Study on the effects of combustion characteristics of pyrotechnic charges on pyrotechnic shocks

This study calculates the combustion characteristics of various gas-generating and micro gas pyrotechnic charges, including aluminium/potassium perchlorate, boron/potassium nitrate, carbon black/potassium nitrate, and silicon-based delay compositions, using thermodynamic software. A multiphase flow-thermal-solid coupling model was established, and the combustion process of the pyrotechnic charges within a closed bomb was simulated. The pyrotechnic shock generated by combustion was predicted. The combustion pressures and pyrotechnic shocks were measured. The simulation results demonstrated good agreement with experimental results. Additionally, the mechanism of shock generation by the combustion of pyrotechnic charges in the closed bomb was analyzed. The effects of the combustion characteristics of the pyrotechnic charges on the resulting pyrotechnic shocks were systematically investigated. Notably, the shock response spectrum of the gas-generating pyrotechnic charges is greater than that of the micro gas compositions at most frequencies, particularly in the mid-field pyrotechnic shocks (3–10 kHz). Furthermore, the pyrotechnic shocks increase approximately linearly with the impulse of the gas-generating pyrotechnic charges.