混合物冲击压缩后平衡态的研究

将混合物组元颗粒在三维网格内按组元比例随机分布，采用热动力学有限元数值方法，对其冲击压缩过程进行数值模拟。研究了混合物在冲击压缩下趋于热动力平衡过程、热平衡特征时间、压力平衡特征时间和平衡后的热力学状态，得出热平衡特征时间与颗粒度的平方近似成正比，而力平衡特征时间与颗粒度近似成正比。数值模拟了多种合金的冲击压缩特性，其结果与混合物物态方程的体积相加模型、一次冲击绝热线的叠加原理和实验等不同方法获得的结果作了比较，除冲击温度外，各方法得到的结果一致；体积相加模型和叠加原理不能给出合理的混合物冲击温度，但数值模拟能给出合理的混合物冲击温度。

Studies on the Equilibrium State of Mixture Following Shock Compression

The mixture is as a randomly distributed component grains in three-dimensional meshes.The shock compression behavior of mixtures is simulated numerically by using the 3D thermodynamics finite element method.We have studied the course of tendency to the thermodynamic equilibrium,the characteristic time of temperature equilibrium,the characteristic time of pressure equilibrium and the equilibrium state of mixture following the shock compression and found the relation between the characteristic time of temperature equilibrium and the square of the grain dimension of mixture and the linear relation between the characteristic time of pressure equilibrium and the grain dimension.The shock compression behaviors of some alloys are simulated numerically,and the results are compared with the fraction volume model of EOS,the superposition principle of the first shock Hugoniot,and the experimental results.Except for the shock temperature,the results are in good agreement with each other.The fraction volume model and the superposition principle cannot yield reasonable shock temperatures,but the numerical simulation method does.