Numerical Simulation And Thermal Damage Assessment On Explosion In Air

Relative to the current mature study on the shock wave of explosive, the thermal effect has not been sufficient. It also made the understanding of multi-factor destruction of explosives and explosion, the coupling between the factors and the explosion total damaging effects was not comprehensive and systematic. To achieve this purpose, the explosive thermal effects should be comprehensively analyzed and numerically simulated.Firstly, starting from the nature of the thermal radiation, the characteristics of fireball heat radiation were discussed, the existing fireball theoretical model was summarized in the aspect of the morphology parameters such as explosion fireball diameter and duration and thermal parameters such as heat flux and thermal dose, and blasting heat, fireball temperature and fireball diameter were calculated by the composition of dynamite.Secondly, explosion of conventional high explosives and composite aluminum-containing explosives in air were numerically simulated in one-dimension and two-dimension by using AUTODYN-a numerical simulation software. Air overpressure, positive pressure time, explosion temperature and explosion fireball expansion process were acquired, and above-mentioned were compared to the results of empirical formula calculation and related experiments. Comparing to conventional high explosive TNT, blast overpressure attenuation of composite aluminized explosive had a relatively long duration of the positive pressure zone due to the afterburning effect. By comparing the numerical simulation of explosive thermal field with the experimental results by the analysis and the observation of dispersal process photographed by high-speed motion photography of high explosives and composite aluminized explosive detonation products, the numerical simulation work of explosions thermal field had a fairly good degree of compliance.Finally, applicable thermal effects testing system, which can determine the thermal radiation effect of the explosive charge blast field (EBF) directly, was built in this paper. This system can acquire the datadraw of EBF thermal radiation effects within the range of explosive charge mass from one hundred grams to kilogram and the law of blast field thermal radiation effects and influencing factors by studying two kinds of typical explosives in the law of their EBF thermal effect. Heat damage effect of high explosives and composite aluminum-containing explosive were assessed by thermal damage criteria.