaving the chamber empty and ready to reload faster. If it is H/O based I imagine water could be an issue but it would have to cool to condense.

[insane_alien]

chambers can get VERY hot when rapid firing. some guns you can only fire constantly for about 2 minutes before the chamber and barrel are red hot.

[YT2095]

I used Oxy-acetylene gas in mine, never had a problem.

mine also was electrical ignition triggered by the fill-up valve closing.

if the chamber is smooth with no sticky-outy bits like swarf or even bad lathe work ridges, there should be no "Hot Spots", just avoid sharp edges and angles, make them all curved inside and smooth.

[insane_alien]

YT, i was talking about a gun that fires roughly 50 rounds per second not your average backyard fully automatic potato flinger.

[Rocket Man]

two ways to do it, electricity can be the main power source or you could use the straight combustion.

IIRC, they actually weighed out the propellant for the old guns on rotnest island, they shoved the shot in the barrel followed by cordite(?) wrapped in a type of cloth, sealed the back end and let rip. they had awesome accuracy over several kilometers for such low tech (books of trig ratios ect)

 

Sam Barros has fired a prototype using electricity as the main source.

http://www.powerlabs.org/electrothermal.htm

 

otherwise i reckon peroxide is the way to go. maybe injected into a solid fuel cartrige with a bore hole down to the nose. essentially turning it into a miniature hybrid rocket engine.

[Sequence]

slightly off topic but I've had some ideas for somthing similer. (maily in English class when i'm not paying attention) Magnerically powered rifles. Along the lines of the scifi "rail gun". Have some kind of super powered magnet at the front of the barrel or behind the round. When it is activated the magnet either pulls the round toward it or pushes it away.

 

btw, this is the idea of a 16 year old who has no physics knolage besides DRT equations.

[Klaynos]

rail and coil guns have both been developed. They have a tendency to rip themselves to pieces after a few rounds, and also be quite large and guzzel energy.

[mr d]

Hello

 

Kinda like caseless ammo, such as used in a system like Metal Storm, though it may use other forms.

 

Helps reduce the need for mechanical systems in the weapon.

 

Mr D

[mr d]

Hello

 

Thought I should add something to be on subject.

 

Problem with liquid would tend to be the weight issue. If you've ever lugged a gallon of milk about for a while you'd know why.

 

So how much liquid fuel would your munitions need, what would be the weight ratio compared to conventional rounds.

 

Weigh would have to be calculated for tranportability by trucks and planes. And what would be the operational limits, if any, regarding temperature ranges. Also as certain types of liquid propellants breakdown faster than standard chemical propellants, what would be shelve life of ammunitions produced and underwhat storage condictions would it have to be housed?

 

Lastly cost of liquid propellants tend to be higher than chemical, and more complex in manufacturing. what would be the advantages of your type of weapon over current ones to warrent higher costs, plus the added cost for building up the manufacturing needed for your product.

 

Mr D

[Rocket Man]

slightly off topic but I've had some ideas for somthing similer. (maily in English class when i'm not paying attention) Magnerically powered rifles. Along the lines of the scifi "rail gun". Have some kind of super powered magnet at the front of the barrel or behind the round. When it is activated the magnet either pulls the round toward it or pushes it away.

 

again, Sam Barros "power labs" has both railguns and coil guns. (definately worth a look)

theres many ways you can modify the behaviour of a simple railgun to be more efficient or powerful but the main issue of all these sorts of weapons is the power density of your supply. a 50kg capacitor bank might store as much energy as the chemical energy in a small bottle of apple juice. and takes substantially longer to charge than a replacable packet of powder.

[padren]

Hello

 

Thought I should add something to be on subject.

 

Problem with liquid would tend to be the weight issue. If you've ever lugged a gallon of milk about for a while you'd know why.

 

So how much liquid fuel would your munitions need, what would be the weight ratio compared to conventional rounds.

 

Its not weight so much as that liquid is denser - more mass in less space, but that should also mean more explosive power per cubic inch. I don't know much about solid chemical reactions vs liquid ones such as gunpowder's potency vs something like jet fuel or hydrogen/oxygen etc, but for some reason I suspect liquids would be more effecient.

I am curious if anyone has the facts on this factor.

 

 

 

Weigh would have to be calculated for tranportability by trucks and planes. And what would be the operational limits, if any, regarding temperature ranges. Also as certain types of liquid propellants breakdown faster than standard chemical propellants, what would be shelve life of ammunitions produced and underwhat storage condictions would it have to be housed?

 

Lastly cost of liquid propellants tend to be higher than chemical, and more complex in manufacturing. what would be the advantages of your type of weapon over current ones to warrent higher costs, plus the added cost for building up the manufacturing needed for your product.

 

Mr D

 

The main advantages that I would see is

 

a) faster chamber reloading as no casing needs to be ejected

b) dial power up or down depending on need

c) liquid feed to chamber allows for easy fast injection systems, leaving only the more streamlined caseless projectile to require being fed by belt

d) smaller lighter munition belts as the explosive is not attached, or simply more rounds in less space for storage

e) only explosive tip munitions would be dangerous to handle - since all normal rounds would be just metal.

f) on platforms such as nuclear destroyers and carriers, hydrogen/oxygen could be produced from sea water (if that is a decent fuel - but it works for NASA) on-ship and not require restocking other than just munitions...which would take up a lot less space.

 

Whether in a turret platform or made really compact for field use, I would not suggest it as a standard replacement, but a more high end weapon for specific needs, such as very high caliber at very high rates of fire. It would probably cost more but if it filled a role better than other weapons...we already try to offset our casualties by spending more on technology and on the whole it seems to be a pretty good policy.

 

Edit:

Btw, side idea for the large hand-held version: secondary chamber ahead of the main one that provides counter-thrust near the end of the barrel, fanned out at 45 degrees and tilted slightly up - basically to neutralize both recoil and barrel pitch. Would that be an effective way to counter those effects?