金属/炸药结构在组合激光辐照下装药点火的数值模拟

Numerical Simulation of Initiation of Metal / explosive Structure Irradiated By Combined Laser

基于组合激光的新概念,对重频脉冲激光与连续激光组合辐照下金属/炸药结构的温升、炸药的热点火规律进行了数值计算。根据一维热传导方程与炸药放热反应理论,考虑金属表面能量耦合系数及物性参数随温度的变化,计算了不同组合参数下金属/炸药结构的温升以及炸药的热点火时间,初步探讨了组合激光的优势。结果表明:在金属表面不发生相变的情形下,在连续激光中加入适当比例的重频脉冲激光,能够提高目标对激光能量的利用效率,增大目标的温升,加快炸药的点火。在平均功率密度相同时,辐照相同的金属/炸药结构使其点火,组合激光所需时间要比连续激光少,且随着金属层厚度的增大其优势更加明显。

Based on the new concept of combined laser,and using the one-dimensional heat-conduction equation and the exothermic reaction theory of explosive,the initiation of metal / explosive structure irradiated by combined laser are calculated,considering the temperature dependences of the energy coupling coefficient and the material properties of the metal. In the condition that the phase change of the metal doesn't occur,the initiation time decreases as the proportion of the pulse laser in the combined laser increases. In the same average laser intensity,the time needed to ignite the metal / explosive strcture irradiated by combined laser is less than that of the continuous laser,and the advantage is more obvious as the thickness of the metal casing increases.