Influence of thermal decomposition kinetic model on results of propellants self-ignition numerical modeling

Description

15 p.New trends in research of energetic materials. Proceeding of the V. Seminar. Thermal decomposition of nitrocellulose propellants is accompanied by generation of heat, and under certain conditions can lead to the well-known phenomenon of the self-ignition. Therefore, it is of great concern to predict whether or not a propellant specimen will ignite under given conditions (specimen mass and shape, surrounding temperature, etc.). An own computer program, named THERMEX, based on the thermal explosion theory and the finite difference method, was developed in order to describe the reactive heat conduction phenomena in infinite slab, cylindrical, and spherical geometry of an explosive material. Up to now the program is tested by the comparison of the calculated times to ignition with the times to ignition experimentally obtained or calculated by other authors. A good agreement was found under identical computational conditions. However, it was noticed that, along with some input data (e.g. space and time increments), thermal decomposition kinetic model used in calculations have a large influence on the calculation results. The influence of three kinetic models, commonly used to describe thermal decomposition of propellants, on the results of calculation is analysed in this paper. It was found out that the power law kinetic model gives the best agreement between the experimentally obtained and the calculated values of times to ignition.