Lagrangian Analysis For Shock Initiation Of Low-sensitive Explosives

Detonation growth of explosives under shock wave is a hot issue at present.The study of shock initiation process is helpful to understand the safety and power performance of explosives.In order to master the energy and sensibility of PBX,the reaction rate model needs to be studied.At present,the shock initiation process of high-energy PBX explosives is mainly described by empirical formula and meso-scale model of reaction rate.Based on the experimental results,the purpose is to obtain the reaction curve of PBX explosive by lagrangian analysis and program,to explore the characteristic of PBX explosive initiation,and to provide the basic data for calibrating the reaction rate equation.The main work and conclusions are as follows:(1)The lagrangian analysis was studied,and the result of CIM model was used as the input to verify the accuracy of the lagrangian program for calculating the reaction flow field of explosive.The result shows that the reliability of the program is good.Lagrangian analysis can accurately reflect the flow field in the absence of any state assumption.(2)Based on the lagrangian analysis,the reaction flow of PBXC03 and PBXC10 were calculated,and the reaction curves under different conditions were calculated using MATLAB program.The macro-kinetic reaction rates of both PBXC03 and PBXC10 explosives' detonation reduce with the decrease of loading pressure,and the sensitivity of explosives decrease with the increase of particle size.Under the same loading conditions,the reaction rate of PBXC10 explosives is lower than that of PBXC03.Only changing the particle size of HMX in PBXC10 explosive has little effect on the reaction rate.(3)By analyzing the reaction flow field and reaction curve of PBXC03 and PBXC10 explosives' shock initiation,it can be found that the shock initiation process of these two is significantly different.According to the calculated results,the main factor influencing the macroscopic chemical reaction kinetics of HMX-based PBX is the number of hot spots.However,the main factor that influence the kinetics of TATB-based PBX is the propagation velocity of combustion wave.This conclusion is consistent with the physical mechanism of HMX-based and TATB-based PBX explosives' initiation analyzed by Grebenkin based on the hot-spot theory.