快速热点火熔奥梯铝炸药燃烧转爆轰实验研究

以熔铸型含铝混合炸药熔奥梯铝为对象,研究铸装含铝混合炸药快速热点火后的燃烧转爆轰特性。建立了快速热点火燃烧转爆轰实验平台,由实验装置(加热装置、约束钢管、炸药)、压力测试系统、光纤测速系统组成;加热装置加热15 mm厚45钢钢板,峰值温度大于1 100℃,温升速率为85～95℃/s。开展了快速热点火带壳熔奥梯铝炸药燃烧转爆轰实验,由加热装置加热约束钢管内熔奥梯铝炸药,炸药化学反应阵面压力和传播速度分别由压电性高压压力传感器和光纤探针测定;实测阵面压力约1 GPa,传播速度最大约2 600 m/s。由光纤数据获得炸药化学反应阵面传播轨迹,通过特征线方法获得冲击形成点,半定量给出冲击形成距离大于850 mm;并比较了管体破片质量实测值与炸药完全爆轰时破片平均质量计算值,实测值远小于计算值。综合实测化学反应阵面传播速度和压力、冲击形成距离分析、破片质量比较,可确定熔奥梯铝炸药没有发生完全爆轰,其化学反应状态为爆燃。另外,采用Adams和Pack模型、CJ燃烧模型,都能够半定量的预估冲击形成距离和燃烧波后压力,为实验设计提供依据,但CJ燃烧模型的计算结果更接近于实测值。

Experimental investigation on deflagration to detonation transition of HMX/TNT/AL compositions at fast thermal ignition

Cast HMX/TNT/AL compositions are an aluminized explosive. In the present investigation of the deflagration to detonation transition of the cast HMX/TNT/AL compositions with a metal shell at fast thermal ignition, we constructed an experimental platform of DDT of the explosives with a metal shell at fast thermal ignition, which was composed of an experimental equipment, a pressure testing system and a fiber probe system used in the velocity measure. The experimental equipment was composed of the fast heating equipment, the steel tube and the explosives. The peak temperatures were more than 1 100 °C, the temperature rise ranged from 85 °C/s to 95 °C/s when the steel plates 16 mm chick were heated up by the fast heating equipment. Experiments on DDT of the explosives were conducted in which the cast HMX/TNT/AL compositions in the steel tube was heated up using the fast heating equipment. The velocity of the chemical reaction front was measured by the fiber probe as less than 2 600 m/s. The pressure of the chemical reaction front was measured by the high pressure sensor as approximately 1 GPa. The track of the chemical reaction front was obtained using the fiber history. The vicinity and distance of the shock formation were obtained through the characteristics diagram, showing the distance as more than 850 mm. Comparison was made between the estimated fragment mass values of the models and the measured values, with the latter larger than the former. It was concluded that the state of the chemical reaction on the cast HMX/TNT/AL compositions was not detonation but deflagration. According to the Adams & Pack model and the CJ deflagration model, the distance of the shock formation and the pressure of combustion wave was semi-quantitatively evaluated. The results of the CJ deflagration model was found to be closer to the measured values than the Adams & Pack model.