"implosion" launcher

[jackssmirkingrevenge]

Followingthis revelationby D_Hall (which I'm sure will shortly be unlocked) I wonder if it could be applied in a practical manner by those without access to silly quantities of C4.

Here's a concept, using a screw capped tin or maybe a PET bottle, full of light gas attached to a barrel with a burst disk in between, all housed inside a hybrid chamber...

Recently at work I hooked up a 55 gallon drum to a vacuum pump to prove a point, the result looked a little something like this - if you can get that collapse wit ha few psi difference, well...

No plans to actually build this, but there seems to be some merit to those looking for high supersonic velocities without solid propellants.

[Insomniac]

Interesting concept, but it seems pretty flawed. There will be a lot of energy wasted deforming the inner chamber, and the inner chamber won't fully crumple, effectively creating a lot of dead space. Plus, there's a lot of surface area to cool the combustion gasses, which can't be good. Admittedly, the inner chamber, if heated, would still transfer that heat energy into the projectile's acceleration, so I'm not sure if this would be detrimental to the performance.

I think this is a design that really does require silly amounts of special chemicals to be practical.

[jackssmirkingrevenge]

Interesting concept, but it seems pretty flawed. There will be a lot of energy wasted deforming the inner chamber, and the inner chamber won't fully crumple, effectively creating a lot of dead space.

In the case of a hybrid driven launcher, a piston is probably a better idea.

Plus, there's a lot of surface area to cool the combustion gasses, which can't be good. Admittedly, the inner chamber, if heated, would still transfer that heat energy into the projectile's acceleration, so I'm not sure if this would be detrimental to the performance.

That's what I was thinking, hot pressurised helium... which could also be pre-pressurised to compensate for the dead space.

I think this is a design that really does require silly amounts of special chemicals to be practical.

As I said, no intention of building it, but an interesting option to put out there.

[inonickname]

I think the low pressure gas mixes hobbyists are capable of pale far too much compared to the attributes of HE confinement. The pressure, temperature, energy density, VOD etc. of solid HE's can't be matched. Even a weaker solid prop will compress and heat carbon into diamond easily- the gas mixes we're capable of will barely warm it up.

Unfortunately the propellants we have probably won't let this be effective.

[POLAND_SPUD]

In the case of a hybrid driven launcher, a piston is probably a better idea

Acctually I think that a combustion light gas gun is a much more practical idea

If I understand the concept correctly a CLGG is just a hybrid fuelled with a light gas (hydrogen)

the result looked a little something like this

A woman who can do that with her mouth is a real treasure

[inonickname]

In the case of a hybrid driven launcher, a piston is probably a better idea

Acctually I think that a combustion light gas gun is a much more practical idea

If I understand the concept correctly a CLGG is just a hybrid fuelled with a light gas (hydrogen)

Yep, probably right there actually. Gaseous mixtures don't have the excess power to lose energy through multiple stages. Basically... some even use methane. You can also use a light buffer gas too (nitrogen is a buffer gas from air, whereas the buffer used here would be a light gas).

A ram accelerator has the most potential for standard gas mixes in my opinion, but they either require complex barrel construction and complex projectile construction, or complex projectile construction. They also need high input velocities, circa 500+ m/s.

[jackssmirkingrevenge]

Unfortunately the propellants we have probably won't let this be effective

I lack the time or interest to calculate the potential energies involved, but I agree that unless insane mixes are used, you probably won't get greater helium pressure that you could from a commercial high pressure cylinder. According to NASA they manage "hundreds of thousands of pounds of pressure" with a two stage gun.



Interesting how they use a nylon piston which apparently squashes into the cone. One advantage of the implosion setup is that there is no fast heavy piston to stop...

If I understand the concept correctly a CLGG is just a hybrid fuelled with a light gas (hydrogen)

looks like it:

Combustion Light Gas Gun (CLGG)

This gun is not to be confused with a two or three stage light gas gun. The only common element is the use of hydrogen or helium. The CLGG has experimentally demonstrated velocities > 4 km/sec (13,120 ft/sec). It has (in some experiments) demonstrated a muzzle energy increase of 400% when compared to conventional powder guns. The CLGG uses no electrical power supply or conventional gun propellants.

A woman who can do that with her mouth is a real treasure

... or a health hazard!

I had a girlfriend who could probably do this

[jhalek90]

I had a girlfriend who could probably do this

:tard:

The concept of a LGG has always appealed to me.

the only issue i see is crafting a design that can be used more than once, with out the need for replacing expensive parts.

[jackssmirkingrevenge]

the only issue i see is crafting a design that can be used more than once, with out the need for replacing expensive parts.

I think this is an advantage of the "implosion" variation, in that a cheap and easily replacable chamber like a soda bottle can be used, and this would be the only component (except the burst disk) that would need replacing after every shot.

It certainly beats having to machine a new piston every time, unless you're going for a one-off "record breaking" attempt.

[inonickname]

I had a girlfriend who could probably do this

:tard:

The concept of a LGG has always appealed to me.

the only issue i see is crafting a design that can be used more than once, with out the need for replacing expensive parts.

An effective light gas gun and parts that aren't complex, expensive and need replacing are absolutely and completely mutually exclusive.

[ramses]

I had a girlfriend who could probably do this

:tard:

The concept of a LGG has always appealed to me.

the only issue i see is crafting a design that can be used more than once, with out the need for replacing expensive parts.

An effective light gas gun and parts that aren't complex, expensive and need replacing are absolutely and completely mutually exclusive.

not so; CLGGs are relatively simple and not disposable. They're basically hybrids.

[Hotwired]

:tard:

The concept of a LGG has always appealed to me.

the only issue i see is crafting a design that can be used more than once, with out the need for replacing expensive parts.

An effective light gas gun and parts that aren't complex, expensive and need replacing are absolutely and completely mutually exclusive.

not so; CLGGs are relatively simple and not disposable. They're basically hybrids.

IIRC the plastic piston gets partially extruded when it hits the end of the tube and needs to be machined out. Sounds like that isn't a reusable part

[jackssmirkingrevenge]

IIRC the plastic piston gets partially extruded when it hits the end of the tube and needs to be machined out. Sounds like that isn't a reusable part

You're confusing a two stage light gas gun with a combustion light gas gun, not the same thing.

[ramses]

They're basically hybrids.

[jackssmirkingrevenge]

They're basically hybrids.

From this article.

The CLGG uses hydrogen and oxygen as a propellant, Kruczynski said. Hydrogen and oxygen, which is a type of rocket fuel, are stored separately and pumped into a pressure chamber at the breach-end of the barrel. An igniter causes the mixture to explode, and that explosion propels the shell.

Clearly they're dealing with slightly higher mixes than we are though...

The CLGG can fire a much larger shell at more than 8,000 feet per second

The advantages of a potential naval system are quite compelling:

Advantages of the CLGG include:

* Cheaper: Shells for the new gun can be made for about one-tenth the cost of a missile.

* Faster: Projectiles reach maximum velocity almost instantly, meaning a shell can reach its target much faster than a missile or an aircraft.

* Safer: The hydrogen and oxygen will be stored in liquid form in different parts of the ship, making it more stable.

* Easily removed: Hydrogen and oxygen can be pumped out of the ship quickly and easily. This would be helpful in the event of a fire on board. It also can be dumped when the ship docks.

* Environmentally friendly: Because hydrogen and oxygen are elements, dumping them into the ocean poses no environmental risks.

* Easily replicated: Naval vessels can be rigged with devices that can remove hydrogen from the water and oxygen from the air, meaning ships have a limitless supply of propellant.

I wonder if they'd inject it directly into the chamber or use cartridges