接触爆炸和近距离爆炸比冲量数值仿真研究

对于接触爆炸和近距离爆炸的情况，炸药形状、起爆点位置和产物喷射均会造成载荷空间分布复杂，给理论分析和工程应用带来困难。分别采用流固耦合方法和PBM方法对Nansteel近距离爆炸子弹抛掷实验进行数值仿真，结果表明PBM模型仿真结果和实验结果吻合较好，而流固耦合模型仿真结果仅为实验值的70%左右.对于高度为3～10 cm的等长径比TNT药柱接触爆炸仿真结果表明，中心点比冲量随药柱高度线性变化.对640 g和1 250 g等长径比TNT药柱仿真结果表明，爆心距的变化主要影响靶板中心点6 cm半径内的比冲量，基于量纲分析推导出了比冲量的经验公式. 

Investigation of Specific Impulse Under Contact Explosion and Close-in Explosion Conditions Using Numerical Method

For contact explosion and close-in explosion, blast load distribution will be effected by the shape of explosive, the location of detonation point and product injection, which poses difficulties to theoretical analysis and engineering application. In order to study the specific impulse generated by contact explosion and close-in explosion, numerical simulations were made using the fluid-solid coupling method and PBM method according to a close-range explosive experiment done by Nansteel. The results showed that the simulation of the PBM model agreed well with the experimental results, while the fluid-solid coupling simulation results were only about 70% of the experimental values. The simulation results of contact explosion of isometric diameter ratio TNT column showed that the center point ’s specific impulse changed linearly with the diameter. The change of the core distance mainly affected the specific impulse within the 6 cm radius of the target center point when 640 g and 1 250 g TNT columns were used. Based on dimensional analysis, the empirical formula of specific impulse was obtained.