Oxidizer effects on the near-ground explosion performance of hmx-based thermobaric explosives

In this paper, the effect of oxidizers on the near-ground explosion performance of HMX-based thermobaric explosives (charges' mass of 500 g) are studied by means of experiments and numerical calculations. The trajectory of the Mach triple point motion shows that its height dramatically increases above the incidence angle of 70$^{\circ}$C. The Mach stem exceeds the height of the explosion centre at a distance greater than 3.6 m. The experimental results show that the temperature distribution on the fireball surface is asymmetrical, and the temperature of the upper fireball is higher than that of the lower fireball. The peak temperature of the thermobaric explosive is higher than 2400 K, and the fireball temperature is above 400 K for nearly 1000 ms. The oxidizers, i.e., potassium perchlorate and Fe$_2$O$_3$ slightly enhance the overpressure of the incident wave and significantly prolong the barotropic duration. In addition, potassium perchlorate can quickly participate in the afterburning reaction, while polytetrafluoroethylene is less efficient. The energy released by the thermite reaction of Fe$_2$O$_3$ contributes to the maintenance of temperature, especially the late fireball temperature.