Transition from Deflagration to Detonation in Cast Explosives

Abstract

An experiment is described in which velocity and pressure changes during the transition from slow burning to detonation in cast explosives are measured. A simple one-dimensional physical model of explosive burning under confinement is assumed and used, in connection with experimental evidence, as the basis for a calculation of the time and distance necessary to start a shock in a deflagrating solid explosive. The calculated distance of incipient shock formation is 11–15 cm. This result supports the hypothesis that transition from slow burning to detonation is due to a shock which arises spontaneously in a confined burning medium. The nature of the shock-forming pressure pulse, p=p(t), is discussed.