孔隙塌缩对工业炸药爆轰的多重作用  

The multiple effects of void collapse on detonation of commercial explosives

作　　者：李晓杰[1,2] 王小红[1,2] 王宇新[1,2] 闫鸿浩[1,2] LI Xiao-jie;WANG Xiao-hong;WANG Yu-xin;YAN Hong-hao(Department of Engineering Mechanics,Faculty of Vehicle Engineering and Mechanics,Dalian University of Technology,Dalian 116024,Liaoning,China;State Key Laboratory of Structural Analysis for Industrial Equipment,Dalian 116024,Liaoning,China)

机构地区：[1]大连理工大学运载工程与力学学部工程力学系,辽宁大连116024 [2]工业装备结构分析国家重点实验室,辽宁大连116024

出　　处：《工程爆破》2021年第4期1-13,21,共14页Engineering Blasting

基　　金：国家自然科学基金资助项目(12072067,11672067)。

摘　　要：通过对工业炸药爆轰反应过程中微孔隙压溃的细观与宏观过程进行研究,提出炸药孔隙压溃不仅产生绝热压缩、射流冲击、摩擦剪切生热的“热点”因素;冲击射流产生的旋涡运动,还会起到搅拌混合作用,促进爆轰燃烧反应;同时旋涡运动的湍流能量还会通过粘性耗散转变为热能,供给爆轰波,与化学反应放热一起维持爆轰传播;即工业炸药爆轰中的微孔隙塌缩同时起到了“热点”、搅拌混合促燃和湍流释能的多重作用。炸药孔隙的搅拌混合作用决定了“化学反应区”和“湍流耗散区”的厚度大小,其中“化学反应区”的厚度与孔隙度成反比,“湍流耗散区”则与孔隙度成正比,两者的共同作用构成支持爆轰波的“释能区”,这使得工业炸药存在能量利用率最高的最佳装药密度。基于爆轰波“释能区”的新观点,建立了工业炸药的最佳装药密度、极限直径、临界直径、高密度“压死”、炸药能量利用率等爆轰性能经典问题之间的内在联系。通过“孔隙混合效应”和乳化炸药粒径分析,基于敏化气泡与炸药粒径相匹配原则,提出对于粒径5~6μm的乳化炸药,敏化气泡以直径10~100μm为最佳。Based on the study of micro and macro effects of micro void collapse on detonation,it was put forward that void collapse in industrial explosives not only produces ignition"hot spot"factors such as adiabatic compression,jet impact,friction and shear deformation,but also plays important roles in mixing and promoting combustion of detonation chemical reaction when the impacting jet continues to develop into vortex,and furthermore in maintaining detonation wave propagation when the turbulent energy of vortex is transformed into heat energy through viscous dissipation.Therefore,the high-speed void collapse in the detonation of industrial explosives plays a triple role of"hot spot",combustion promoter by turbulent mixing and energy releaser by turbulent dissipation.The thickness of"chemical reaction zone"and"turbulent dissipation zone"is determined by the porosity of an explosive,the thickness of"turbulent dissipation zone"is directly proportional to the porosity,but the"chemical reaction zone"is the opposite.So the total contribution of both zones forms the thickness of the"energy release zone"supporting the detonation wave,and produces the optimum charge density with the highest energy utilization of detonation.According to this theory,the internal relationship among the optimum charge density,the limit diameter,the critical diameter,the"dead press"of high density,and the energy utilization rate of industrial explosives is established.By using the"void mixing effect"and the particle size analysis of emulsion explosives,and based on the principle that sensitizing bubbles match with the particle size of the explosive,the result is obtained that 10-100μm diameter bubble sensitization is the optimum for the emulsion explosive in medium particle size 5-6μm.

关 键 词：工业炸药 爆轰 孔隙塌缩 热点 湍流混合 湍流耗散 反应区 释能区 

分 类 号：O381[理学—流体力学] TQ560.1[理学—力学]