ВИЗНАЧЕННЯ КРИТИЧНИХ РЕЖИМІВ РОЗВИТКУ ПРОЦЕСІВ ГОРІННЯ ПІРОТЕХНІЧНИХ НІТРАТНО-МЕТАЛЕВИХ СУМІШЕЙ В УМОВАХ ЗОВНІШНІХ ТЕРМІЧНИХ ДІЙ

Abstract

Currently, models of combustion of mixtures based on Mg + NaNO3 have been developed and investigated in detail to calculate the combustion rates of pyrotechnic mixtures. As for other pyrotechnic mixtures, the results of theoretical studies on the modeling of their combustion processes under different external conditions are very limited, and in most cases absent. The purpose of this work is to develop a model of combustion of compacted mixtures of Ti powders and nitrate-containing oxidizing agent (NaNO3, Ba(NO3)2, Sr(NO3)2) to determine the critical modes of their persecution by calculating the dependence of the propagation of the combustion front on charges and technological factors conditions. Developed mathematical model of combustion of pyrotechnic nitrate-metal mixtures allows to determine with accuracy of 8… 10 % the influence of high heating temperatures and external pressures (for a wide range of change of component ratios and dispersion) on the stage of design and subsequent bench testing of pyrotechnic articles with precision and dispersion, sustainable propagation of combustion in conditions of thermal impact. This makes it possible to predict different fire situations that occur in the external thermodynamic conditions to which the products are exposed during their operation. The mechanism is established and mathematical models of the pyrotechnic nitratemetal combustion process are used, which use kinetic characteristics of the processes of thermal decomposition of oxidizer, high-temperature oxidation, ignition and combustion of metal fuel particles on the combustion surface of the mixtures. The example of nitrate-titanium mixtures shows that models with a relative error of 8…10 % allow to determine the dependence of the rate of development of the combustion process of the mixture on the parameters of external thermal actions (increased heating temperatures and external pressures) for different values of their technological parameters (the ratio of components and dispersion), which makes it possible to find critical modes of combustion, the excess of which leads to the explosive destruction of pyrotechnic articles.