不同升温速率下炸药烤燃模拟计算分析

为了研究不同升温速率条件下炸药热反应规律,建立了炸药烤燃模型,利用计算流体力学软件,对固黑铝炸药(GHL)在不同升温速率下的烤燃过程进行了数值模拟计算.采用Arrhenius定律描述炸药自热反应,根据在1 K·min-1升温速率下固黑铝炸药烤燃实验测量的温度-时间曲线,确定了固黑铝炸药的活化能和指前因子分别为180.2 kJ·mol-1和2.1674 s-1; 分别对3.3 K·h-1,1 K·min-1,3 K·min-1和10 K·min-1四种不同升温速率下固黑铝炸药烤燃过程进行了数值模拟计算分析.结果表明,升温速率对炸药点火时间和点火位置有很大影响.升温速率增大,炸药点火时间缩短,点火位置从炸药内部移向炸药边缘.升温速率对炸药点火温度影响很小,但慢速烤燃下炸药点火时的环境温度比快速烤燃低.

Numerical Simulation of Cook-off for Explosive at Different Heating Rates

A cook-off model of explosive was established to investigate the characteristics of explosive thermal reaction at different heating rates. The numerical simulation was employed to model the cook-off process for GHL explosive at different heating rates by computational fluid dynamics(CFD) software. The decomposition reaction of explosive was described by Arrhenius-equation. According to T-t curves of cook-off test at heating rate of 1 K·min^-1,the activation energy and frequency factor were confirmed. The calculations were conducted to simulate the cook-off tests for GHL explosive at heating rates of 3.3 K·h^-1,1 K·min^-1,3 K·min^-1 and 10 K·min^-1,respectively. The results show that the external heating rate has much influence on the ignition time and ignition location. The ignition time of explosive decreases and ignition location removes from the interior to the edge of explosive cylinder with increasing of the heating rate. The ignition temperature is slightly affected by the heating rate. The environment temperature at igniting in slow cook-off test is lower than that in fast cook-off test.