一种改进的Euler方法模拟凝聚炸药的爆轰过程

【作者】 张波；

【导师】 张文宏；

【作者基本信息】 中国工程物理研究院 ， 流体力学， 2005， 硕士

【摘要】 在爆轰的数值模拟中,采用合适的计算方法及相应的计算程序,在计算机上数值求解流体力学和化学反应动力学方程组,以正确反映爆轰过程,对于爆轰理论以及工程应用研究,都是十分重要的。 本文使用一种改进的Euler方法,把无波动、不含自由参数的NND格式应用到凝聚炸药的爆轰问题,实现了高分辨格式对复杂物态方程爆轰问题的数值模拟计算。化学反应率使用Lee-Tarver的点火成长模型,未反应的固体炸药和化学反应气体产物都使用JWL(Jones-Wilkins-Lee)状态方程。首先研究了一维平面爆轰波结构与网格尺寸的关系,然后研究了柱面散心爆轰波结构及其正规反射、Mach反射问题。 文中数值模拟了非均质固体炸药PBX-9404的爆轰传播过程。从典型爆轰算例来看,该方法正确预测了凝聚炸药爆轰的起爆及传播过程中的关键特征,如Von Neumann尖峰和化学反应区等。通过数值模拟值与理论结果和试验结果的比较,各物理量均达到了满意的准确程度。更多还原

【Abstract】 Numerical simulation of detonation is to apply appropriate numerical methods to calculate the complicated detonation process of fluid dynamics coupled with chemical reaction. The study of numerical scheme is always concerned in the numerical simulation of detonation.In this paper, we applied NND scheme, a non-oscillatory, no free parameters and dissipative scheme, to numerical simulation of detonation in heterogeneous explosives with an improved Eulerian method. The ignition and growth model by Lee-Tarver is used to the chemistry reaction law of explosives, then a practical method for detonation simulation is constructed. First, The relation between one dimension plane detonation wave configuration and mesh size was investigated, then, regular reflection and Mach reflection was studied too.Simulations of detonation problem in heterogeneous explosives of PBX-9404 have been performed. From some representative examples about unsteady detonation, this method can correctly predict the key characters of initiation and propagation of detonation course, such as Von Neumann spike pressure and reaction zone width. Comparisons between the exact and numerical results, show that all parameters are approached very well.更多还原