Research on the Sliding Electrical Contact of the Rapid Fire Railgun

Abstract

The sliding electrical contact between the armature and the rails is affected by the high driving current and the friction heating during the launching process, especially in high fire rate applications. The contact performance is closely related to the impedance between the armature and the rails. A rapid fire railgun was designed for this paper of the sliding electrical contact. The pulsed power system consists of ten 100 kJ pulse forming units with a total stored energy of 1 MJ, and the length of the launcher is 1310 mm with a caliber size of 18 $\,\times\,$ 18 mm. Two types of armatures are adopted, a C-shaped armature and a double C-shaped armature. Two 5 g armatures can be launched at a frequency of 166 Hz with a muzzle speed of 800 m/s. The effect of contact impedance by the temperature rise can be calculated approximately with heating. Experimental results show that the contact impedance is seriously affected by the electromagnetic force and the contact temperature; the contact impedance of the second armature is 0.8–2.6 ${\rm m}\Omega$ , which is higher than that of the first armature (0.2–0.3 ${\rm m}\Omega$ ).