2,4-二硝基苯甲醚基熔铸炸药慢速烤燃过程传热特征分析

Analysis of the Heat Transfer Characteristics of DNAN-based Melt-cast Explosive in Slow Cook-off Test

为探究2,4-二硝基苯甲醚基熔铸炸药慢速烤燃过程的内部传热特征,设计了3组试验装置并进行烤燃试验。通过试验获得了炸药内部各测点在1 K/min热刺激下的温度变化曲线,其相变温度为73℃,响应温度为205℃,响应后均表现为不完全燃烧反应;结合响应结果判断出点火点位于弹体上部;系统地描述了炸药从固相到液相再到响应的内部温度变化过程。通过数值模拟观察了炸药相变的整个过程,对炸药受热时内部温度场变化进一步分析后发现:固相时炸药内部温度场为同心类椭圆状分布,液相时内部温度场为类层状分布;炸药相变后内部存在自然对流,对流是影响炸药点火点位置分布的主要因素。

3 experimental devices were designed to investigate the internal heat transfer characteristics of2,4-dinitroanisole( DNAN)-based melt-cast explosive in slow cook-off test,and tested by scaled thermal explosion experiment. The temperature curves of internal monitoring points in the explosive under a thermal stimulus with the rate of 1 K/min were obtained. It is found that the phase-transition temperature is73 ℃,the ignition temperature is 205 ℃,and the incomplete combustion reaction occurs after ignition.The ignition location is estimated to be on the upper half of bomb body. The changing process of internal temperature of DNAN-based melt-cast explosive is described. The internal temperature field was analyzed by numerical simulation,and the whole process of phase transition was observed. The results show that the internal temperature field of explosive in solid phase is elliptical,and its internal temperature field in liquid phase is layered. A natural convection arises inside the explosive after phase transition,which is a major factor to affect the ignition location distribution of the explosive.