Simulation, verification, and prediction of thermal response of bridgewire in electro-explosive device

The thermal response of electro-explosive device (EED) is commonly used for product design, non-destructive testing, and analysis of electromagnetic susceptibility, etc. The bridgewire (BW) is the core of EED, and its thermal response determines the thermal response of EED. In this article, an electric-thermal model of BW in BW EED under dc heating is established using COMSOL, and verified through experiments using a self-built experimental apparatus, which mainly consists of a dc heating part and a resistance measurement part. The simulation model combines the electrical and thermal physical fields. The simulated temperature rise of BW is close to the experimental result, verifying the accuracy of the established model. The heat loss factor and thermal time constant are calculated using the measured and simulated results to analyze the difference between simulation and experiment. The influences of material, radius, and length of BW on the thermal response of BW are analyzed using the established simulation model. Under the same current, the temperature rise of Cr20Ni80, SS 304, PtW, and Pt BWs decreases sequentially, and the thermal time constants of Cr20Ni80 and SS 304 BWs are far greater than those of PtW and Pt BWs. As the radius of BW increases, the temperature rise of BW decreases, while the thermal time constant of BW changes little. As the length of BW increases, the temperature rise and thermal time constant of BW both increase.