A Comparison of C-Shaped and Brush Armature Performance

Abstract

The most important part of a railgun launch package is the armature where the electromagnetic force is generated leading to the acceleration of the launch package. In case of metal armatures, the most commonly used armature types are the C-shape and the multi-fiber brush technology. However, rarely both armature types were systematically compared under similar experimental conditions. That is why we constructed launch packages based on the C-shaped and brush armature technology with comparable armature and payload mass. With these launch packages a series of experiments were performed in an energy range between 0.8 MJ and 1.13 MJ corresponding to a speed range between 950 m/s and 1400 m/s. The results of the experiments were then analyzed qualitatively and quantitatively. On the one hand our results show that the total losses are higher for the C-shaped armature technology than for the brush aramture technology. On the other hand our results show that launch packages based on the C-shaped technology convert better electrical energy into kinetic energy.

Numerical 3D Simulation of a Full System Air Core Compulsator-Electromagnetic Rail Launcher

“…The reported waveforms put into evidence the uneven current density distribution in the rail section for most of the launch time, the ratio between the maximum and the minimum value is greater than two. This behavior is a consequence of the skin and proximity effects; also, the velocity skin effect has an heavy impact on the current distribution, which is a function of the rate of change of the electrical quantities imposed by the generator and the rate of change of the mechanical quantities i.e., the speed of the armature [36,37]. Both these quantities change during the launch.…”

Demonstration of a 1 MJ XRAM Generator Supplying a Medium Caliber Railgun

“…The railgun facility RAFIRA was chosen for experimental investigations because it has served for many experiments in the energy range around 1 MJ [53]. Thus, it allows us to compare experimental results with old recordings.…”

Magnetomechanical study of open-bore two-rail electromagnetic launcher

“…The C-shape armature is very difficult to vary parameters during the experiments (Stefani and Parker 1999). b) is the brush armatures (Wild et al 2017) In literature, it is possible to find the investigations of solid cube armature. The solid cube armature is convenient to investigate the EM effects distribution in EM launcher construction.…”