Experimental And Numerical Research On Thermal Security Of Ammunition In Fire

On the battlefield or in the daily storage or transport, there is a great risk for ammunition since it has a certain degree of sense for thermal stimulation. In order to study the risk of artillery shell under heat environment, this thesis experimented and simulated cook-off test of the metal cartridge with charge in fire, and got the propellant’s temperature changes, deflagration point and the time of deflagration. Furthermore, the termal analysis and thermal hazard evaluation of RDX which is picked as the representative of expolsive had been done to study the thermal hazards of projectile.The work of this thesis is summarized as following:Using gypsum powder substitute propellant to experiment and research the temperature curves, the maximum temperature point and the point’s time when propellant get ignited of 122 mm steel cartridge with charge and 152 mm brass cartridge with charge under different heat flux through cook-off test, we obtained the temperature distribution of metal cartridge with charge and the law of time that propellant get ignited with the increase of heat flux. Then we compared two cook-off tests of 122 mm steel cartridge and 152 mm brass cartridge.The cook-off simulation of 122 mm steel cartridge and 152 mm brass cartridge with gypsum powder as well as propellant in each heat flux have been done by using FLUENT software. Compared with the experiment result, we got a better result. The cook-off simulation result is conservative, which from the point of controlling the risk of heat, it is reasonable to use simulation result as reference value. Through the cook-off simulation of 122 mm steel cartridge with 9/7 propellant and 152 mm brass cartridge with 9/7 propellant, we obtained the deflagration point, deflagration temperature, deflagration time of the propellant and the law of deflagration time and temperature with the increasement of heat flux. By comparing the result of metal cartridge with gypsum and 9/7 propellant, we discovered that although the heating rate is fast, the self-heating reaction still has great influence on deflagration time. Furthermore, we found it is not the same influence to the deflagration time of metal cartridge with propellant by increase the same heat flux.Thermal analysis and thermal hazard evaluation of RDX has been done by mean of simulataneous TG-DSC apparatus. The commonness and difference of RDX’s thermal decomposition reaction under four different heating rates has been obtained. We got RDX’s "kinetic triplet" by means of multiple scanning method and thermal explosion critical temperature and SADT through the chemical substance thermal hazard evaluation. The high critical temperature of thermal explosion and SADT indicates that RDX has good thermal safety and is less prone to thermal decomposition at normal temperature.