Study on the Propagation Law of the Shock Wave of Thermobaric Explosives under Different Initial Pressures

In order to study the influence of the initial ambient pressure on the explosion parameters of thermobaric explosives, static explosion experiments were conducted using TNT as a reference were carried out at both low and high initial ambient pressures. Different grades of thermobaric explosives were tested, and a correlation model was proposed to analyze the overpressure and impulse of the blast shock wave in different initial environments, taking into account the atmospheric pressure factor. A pressure acquisition system was utilized to obtain the blast shock wave parameters for analysis. The results indicate that the overall distribution and attenuation characteristics of the explosion shock waves of TNT and thermobaric explosives are basically the same under different initial ambient pressures. As the initial ambient pressure decreases, both shock wave overpressure and impulse decrease. The blast propagation velocity, blast overpressure and momentum also decrease with the decrease of initial ambient pressures. Furthermore, as the mass of the explosives increases, the decreases in overpressure and impulse decrease for both thermobaric explosives and TNT, and the difference in the amount of change in blast propagation velocity between the two types of explosives also decrease. The correlation model, when compared to experimental data, yielded average maximum relative errors of 12.3% for TNT and 8.8% for thermobaric explosives in low pressure environments regarding shockwave overpressure. And for impulse, the respective errors were 12% for TNT and 13.7% for thermobaric explosives. These results indicate that the correlation model has a high degree of accuracy. By using this correlation model, the overpressure and impulse of the blast shockwave can be obtained under different initial ambient pressures, providing a basis for assessing the shockwave power generated by thermobaric explosives at different initial ambient pressures.