Simulation and Optimization of the Multi-Stage Reconnection Electromagnetic Launch

The reconnection electromagnetic launcher utilizes the interaction between the projectile eddy current and the coil magnetic field to accelerate the projectile. A reconnection launch experimental system using the box-shaped helical coils and the flat-plate projectile has been fabricated. Capacitor banks are used as the power supplies. The inductance gradient curve-fitting is performed on the basis of the measured data from the launch apparatus. Based on the circuit equation and the motion equation of the reconnection electromagnetic launch, the numerical simulation model of the projectile motion is established. The simulations show that the launch efficiency decreases when the projectile velocity increases in the multi-stage launch if every stage is kept with the same parameters. To solve the problem, an optimization for the multi-stage launch is presented. The oscillating cycle of the circuit current in each stage is determined according to the projectile velocity, from which the capacitance of the capacitor bank is determined further. Combined with the use of triggered vacuum switches (TVS) as closing switches and owing to the special arc extinguishing performance of the TVS, the projectile velocity can be increased and the launch efficiency can be improved greatly.