Heat Generation During the Firing of a Capacitor-Based Railgun System

Railguns use a high-current, high-energy electrical pulse to accelerate projectiles to hypersonic velocities. Pulse-forming networks that employ capacitors as the energy store are typically used to shape the required electrical pulse. A significant fraction of the stored energy (2% to 40% in large caliber railguns) is converted to projectile kinetic energy during launch. After the projectile exits the launcher, the balance of the energy has either been dissipated as heat in the circuit components or is stored in system inductance. If an energy recovery scheme is not employed, the inductor energy will also be dissipated in the resistance of the active circuit components. A circuit analysis has been performed in order to calculate the current profile from the PFN. A higher fidelity solution was achieved by accounting for the temperature dependent resistance of the rails. This information along with individual component resistance and inductance was used to calculate the distribution of energy subsequent to a single pulse. Detailed component heating information is important when considering the overall thermal management of the system. Once this information has been obtained, the components that require external cooling can be identified, and an appropriate thermal management system can in turn be designed