Efficiency Scaling for Railgun Armatures

摘要

The results of a numerical study on three hypervelocity railgun armature options are presented in this paper. The armatures considered are the plasma, the hybrid, and the transitioning armatures. Several scaling studies are presented which illustrate the sensitivity of armature performance to variations in various railgun parameters. Armature performance scaling with projectile velocity, bore size (projectile mass), and current per unit rail height are all examined. An interesting conclusion of these studies is that armature efficiency tends to improve with increasing bore size. Also, results are presented from studies which determine how armature performance scales with uncertain parameters such as the ablation entrainment fraction, the skin coefficient, and the contact potential. These studies indicate which parameters have the greatest impact on armature performance and, therefore, need to be determined more accurately to predict railgun performance.