&nbsp; &nbsp; This paper provides an overview of railguns that introduces basic theory, component design, improved configurations, and applications. Railguns are electric weapons that generate an electromagnetic force to propel a projectile at velocities significantly greater than guns using chemical propellants. The high velocities achieved by railguns increase kinetic energy of the projectile, improve range, and eliminating the need to store dangerous, heavy propellants.&nbsp; The weapon consists of two parallel conductive rails and a conductive armature that rides between both rails. Current flows up the first rail, across an armature, and returns down the second, parallel rail. A magnetic field is generated between the rails as the current flows through the system. The Lorentz force generated by the magnetic field acts perpendicularly to both the current and magnetic field. This results in the parallel rails being pushed outwards and the armature being driven along the rails. A large current applied generates the field strength and force to propel the armature and projectile to a high velocity.&nbsp; &nbsp; Railguns face design challenges&nbsp;that have kept them wide-spread employment.&nbsp; They require conductive material to efficiently transmit several million amperes of current.&nbsp; Additionally, the system must survive significant heat generation, mechanical shock, and high loads.&nbsp; Because of the electrical draw, railguns are attractive for use on naval ships that have a robust on-board power source. Other challenges presented in the development of the railgun include the requirement for the system to handle large mechanical and thermal shocks. Types of damage include physical deformation of the rail surface, called gouging, which is caused by the armature moving at high velocities along the rails. Grooving occurs on both sides of the rail and is caused by thermal stresses. Transition and arc ablation is another failure mode where the armature creates a plasma arc between the armature and the rail. This paper addresses the material selection and design of the containment structure necessary to overcome the above failure modes.&nbsp; &nbsp; &nbsp;There are different configurations of the railgun in development to include the multiple railgun, parallel railgun, and augmented railgun. The multiple railgun utilizes more than two rails to propel a projectile. This configuration allows for a more symmetric pressure system in the weapon when firing and could be applied when firing projectiles with sensitive electronics. The parallel railgun uses four independent railguns in one system with the hope of creating a weapon that can launch larger projectiles. The augmented railgun employs augmented rails in the system with the goal of accelerating a projectile with a lower current running through the weapon. Like the simple railgun, the improved designs currently proposed rely on the Lorentz force of a generated magnetic field to propel the armature and projectile. A final section discusses the future technologies and advancements necessary to overcome the issues present in current designs.&nbsp;

Railguns: An Overview

Paper Proceedings: https://asmedigitalcollection.asme.org/IMECE/IMECE2021/volume/85543

ASME 2021 International Mechanical Engineering Congress and Exposition (IMECE2021)

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