Field-Circuit Coupled Analysis of a Series-Augmented Electromagnetic Railgun

A field-circuit coupled algorithm was developed to model the circuit behaviors and electromagnetic-field details of electromagnetic railguns. The railgun launcher was described by a 3-D transient eddy current field model with the electric current as the exciting source. The launcher was also treated as an RL series load of an external circuit composed of capacitor-based pulse forming networks. The variable resistance and inductance of the launcher were calculated by the electromagnetic field results, and the field-circuit coupling was achieved by matching the current, resistance, and inductance in both the external circuit and the launcher. The algorithm was partly verified by experiments of a two-turn series-augmented railgun system. The full dynamic numerical results, such as the current and voltage histories, transient load characteristics, and time evolution of electromagnetic field, provided a deep insight on the launching process of the augmented railgun.