Effect of Aluminum Particle Size on the Explosion Parameters of HMX-based Thermobaric Explosives in Confined Space

To study the effect of aluminum particle size on the explosion parameters of HMX-based thermobaric explosive in confined space, the explosion test was carried out for the HMX-based thermobaric explosive with aluminum particle median diameters (D50) of 2.7μm (Formula 1), 5.4μm (Formula 2), 23.8μm (Formula 3) and 96.9μm (Formula 4). The reflected wave overpressure curve was measured in a spherical explosion tank device by a pressure test system. The explosion energy releasing characteristics was analyzed according to five characteristic parameters of reflected wave overpressure peak, impulse, quasi-static pressure, rise time of quasi-static pressure and pressure decay coefficient. The results show that with increasing the particle size of aluminum powder, the reflected wave overpressure and impulse increase at first and then decrease. The overpressure and impulse of the reflection wave are the largest for Formula 2, which are 13% and 7.4% higher than those of Formula 1, 35.6% and 16.8% higher than those of Formula 3, 47.8% and 32.7% higher than those of Formula 4, respectively; When the particle size of aluminum powder is 5.4μm, the quasi-static pressure pQS is the highest, 3.9% higher than that of Formula 1, 1.8% higher than that of Formula 3 and 1.6% higher than that of Formula 4 respectively; the rising time of quasi-static pressure decreases as Formula 1 Formula 2>Formula 3>Formula 4,showing that the particle size of aluminum powder has great influence on the reflected wave pressure and quasi-static pressure. © 2020, Editorial Board of Journal of Explosives & Propellants. All right reserved.