DNAN基熔铸混合炸药慢烤燃的尺寸效应

Study on the Size Effect of Cook-off of DNAN Based Melting and Casting Mixed Explosive

利用自行设计的烤燃试验装置,采用多点测温方式,以1.0℃/min的升温速率对3种不同装药尺寸的DANA基熔铸混合炸药进行慢烤,测量烤燃弹的温度变化,以此为基础,建立烤燃弹的计算模型,利用FLIENT软件对不同装药尺寸的烤燃弹进行了数值模拟,研究装药尺寸对DNAN熔铸混合炸药烤燃响应特性的影响。结果表明,约束条件和升温速率不变时,装药尺寸对DNAN基熔铸混合炸药的响应温度有明显影响,装药直径为19mm的烤燃弹在升温速率1.0℃/min下,当长径比小于4时,炸药的响应温度随长径比增大呈指数降低趋势,同时响应时间随装药尺寸增大也呈指数衰减;当长径比大于4时,炸药的响应温度趋于恒定,响应时间也基本不变。在升温速率不变时,DNAN熔铸炸药的相变温度与尺寸无关,在1.0℃/min升温速率下的炸药点火位置均在药柱中心,点火区域与装药尺寸呈几何相似。

The slow cook of three kinds of DANA based melting and casting mixed explosives with different charge sizes was carried out by the self-designed cook off test device at a heating rate of 1.0℃/rain and using multi point temperature measuring method. On the basis of this, the calculation model of cook of bomb was established. The numerical simulation of the cook off bomb with different charge size was carried out by using FLIENT software. The effect of charge size on the cook off response characteristics of DNAN based melting and casting explosive was studied. The results show that the charge size has a significant effect on the response temperature of DNAN based meltinf and casting mixed explosives when the constraining conditions and the heating rate do not change. For a cook off bomb with a diameter of 19 mm, at a heating rate of 1.0℃/min, when the length to diameter ratio is less than 4, the response temperature of the explosive decreases exponentially with increasing the ratio of length to diam eter and the response time decreases exponentially with increasing the size of the charge. When the length to diame ter ratio is greater than 4, the response temperature of the explosive tends to be constant, and the response time is basically unchanged. When the heating rate is constant, the phase transition temperature of DNAN based melting and casting explosives is independent of the size. At a heating rate of 1.0℃/rain, the ignition location of the explo sives is all in the center of the grain, and the ignition area is geometrically similar to the charge size.