Ignition and combustion of pyrotechnic compositions based on microsized and ultra-nanosized aluminum particles in a moist medium in a two-zone gas generator

This paper presents the results of an experimental study of the ignition and combustion of pyrotechnic compositions based on microsized and ultra-nanosized aluminum particles in a model two-zone gas generator in which water is supplied as the oxidizer. The flow of the combustion products from the gas generator was video recorded, and the condensed products sampled behind the nozzle exit were studied by chemical and grain-size analysis. It was found that the replacement of aluminum microsized particles by ultra-nanosized particles in the samples led to $\approx$ 17% decrease in the active aluminum content in the condensed phase, a 10–15% increase in the efficiency of the process in the gas generator (completeness of conversion of the pyrotechnic composition to the combustion products), and a factor of about three decrease in the ignition delay.