A solution to inhomogeneous 3D railgun

In a railgun, which is used to accelerate objects, electrical energy is used to drive the system. In order to reach hypervelocity, a power supply with an immense amount of energy must be used which causes an extra ordinary current on the rail and the armature. This current makes thermal energy by ohmic attenuation and warms up various points and therefore changes the electrical, thermal and mechanical specifications of the structure. This paper presents a method by which one can consider the inhomogeneity created by temperature changes along the structure. In this method, the instantaneous current distribution in the structure and the heat caused by it are calculated, and then the temperature distribution is obtained. The electrical conductivity (/spl sigma/), thermal conductivity (k) and specific heat (c) are considered to be inhomogeneous and are calculated at every instant until the specifications of the material forming the structure can be corrected at any instant. A three dimensional finite element method with nonuniform meshing at any instant is used.