Ignition Characteristic of Bridgewire Electric Ignition Element in Limited Space

As a common ignition element, the ignition characteristic in limited space of a bridgewire electric ignition element (EIE) is the internal embodiment of its precision and reliability as an explosion-transfer sequence. The limited space environment of bridgewire electric fusehead ignition is simulated by preparing test samples and the test system of the ignition parameter is designed to test the time structure of the ignition process, the gas pressure, ignition light intensity and other parameters in limited space; using the high-speed camera to test the dynamic ignition process of the EIE, a physical model of ignition in the limited space of EIE is established. The research shows that with the increase of the ignition voltage, the phase transition time of the bridgewire is shortened, the duration of the plasma stage increases, and then tends to stabilize. The ignition time of the electric fusehead fluctuates at about 5.6 ms, and the ignition pressure time and the ignition light intensity time are maintained in the 3.0–5.0 ms range. After the ignition voltage reaches 20 V, the ignition characteristic parameters tend to be stable, and it can reliably output uniform ignition energy for igniting the next sequence of charging. In the limited space of the air chamber, the dynamic process of EIE can be divided into four stages: bridgewire heating up and heating fusehead agent, fusehead agent ignition, heat flow diffusion and shock wave reflection.