Characterization of display pyrotechnic propellants: Burning rate

The combustion of display pyrotechnic propellants utilized for producing colored light has been studied. The linear burning rates of cylindrical propellant strands were measured using high-speed videography. The experiments were conducted with air at atmospheric pressure as the surrounding medium mimicking the conditions of unconfined aerial combustion typically encountered for these propellants. Five different formulations of display pyrotechnic propellants producing red, green, blue, yellow, and silver color were tested. The flame zone was observed to be situated very close to the propellant surface and the colored flame extended beyond this point. The phenomenology of the combustion process was explained and the combustion process was also studied numerically using a methodology based on the deflagration rate law. The experimentally measured burning rates were utilized in the deflagration rate law to obtain the simulation parameters which may be utilized in hydrocodes for performance prediction and simulation pyrotechnic propellant applications.