Theoretical studies for calculating the detonation products and properties of explosives
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摘要: 为实现爆轰产物组成和爆轰参数的计算,采用拉格朗日乘数法和牛顿迭代的方法预测爆轰产物组成,利用BKW状态方程预测爆轰参数,在0~600 GPa和300~15 000 K压力温度范围内选取金刚石作为碳的生成相;对爆轰产物系统采用最小自由能原理,结合牛顿迭代法求解爆轰产物的化学平衡方程组;对BKW状态方程参数提出修订,取α=0.5,β=0.298,θ=6 620,κ=9.50;采用自编程序实现计算过程。使用此方法和Hugoniot关系计算密度为1.77 g/cm3的PETN爆轰CJ点爆轰参数验证计算精度,结果显示计算与实验结果的误差均小于1%。利用此方法结合Hugoniot关系预测出爆轰CJ点的产物密度为2.43 g/cm3。Abstract: In order to calculate the detonation products and parameters, Lagrange multiplier and Newton iterative method were used to predict detonation products. The state equation of BKW was used to predict detonation parameters. In a range of pressure from 0 to 600 GPa and temperature from 300 to 15 000 K, diamond was intended as the elemental carbon product. Based on the principle of minimum free energy, the equilibrium compositions of detonation products were calculated by using Newton iterative method, which need not calculate the free energy of each composition. The parameters of the state equation of BKW were modified.α=0.5; β=0.298; θ=6 620; κ=9.50. Using self-made program, the detonation properties at CJ point of PETN, whose density is 1.77 g/cm3, were calculated with the theory in this paper and the equation of Hugoniot. The results show satisfactory agreement with the experimental data, with the error less than 1%. The density of detonation products is also predicted easily. When the density of PETN is 1.77 g/cm3, the density of detonation products is 2.43 g/cm3.
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表 1 BKW状态方程参数取值
Table 1. The parameter values of BKW equition of state
炸药 α β θ κ RDX 0.5 0.16 400 10.91 工业炸药 0.5 0.16 2 890 10.91 本文中 0.5 0.298 6 620 9.50 表 2 每摩尔PETN炸药CJ点爆轰产物组成
Table 2. Compositions of detonation products per mole of PETN explosive at CJ point
方法 n(CO2)/mol n(CO)/mol n(N2)/mol n(O2)/mol n(H2)/mol BKW[1, 2] 3.950 9 0.096 2 1.999 2 1.359 1×10-5 0.568 9×10-4 LJD[1, 2] 3.779 0 0.446 9 1.969 5 0 0.480 4×10-1 WCA[13] 3.934 9 0.154 6 1.991 7 4.494 3×10-5 3.989 5×10-4 本文 3.999 5 0.001 1 1.999 9 1.190 4×10-5 2.077 7×10-4 方法 n(H2O)/mol n(NH3)/mol n(NO)/mol n(CH4)/mol n(C)/mol BKW[1, 2] 3.998 6 1.327 5×10-4 2.244 1×10-4 0.537 3×10-5 0.951 6 LJD[1, 2] 3.929 1 0 0.619 5×10-1 1.197 9×10-2 0.759 8 WCA[13] 3.975 2 1.629 0×10-2 3.141 7×10-4 0 0.910 5 本文 3.999 7 7.354 8×10-8 4.530 7×10-6 5.482 0×10-6 0.999 1 -
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