Skip to main content

Railguns

Since the 1950s, railguns along with other electromagnetic projectile devices have dominated the science fiction scene and the human imagination. Sadly, these railguns depicted in literature and film do not behave like a real-life railgun which in their current iteration are much larger and less powerful than those depicted in fiction. The first appearance of a device which works similar to a modern railgun was in 1918 when the French inventor Louis Octave Fauchon-Villeplee created an electric cannon to propel projectiles. The idea also popped up during WWII when a German Ordnance officer developed the first “true” or theoretically reliable railgun for use as a electric anti air gun. Following the war, the US discovered the theory among the papers seized from the German Reich and attempted to work on the concept. The project was restarted in the early 2000s and currently the US Navy has made great progress on making an extremely powerful railgun.
A railgun does not use any sort of permanent magnets or traditional electric motors instead the basic form is formed by a single loop of current which passes through the projectile. This causes the gun to require immense amounts of power to produce the needed muzzle velocities to weaponize the device. This means that for the time being railguns will only be able to be used as weapons on major U.S. Navy ships with the extra electrical capacity to power the gun. A railgun consists of two metal rails which are parallel to each other which is then attached to a power supply. When a projectile made out of a conductive metal is placed in the gun, electrons flow from the negative terminal through the negative rail, across the projectile and then back to the power supply in positive rail. This makes the railgun behave similar to an electromagnet causing the projectile to be accelerated along the rails. The magnetic fields from the parallel rails point in the same direction create a magnetic field strong enough to propel the projectile out of the gun with the current away from the power supply.
Kinematics Analysis:

X
Y
Delta position
370,400 meters
0 meters
Initial velocity
2,520 m/s

Final Velocity
2,520 m/s
1715 m/s
Acceleration


Time
360 secs
360 secs
         
152,400 meters at highest point(aka halfway)
Therefore x=370,400 / 2
x= 185,200
Create a triangle and use arctangent to find out angle to fire the gun
Tan-1 = Y / X
Tan-1 = 152,400 / 185,200
Ï´= 39.5 degrees

X
Y
Delta position
370,400 meters
0 meters
Initial velocity
39.5 * cos * (2,520 m/s)
39.5* sin (2,520 m/s)
Final Velocity
39.5 * cos * (2,520 m/s)
1715 m/s
Acceleration
0
-9.8 m/s2
Time
360 secs
360 secs

This analysis shows that railguns will be extremely effective weapons especially compared to conventional weaponry in a similar position. For comparison, the 5 inch gun mounted on most US Navy ships will be used. The muzzle velocity of this weapon is 762 m/s which is about three times slower than the rail gun's muzzle velocity of 2,520 m/s. This gives the railgun the ability to blindside enemy vessels in direct fire range hitting enemy vessels in 6 seconds with an immense amount of force, ripping holes deep into the ship. Due to incredible accuracy caused by the length of barrel, the railgun could theoretically knockout individual modules of an enemy ship in a single shot, including ammunition magazines and engines. The five inch gun used by the US Navy also has a effective range of 13 nautical miles which is greatly out ranged by a railguns estimated 100-200 nautical miles. This allows the ship to open up with the railgun at extreme ranges to sink enemy ships and stop cruise missiles which typically travel on a straight line very far from the ship. Finally a railgun projectile is non-explosive allowing a ship to have very few if any explosives onboard making the ship much safer.     
This image from the US Navy was used to calculate my kinemactics.

Video from the US Navy showcasing their railgun firing multi-shot bursts showcasing a major step in making a viable weapon. 

VPython Program showing the force on a wire
(Cyan arrows are the magnetic fields from the rails,
the red arrows are the path of the electrical current,
gray arrow is the force vector) (Wired)



Comments

Post a Comment

Popular posts from this blog

Physics of Sound Dampeners and Active Noise Cancellation

Physics of Sound Dampeners and Active Noise Cancellation Sound dampening foam panels in a recording studio. ANC headphones worn by pilots and/or passengers in consumer aviation aircraft.  Acoustic treatment of soundscapes has grown alongside the sound production industry. Whether through absorption panels, diffusors and cloud panels to treat a space or headphones placed directly over the ears of listeners, acoustic treatment comes in many forms. Environments are treated acoustically to absorb excess sound to prevent sound levels from crossing a threshold above which the desired goal cannot be had. Before getting into sound dampening, we must discuss sound. Sound is produced when an object vibrates (a form of oscillation) and temporarily displaces nearby air molecules causing a wave effect as the displaced molecules collide with their neighboring molecules. Sound waves are fluctuations in pressure as the initial displacement of molecules experiences collisions that in ...
Post a Comment
Read more

Large Hadron Collider

The Large Hadron Collider (LHC) is the world’s largest and most powerful particle accelerator. The LHC is the largest machine in the world. It took thousands of scientists, engineers and technicians decades to plan and build, and it continues to operate at the very boundaries of scientific knowledge. It first started up on 10 September 2008, and remains the latest addition to CERN’s accelerator complex. The LHC consists of a 27-kilometre ring of superconducting magnets with a number of accelerating structures to boost the energy of the particles along the way. Map of LHC (located in Geneva, Switzerland) Thousands of magnets of different varieties and sizes are used to direct the beams around the accelerator.  Just prior to collision, another type of magnet is used to "squeeze" the particles closer together to increase the chances of collisions. The particles are so tiny that the task of making them collide is akin to firing two needles 10 kilometres apart with suc...
Post a Comment
Read more

Aerodynamics of a Golf Ball

One may wonder how a small golf ball can travel at incredibly high speeds for such long distances.  While the swing of the club is a major component, the structure of the golf ball is quite important.  Unlike a baseball or tennis ball, a golf ball has dimples all over it (usually 336 dimples).  These dimples allow the golf ball to travel without facing much air resistance.  This diagram shows how air travels around the golf ball. The dimples on the golf ball also prevent drag that would occur in the wake region, resulting in further distance.  Also due to the contact with the club during the swing, the golf ball has backspin during its entire flight.  This diagram shows the motion of the golf ball mid flight with the lift force of F. There are hundreds of different types of golf balls that a player can choose.  Some show little affect to a player's game while others can alter their performance completely.  Personally, I prefer Callaway Supers...
Post a Comment
Read more