Inductance Gradient Calculations of EMFY-3 Electromagnetic Launcher

ASELSAN Inc. has been working on electromagnetic launch technologies since 2014. The first prototype, EMFY-1, has a 25 mm × 25 mm square bore and 3-m-length rails. The second prototype, EMFY-2, has a 50 × 50 mm square bore and 3-m-length. In this paper, a recently developed prototype, EMFY-3, is presented, which has a 50 × 75 mm rectangular bore and 6-m-length. The input energy of the PPS is doubled to 8 MJ, and the 2.91 MJ muzzle energy is obtained up to now. Rail currents, breech, and muzzle voltages are measured to investigate electromagnetic calculations. Velocity curves are captured with Doppler radar, which enables us to establish propulsive inductance gradient L0pr transients empirically. The results confirm that L0 pr is constant throughout the launch, as no significant breaking mechanism occurs with the non-magnetic containment. However, a slight variation (%2 at maximum) happens from one launch to another with different rails’ current magnitudes. The transition phenomenon is a candidate for the drop in the L0 pr, as it occurs more likely at launches with higher linear current densities.