Novel Study of the Rail’s Geometry in the Electromagnetic Launcher

This paper proposed a railgun with sector of circular rails. The center of the sector of circular rails is located at the outside of the railgun bore. The distance between the sectors of two circles is s , opening angle facing outward θ, the inner and outer radius are also assumed to be R_i and R_o, respectively. The influence of internal curvature of the rails, the rail thickness and the distance between rails on the current density, magnetic flux density, and inductance gradient (L´) have been studied and analyzed using finite-element method. First of all, the different values of θ, s, R_i, and R_o are calculated for various values of the area of the railgun bore (S_C) and cross section of the rails (S_R). The current density, magnetic flux density, and L´ have been calculated for different values. The area of the railgun bore is assumed to be 9 and 10 cm² and the area of rails are assumed to be 9, 6, 3, and 1 cm². In next section, L´ is found as a function of s, R_i, and R_o for θ =90°, 120°, 150°, and 180°. Finally, L´ is compute for rail thickness equals to one-tenth of bore size and θ on the interval [180°, 360°]. According to the achieved results it can be observed the behavior of L´ in terms of railgun dimensions changes and it is compared with other geometries.