炸药颗粒床冲击加热多尺度数值计算

摘要

对一维两相流模型进行简化,引入热点模型和阿伦尼乌斯反应速率方程,考虑炸药颗粒的可压缩性以及固液相变的影响,建立了炸药颗粒床冲击加热的多尺度计算模型,对活塞冲击颗粒药床进行数值模拟.研究了致密波区内的固相体积分数、压力、密度、整体平均温度和颗粒尺度的温度分布.结果表明:对于亚音速致密波,固相体积分数、压力、密度和整体平均温度光滑地从初始值过渡到平衡状态；相同的加载条件下,颗粒尺度的热点温度明显高于整体平均温度,并超过了熔点,可以观察到相变的发生.在颗粒接触面附近,化学反应发生,温度出现突跳.并研究了活塞速度、初始体积分数和颗粒半径等模型参数对颗粒药床压缩性能的影响.%A multiscale model and Arrhenius reaction rate equation are used to analyze the compaction processes in granular high-explosive HMX. Analysis of the steady-state wave structure indicates that for subsonic compaction wave, the model variables, such as solid volume fraction, pressure, density, transit from the initial value to the equilibrium state smoothly. The evolution of the grain temperature shows that the peak hot spot temperature near the intergranular contact surface, which exceeds the melting temperature , would trigger chemical reaction although the bulk average temperature is very low. In case of chemical reaction, the piston speed needed to stimulate chemical reaction for the same initial conditions is higher due to solid-liquid phase change which consumes part of the bulk compaction work. At last, numerical experiments were performed to determine the model sensitivity to variations in key energy localization parameters.