Advanced Rail-Sabot Configurations for Brush Armatures

Abstract

This paper reports on experimental results obtained at the ISL-railgun facility EMA3 (muzzle velocity 0 2 km/s, applied energy per shot prim 1 MJ, = 3 m, regular cal. = 15 mm 30 mm, (multiple) metal fiber brush armatures) from 2001 to 2005. Several techniques with the aim of investigating contact performance up to 2 km/s were developed during this period. These techniques include: 1) quasi-segmented and wedge shaped rail configurations, which vary the width of the rail as a function of the rail length in order to maximize the performance of multiple brush armatures; 2) separating sabot technique, for which the latest experimental results and some calculated figures of merit based on a simple model are presented; and 3) new contact materials for solving the problem of gouging at very high contact transition velocities. Some experimental results obtained with brush armatures are presented. The paper concludes by presenting detailed results of a representative shot combining all of the mentioned techniques and clearly demonstrating their capacities. A lower limit of the contact transition velocity of 1800 m/s has been observed, increasing the previously observed value of 1100 m/s significantly.

The ISL Rapid Fire Railgun Project RAFIRA—Part II: First Results

“…It consists of metal fiber brush armatures incorporated into a sabot of GRP. Various brush configurations were tested, and in particular, the technique of using a separating sabot was introduced in order to increase the muzzle velocity by reducing parasitic mass [8]. The brushes have an initial length greater than the distance between the rails leading to a "mass reservoir" which can be worn out before the contact loss must occur.…”

Measurement of the Magnetic Field Distribution in Railguns Using CMR-B-Scalar Sensors

“…Static railgun experiments were performed by short--circuiting the 1370-mm-long EMA3-type railgun [3]. It consisted of copper-chrome rails with a conductivity σ = 5 × 10 7 S/m and a mechanical setup made from steel and glass fibre reinforced plastics (GRP).…”

The ISL Rapid Fire Railgun Project RAFIRA Part II: First Results

“…It consists of metal fiber brush armatures incorporated into a sabot of GRP. Various brush configurations were tested and in particular the technique of using a separating sabot was introduced in order to increase the muzzle velocity by reducing parasitic mass [8]. The brushes have an initial length lb greater than the distance between the rails d leading to a "mass reservoir" (lb-d) which can be worn out before the contact loss must occur.…”