一种基于Virial理论的爆轰产物状态方程

A Virial-based equation of state for detonation products

爆轰参数理论计算热化学代码的核心在于选择合适的状态方程用于描述物质的热力学状态。为扩大状态方程适用范围、减少状态方程的经验参数,基于维里(Virial)理论建立了能够准确计算到第i个Virial系数的VLI状态方程。采用VLI状态方程研究了第2~9维里系数随温度的变化规律,对比了不同阶数维里系数的相对大小及其对氮气热力学状态曲线的影响程度;计算了氮气的高压Hugoniot曲线和低压等温线,并与VLW和JCZ两种状态方程的计算值以及相应的试验数据进行对比,进一步计算了典型炸药的爆轰性能,验证了VLI状态方程的可行性和适用性。

When describing the thermodynamic state of materials with the help of thermochemical codes,it is essential to use a proper equation of state.JCZ and VLW are two typical equation of states but either of them has some disadvantages.JCZ equation of state is derived without the introduction of any empirical constants,but its mathematical form is complicated and hard to calculate.In contrast,the mathematical form of VLW is simple and not difficult to calculate,but it introduces some empirical constants thus limits its application range.Combining the advantages of both JCZ and VLW equation of states,this paper established a so-called VLI equation of state which can accurately calculate the ith Virial coefficient on the basis of Virial theory.With this VLI equation of state,the effect of temperature on the 2nd-9th Virial coefficients were investigated,and after the verification of the VLI coefficients is performed,the Hugoniot and isotherm of nitrogen were calculated.The VLI equation of state can accurately calculate the Hugoniot of nitrogen if the decomposition of nitrogen is considered.In contrast,the VLI equation of state can reproduce the isotherm of nitrogen no matter whether the decomposition of nitrogen is considered.The experimental data of Hugoniot and isotherm of nitrogen were used to validate the VLI equation of state.As a comparison,the Hugoniot and isotherm of nitrogen were also calculated by both the JCZ and VLW equation of states.The VLI equation of state were also validated by detonation velocities of several explosives and can be used to predict the detonation performance of explosives.