On the continued acceleration of bomb casing fragments following casing fracture  

作　　者：Michael D.HUTCHINSON David W.PRICE 

机构地区：[1]AWE.Aldermaston,Reading RG7 4PR [2]Institute of Shock Physics,Imperial College

出　　处：《Defence Technology（防务技术）》2014年第2期211-218,共8页Defence Technology

基　　金：sponsored by the NWIPT Department of the U.K.Ministry of Defence

摘　　要：It has been said that,once a bomb casing has fractured, "detonation gases will then stream around the fragments or bypass them,and the acceleration process stops there." However,while apparently copious gas flow through casing fractures indicates some pressure release,it is also an indication of significant gas drive pressure,post casing fracture.This paper shows two approaches to the problem of calculating the actual loss of drive.One presents first-order analytical calculations,in cylindrical geometry,of pressure loss to the inside surface of a fractured casing.The second shows the modelling of a selected example in the CTH code.Both approaches reveal that gas escape,while occurring at its own soundspeed relative to the adjacent casing fragments,has to compete with rapid radial expansion of the casing.Together with some historic experiments now publicly available,our calculations indicate that post-fracture casing fragment acceleration is,for most systems,unlikely to be reduced significantly.It has been said that, once a bomb casing has fractured, ＂detonation gases will then stream around the fragments or bypass them, and the acceleration process stops there.＂ However, while apparently copious gas flow through casing fractures indicates some pressure release, it is also an indication of significant gas drive pressure, post casing fracture. This paper shows two approaches to the problem of calculating the actual loss of drive. One presents first-order analytical calculations, in cylindrical geometry, of pressure loss to the inside surface of a fractured casing. The second shows the modelling of a selected example in the CTH code. Both approaches reveal that gas escape, while occurring at its own sound- speed relative to the adjacent casing fragments, has to compete with rapid radial expansion of the casing. Together with some historic ex- periments now publicly available, our calculations indicate that post-fracture casing fragment acceleration is, for most systems, unlikely to be reduced significantly.

关 键 词：壳体破裂 外壳 炸弹 气体逸出 压力损失 计算表 加速过程 压力释放 

分 类 号：TQ560.1[化学工程—炸药化工]