Sorta realistic space-warship

[Mikey]

IIRC, the USN has development plans for upt to 64-mJ rail guns. And the mechanism itself wasn't damaged by firing; rather, the rails kept ripping themselves off the substrate.

[Abraxas]

Railguns have a host of problems. One of the greatest is that the current flow is so great, it littorally melts the rails. The ironic thing is, even though the rails are destroyed, they're still not distributing the energy as fast as they would like...

And even if they actually get this technology to work, it's very delicate, which means intigrating it in a ship where there is constant turbulance from wind and waves, plus the addition of salt and brine, will present a problem in and of itself. Of course, then there is the energy deffecit issue which is plagueing the Navy today. They're offering mucho bucks to a company that can make energy production more efficient.

But that is neither here nor there...


gackt_camui, I love all the updates you did. I can't think of anything to say but GREAT JOB! It's coming along fabulously. The second ship looks interesting and I look forward to the different permutations that come out of it.

[Sionnach Glic]

One of the greatest is that the current flow is so great, it littorally melts the rails.

Maybe this is a stupid suggestion, but couldn't that be solved by the use of sufficiently strong materials? Surely Future-Steel must be stronger than whatever we have now.

[Mikey]

...and would have greater conductivity. The coil guns currently in development don't seem to have all the same issues, but are obviously on a much smaller scale.

[Abraxas]

One of the greatest is that the current flow is so great, it littorally melts the rails.

Maybe this is a stupid suggestion, but couldn't that be solved by the use of sufficiently strong materials? Surely Future-Steel must be stronger than whatever we have now.

Not a stupid question at all.

The issue isn't so much the metal's relative strength, but rather it's ability to withstand heat. See, as charges move rapidly through a material, they cause molecular motion in the metal which creates heat. In this case, with such high currents (which is just the number of passing charges per unit time), the heat the metals have to withstand is incomprehensible.

They have to find a metal that equally durable AND conductive... which can be tough.

In the coldness of space, rail guns would be cooled down rapidly, which makes them a popular choice for space ships .

...and would have greater conductivity. The coil guns currently in development don't seem to have all the same issues, but are obviously on a much smaller scale.

Yeah, I'm not entirely sure why rail guns are more popular then coil guns, but I imagine it has to do with the efficiency of the gun itself.

Maybe rail guns transfer electric energy into kinetic energy better... or can use smaller projectiles... or maybe they're less complicated...

I honestly don't know...

[Graham Kennedy]

In the coldness of space, rail guns would be cooled down rapidly, which makes them a popular choice for space ships

Actually that's a myth. Space isn't cold as such; temperature is a property of matter, and in space there's no matter to speak of and so no temperature.

In fact, space would be a far worse place to use a rail gun in this respect. The hot barrels would not be able to lose heat through convection or conduction into the surrounding air as they could on Earth. They could only lose heat through radiation.

You might want to think about putting finned radiators or some sort of cooling jacket on your rail guns.

[Mikey]

I guess that coil guns are more efficient for smaller guns/projectiles, because of the 360-degree nature of the electromagnets, but tend to lose more field strength as you expand the aperture for a projectile. Last I heard, US Army coil gun developments were limited(!) to 120mm mortar-types.

[gackt_camui]

ok, here goes...the animation with the side turrets(might wanna watch it with full screen, cause some parts are tiny...)
http://s175.photobucket.com/albums/w138 ... ewside.flv
the only change from the last time are the upper turrets...they no longer hang on the doors(don't know what I was thinking ), the doors open up a bit more, and the cannons have MUCH more freedom...

now about what you've been talking about...

let's do a sub topic rail guns and coil guns here's my opinion and yet again, not something I know too much about, so am willing to hear any corrections
Most of my ships weapons are rail guns, except for the coil guns on the side, and the fighters "big" cannons I prefer rail guns, cause I think their projectiles would be faster, and with that they would hit with a stronger force, so why not make all of it rail guns?
first, the side turrets are supposed to fire something like flack shells, so if they are coil guns when the projectile leaves the barrel it will be spinning like crazy, and when it explodes its fragments would scatter over a larger area which would increase its effectiveness as a flack cannon
second, the fighters ok, again, the projectiles would be spinning like crazy, and since the fighters move pretty fast on their own, so if the cannons fired while at full speed then the projectile would have similar velocity to a rail gun, but since it's spinning it could penetrate heavier armor, and dig in a bit deeper(giving the fighter a chance to do at least SOME damage to big ships )

so now comes the question does any of that make any logical sense at all or did I over imagine it all?


rail guns I imagined 3 ways how they MIGHT work but then again maybe I just had 3 wrong ideas so to those of you who know more of this topic then I do: could you tell me which(if any) of these would work best?
(the pics are really simple cause I made them in a hurry, this is just for this presentation so I made things transparent, and some parts are missing so most of it would be visible)
1. simple design kinda boring, nothing special about it I think that this would have some heating problems...
http://s175.photobucket.com/albums/w138 ... =rail1.jpg
it's just a barrel with cut out parts, don't know, but think that might make it a bit more useful

2. bit more complex design
http://s175.photobucket.com/albums/w138 ... =rail2.jpg
this time the current only magnetizes the rings and it works sorta like this first the red ring gets positively polarized and pulls the projectile toward itself, then as the projectile passes true it, it becomes neutral, and the blue ring gets a positive charge, to keep dragging the projectile, when the projectile starts passing true the blue ring, the red ring gets a negative charge to push it away form itself, and of course the green ring gets a positive charge, and so on, and so on

3. half way
http://s175.photobucket.com/albums/w138 ... =rail3.jpg
it's similar to the first design, but there are extrusions all over the rails, and these extrusions work like the rings in the second design, so it a half way

I personally think that any of these 3 designs might work, but I might be very wrong
And GK mentioned radiators so could some of these designs be modified?...like, my personal favorite is the second design, so could the part that is used like rails in the first design be used as a cooling radiator?...or could it be modified so that the rings spread a bit more, and they cool the rails from the first design?....just some thoughts, anything will be useful, even an ms paint sketch


and another question...the part I didn't think much about where radars...what type of radars would be best to use?...radio waves? some EM-thing? ...how would it look?(it it's supposed to be placed on the outside of the ship )

EDIT: for some reason the pictures didn't show...aww and I wanted it to look like a nicer presentation ...anyway, back to the good old links

[Abraxas]

In a nutshell, what a rail gun does is complete a circuit. This completed circuit creates a magnetic field that pushes a projectile. The projectile was essentially nothing but a stop-gap that completed a circuit.

Now, because it's a circuit there is charge going IN and charge going OUT, which means there are 2 rails, one for each.



The first gun would be surprisingly complicated because it has 4 rails... and even if charge were going IN and OUT through 2 of them, the other 2 would create unecassary friction. Basically, only 2 are needed.

The second gun is actually not a rail gun. It's an electro-mag gun. It works exactly like mono-rails and roller coasters do today. I don't know if the concept is any better or worse then a normal rail gun (I'm thinking it's less efficient)... but I know it's not one. Maybe GrahamKennedy can help here?

The third gun works on princibles of both... something I don't think would work well. There is just too much happening in the barrel of the gun to ensure a good shot, I think.

I would use the first gun and make it 2 barrels.


Radar systems are beyond me. I was honestly going go "Sci-Fi" and put antenna and dishes at the front, sides, dorsal, ventral and rear of my ship and set aside a chunk of my ship's volume (obviously in the C&C) for these systems.

I will say this, though: For the love of God, don't go "Wing Commander" on us and use sonar! Please!

[Aaron]

I guess that coil guns are more efficient for smaller guns/projectiles, because of the 360-degree nature of the electromagnets, but tend to lose more field strength as you expand the aperture for a projectile. Last I heard, US Army coil gun developments were limited(!) to 120mm mortar-types.

It's my understanding that coilguns are far more complicated to design and build than a railgun, requiring precision timing to switch the coils on and off as the projectile passes up the barrel. So more complicated to build and run. A railgun is obviously simpler, minus the over heating issues. At least with no atmosphere the rails won't ablate with every firing.

[Graham Kennedy]

A coil gun - sometimes called a gauss gun - an electromagnetic coil to accelerate a projectile. You have a solenoid coil - a helix - that you pass a current through. The projectile is behind the solenoid, in line with the center axis. When you run a current through the coil the projectile accelerates towards the center of it. As it reaches the center of the coil, the force pulling it forward drops to zero; the coil would actually start slowing the projectile after that point, but as the projectile hits the center you turn that coil off and just let it continue. The projectile flies towards the target, and that's your gauss gun.

That's what is called a single stage gun. You can have a multistage weapon by putting a set of coils one in front of the other. As the projectile reaches the center of one, you turn it off and turn on the next one along the line. It's just like having a whole bunch of single stage guns one in front of another. Here's a diagram I found of a three stage gauss gun :



One of the big problems with them is that in both the coils and the projectile it takes a finite time for the magnetic field to build to a peak, and then to drop to zero again afterwards. So you have to have gaps between the coils to give the field in the projectile time to die down. And since the projectile is accelerating, the gap between coils has to get exponentially bigger. So fitting large numbers of coils in means very long barrels - unfeasibly long.

Running that much current through a material that suddenly can also lead to a buildup of heat, which is a bad thing because you want that energy going to magnetic fields and then kinetic energy in the projectile, not heat. You can avoid the heat issue if you can use a superconducting magnet though.

The advantage is that the projectile doesn't need to touch the barrel, so there's no wear on either one. Barrel life is potentially infinite; contrast that to rail guns, which at the present time are usually "one barrel = one shot" deals.

[shran]

Both railguns and coilguns create a lot of heat.

Could you use the cooling systems of the guns to create extra energy? Complcated, but theoretically possible, I think.

[Abraxas]

Both railguns and coilguns create a lot of heat.

Could you use the cooling systems of the guns to create extra energy? Complcated, but theoretically possible, I think.

It would be hard (maybe impossible) to transfer the heat from the barrels of the gun to internal systems before it's dissipated into something else.

[shran]

It should be possible, as the cooling system is quite much the only place the heat can go. Space isn't an option because of te vacuüm there, and the hull is too far away and the cooling system is in between. In essence, you'll be able to win back the energy used to fire it-the energy used to launch the projectile-some energy that dissipated into something else.

[Abraxas]

It should be possible, as the cooling system is quite much the only place the heat can go. Space isn't an option because of te vacuüm there, and the hull is too far away and the cooling system is in between. In essence, you'll be able to win back the energy used to fire it-the energy used to launch the projectile-some energy that dissipated into something else.

The heat will dissipate to the pipes and then when you bring those pipes back into the ship (through a fair amount of armor) the heat will dissipate into the air or machinery it runs next to.

If the rail guns are evenly distributed across the ship's surface area, the only thing that heat can be reclaimed for it to heat the inside of your ship... and I'm thinking there are other, more direct sources of heat that can't be used.




EDIT: While working on *my* ship, I realized that at some point in it's design I switched from meters to feet... so now I've got parts of the ship that are too big or too small depending on which unit I use . So now I'm going back, starting from scratch and defining my unit convention on each piece of paper I use .

Why does America have to be so difficult? Just switch, already! All us engineers would thank you! Not to mention the physacists, astronomers, scientists and mathmaticians.