单质炸药爆轰反应区的力-化学耦合递阶多尺度模型研究

The intrinsic physical and chemical properties of explosives decide their detonation reaction zone structures and the temporal and spatial distributions of the physical quantities (such as composition, energy, pressure，acoustic velocity, particle velocity, and so on) in the zone, and therefore deciding their detonation performances. It is a key to speeding up the design and preparation of new explosives to predict their detonation reaction zone structures and the evolvement rules of the relevant physical quantities in the zone starting with the microscale simulations of their physical and chemical properties. This research project aims at building a hierachical multiscale model of "mechanical-chemical coupling" thorough investigating the coupling between the non-ideal detonation wave propagation and the mechanisms of energy feedback and energy release in the detonation reaction and investigating the hierachical multiscale parameter passing from the microscale simulation of explosives to the macroscale coupling model, in order to model the detonation reaction zone structure, study the rules of the temporal and spatial distributions of the physical quantities in the zone, and predict detonation parameters, and hence finding out a practical avenue of predicting the macorscale detonation performances of explosives based on their microscale simulations and also providing an effective prediction tool for designing and preparing the low-sensitive or insensitive explosives.

炸药内在物理化学性质决定了爆轰反应区的结构及物理量（如组成、能量、温度、压力、声速、粒子速度等）在反应区内的时空分布规律，因而也决定了炸药的爆轰性能。从炸药物化性质的微观尺度模拟出发，预测炸药爆轰反应区结构及相关物理量在反应区内的演化规律是加速新型炸药设计和研制进程的关键所在。本项目拟通过研究非理想爆轰波传播与爆轰反应中能量反馈、释放机制的耦合，以及研究从炸药微观模拟至宏观耦合模型的递阶多尺度参数传递，构建出"力-化学耦合"递阶多尺模型，以实现炸药爆轰反应区结构模拟、反应区物理量时空分布规律研究和爆轰参数预测,从而为基于炸药微观模拟预测宏观爆轰性能找到一条可行的途径，也为我国低、钝感炸药设计和研制提供行之有效的预测工具。

建立不依赖于参数调节的爆轰动力学一直是我国含能材料界长期存在的“瓶颈”。本项目的主要4个研究内容为：(1) RDX炸药能量反馈递阶多尺度模型研究；(2) 能量释放递阶多尺度模型研究；(2) “力-化学耦合” 递阶多尺度爆轰理论模型及其程序研制；(3) RDX炸药爆轰反应区碳团簇演化动力学研究及其程序研制；(4) RDX炸药爆轰反应区结构模拟研究。通过上述研究，获得如下主要研究进展和重要结果：发展出炸药全原子自洽力场(SCFF)技术和自洽力场－声子(SCFF-phonon)非谐自由能计算方法，并构建出固体炸药SCFF-phonon微观完全状态方程、“声子热点耦合”能量释放方程、与碳团簇相耦合的气体产物通用维利状态状态方程以及爆轰碳团簇演化动力学方程等，进而构建 出“力-化学耦合”递阶多尺度爆轰理论模型，实现了不依赖于参数调节的多尺度爆轰动力学模拟。研究成果为追赶国际爆轰动力学和爆轰物理前沿以及为下一步发展出可与美国cheetah程序相比拟的爆轰动力学预测程序提供坚实的理论基础和技术途径。