Numerical Simulation of the Heat Transfer in the Electric Hot Bridgewire Initiator

The electric initiator is an important component of the explosive train which provides requiered energy to initiate a chemical reaction by converting the electric current to the heat via a bridgewire. This initiator is widely used in the field of aerospace industry in the solid rocket propellant motors, separation systems and etc due to its low weight and high reliability. In this research, a mathematical model has been introduced to investigate the effective parameters on the electric initiator performance. Comparison of numerical simulation results by finite difference method and experimental data showed that this model has the ability of the prediction of the ignition time and determine the transient temperature profile in axial and radial direction. The model showed that the reduction of the contact heat transfer coefficient between the bridgewire and the primer compared to its increase has a greater effect on the heat transfer rate. It was also found that with increasing the current, the temperature changes decreased along the axial direction and increased in radial direction.