Posted on 03/02/2012 5:28:46 AM PST by Reaganite Republican
I'd reckon the 'barrel' would have to be vented, otherwise the low pressure area created behind the accelerating projectile would cause problems, either with acceleration of the projectile or with air rushing back in when the projectile left. Somewhere astern of the muzzle, there'd be a 'great sucking sound'...
It’d be like living inside a Glock.
If you shot it up and then have if fall to earth like an icbm you would reach a terminal velocity and lose the obvious speed advantage of mach 7.
:-)
Well, rocket science or not, every dime the Chicomms save on their development by stealing ours is another bullet for their rifles. The nuclear and missile secrets pissed away by the Klintoons saved them billions. IP is a competitive advantage.
The projectile would almost certainly be laser or GPS guided with pop out fins like current smart weapons, or something that would be viable at Mach 7, anyway
They couldn’t possibly be planning to send these things dumb and blind, I can’t fathom it
horizon is about 16nm at sea - as someone else noted the old battleships pinged shells downfield to 23nm. There are any number of issues that would have to be addressed in targeting (beyond the target itself) which the navy has been doing for years - weather, coreolis effect (earth’s rotation under the trajectory), spin of the shell.
Targeting would most likely be linked down from satellite or aircraft at altitude (other ships or helos that are over the horizon and closer to the target, but why risk it). At the rate of fire they mentioned and the potential kinetic energy you get 2-3 in the vicinity in a minute, minor correct 2-3 on target and move on to the next...could wipe a fleet in half an hour tops with one asset and no radiation.
Also being on a moving platform if the bombers aren’t airborne trying to eliminate the source would required very long range patrols or satellite tech to find, avoid, and destroy. If they are airborne then would lose at least a few high value assets prior to redirect.
I’m thinking long term the boomers (ballistic subs) get fitted with one of these - get their target orders, surface, open the can, fire, close the can, submerge until new target orders received....as an ex-surface guy I just messed myself a little with that scenario.
I would think the force is spread out over time more evenly than the more instaneous/reaction of an explosion, no?
Same reason an electric tram or streetcar will jerk you off your feet if it takes off too suddenly, yet still only reaches the same ultimate speed as if it had accelerated more evenly and smoothly... as perhaps this weapon is doing, building momentum in a linear fashion, not just one big KA-BOOM as one would have with a conventional explosive propellant
jmho
I would think the force is spread out over time more evenly than the relatively instaneous/reaction of an explosion, no?
Same reason an electric tram or streetcar will jerk you off your feet if it takes off too suddenly, yet still only reaches the same ultimate speed as if it had accelerated more evenly and smoothly... as perhaps this weapon is doing, building momentum in a linear fashion, not just one big KA-BOOM as one would have with a conventional explosive propellant
jmho
Mach 7 in what distance? The recoil will be significant because the gun is not really that long. Remember, 16-ich guns on battleships were long, but recoiled smartly nevertheless.
Big naval guns have been known to have a mechanism that fires them in sync with the ship’s instantaneous pitch; that is, at the instant that the pitch gives the angle of the barrel for which the firing solution was calculated.
With a railgun, you may even be able to near-instantaneously choose the amount of impulse to be given the projectile, thus fine-tuning the firing solution.
≤}B^)
From what I understand, I don't think those conventional formulae would apply here, although in fact, Newton's Third Law still applies.
In a typical firearm, the combustion of the powder is channeled to propel a bullet down a strictly defined path (i.e., the barrel). There is an "equal and opposite" reaction in which the rifle moves with equal force against the shooter's shoulder.
As I understand it the rail gun is more akin to a slingshot where the launching of the projectile is actually the "reaction." In a slingshot, the "action" occurs when energy is expended to draw the elastic. That energy is stored until released at which time the "reaction" propels the projectile forward. Similarly, a rail gun stores up electromagnetic energy, which is released in the launch of the projectile.
That's the way I understand it, but if I'm wrong, I'm sure there will be numerous others here who will correct me :-)
The Chinese will have this technology before Obammy leaves the office.
Good question
It is striking the seeming lack of recoil in the video, tho... maybe the thing is bolted down into a mile of bedrock
Those formulas do indeed apply here, as they are all related to the Newtonian Principles. Assume that the railgun has mass of its own and is well anchored.
Even electric motors have kickback. Try this for yourself: Get a small toy DC motor, and connect it to two leads. Lay the motor on a table so that it is free to move. Touch the wires to a battery, and observe that the motor jumps on the table as its housing rotates in the opposite direction to the shaft. That is evidence of a counterforce to the magnetic force that moves the armature. The railgun is a linear electric motor, and follows the same rules.
That is not strictly true. The bullet is accelerated by the pressure according to the formula F = ma, a = F/m. It reaches a final velocity proportional to the length of the barrel and the force exerted by the pressure. The pressure is not steady throughout the acceleration because the powder does not burn all at once and the volume of the hot gas increases as the bullet travels down the barrel exposing more bore space to the hot gasses. (Calculus must be used because the pressure and volumes are not constant.) The bullet is fully accelerated as it leaves the barrel, and its momentum is expressed as "M = mv". The rifle experiences the exact same momentum in the opposite direction, however it is more massive than the bullet. The rifle and its operator do not achieve anywhere near the same velocity just because of their higher mass. There is a bit more momentum imparted to the rifle as the high pressure gas is vented out the muzzel.
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