Study Of The Explosive Characteristics Of Certain Thermobaric Explosive

In this paper, the explosion characteristics of thermobaric explosive were studied. The following aspects were considered:detonation parameters, shock wave parameters under the condition of static detonation in opened space, shock wave characteristics in confined space.By means of computational and experimental research about detonation velocity and detonation pressure of thermobaric explosive, a reliable calculation method was obtained. Thermobaric explosive has both high energy explosives and volume cloud explosion characteristics by calculated results, in addition, the content of aluminum powder was higher, the detonation parameters were lower. According to the experimental data obtained by field tests to compare the shock wave parameters of thermobaric explosive and TNT, thermobaric explosive’s shock overpressure, duration time and impulse were higher than those of TNT in different distance; Comparing the shock wave parameters among thermobaric explosives which have different aluminum powder contents, it was satisfactory when the content of aluminum was30%. By virtue of explosion similar law, the power of thermobaric explosive estimated in TNT equivalence was1.76by using the overpressures. Under the test condition in this paper, the effective utilization of energy in the thermobaric explosive was65.41%, the combustible elements (Al, C, H) were not fully reaction. The shock wave pressure-time curve was divided into two parts to analyze by the static detonation test in confined space, the results show that the first one was generated before the shock reflection, the initial parameters and the variation were same with opened space; Another one is formed after the reflection, the shock wave parameter data showed that the duration time reached up to270ms or so, it was90-250times longer than the duration time of the head shock wave, what’s more, the highest whole impulse reached up to about4000Pa-s, which was20-200times as high as the impulse of head shock wave. Furthermore,6-17peaks were found in each p(t) curve.Numerical simulations are accomplished for the static detonation of thermobaric explosive in confined space by using AUTODYN, which is a finite element analysis program. Compared with the experimental results, the overpressure was lower, the duration time was higher while the impulse was consistent with the experimental results. Shock wave cloud image showed that within40ms, there were twice reflection in the sidewall surface, twice reflection on the top and twice focus in the space, the pressure of the focus point as high as4MPa. The curves with the arrival time of shock wave changed in distance and explosion fireball development curves indicated there was a interaction of shock wave and post-combustion reaction within5.3ms～5.8ms, afterburning decreased shock wave’s attenuation rate gradually, shock wave strengthened the combustion reaction, the explosive fireball radius reached to1.7m～2.1m.