激光辐照下黑索今固相与气相反应模型对比

摘要

In order to investigate laser⁃induced ignition and combustion mechanism of energetic material, solid⁃phase and gas⁃phase reaction models for RDX were proposed. Taking into account the detailed chemical reaction of gaseous products, control equa⁃tions were solved by finite different method and the ignition process was simulated with gas⁃phase reaction models. Only considering heat transfer and reaction in solid RDX, control equations were solved by finite element method and temperature and ignition time were obtained with solid⁃phase reaction models. Finally the predictions were compared with experiment data. It was found that igni⁃tion times predicted by these two models are all in good agreement with experiment. Though the detailed ignition process can be sim⁃ulated by gas⁃phase reaction models, the calculation process is very complex. On the other hand, though the decomposing and chemical reaction of gaseous products can not be described by solid⁃phase reaction models, the calculation process is very simple and the precision of ignition time can meet the needs of engineering design.%为了研究激光辐照下含能材料的点火和燃烧机理，建立了典型含能材料黑索今（ RDX）的固相与气相反应模型。气相模型考虑了多组分气体化学反应，采用有限差分方法求解控制方程，模拟了黑索今激光点火全过程。固相模型只考虑固相区域的传热和化学反应，采用有限元方法求解控制方程，获得了黑索今温度变化和点火时刻。最后，将2种模型计算结果与试验数据进行了比较。结果表明，2种模型的激光点火时刻，计算值均与试验值吻合；气相模型更能全面描述含能材料的点火过程，但计算过程相对复杂；固相模型不能描述点火过程中气相产物分解和反应过程，但计算过程相对简单，能模拟的入射热流范围更大，预测的点火时刻精度也满足工程需要。