The structure of low-velocity detonation waves

Abstract

In an attempt to clearly define the structure of low-velocity reaction waves, a number of liquid explosives known to undergo low-velocity detonation were examined using both high-speed photography and flash radiography. Owing to experimental limitations, low-velocity detonations could not be induced in all of the systems investigated. However, near sonic and supersonic reactions were observed in all the explosives investigated. When the reactions were clearly supersonic, the leading edge of the reaction zone consisted of a gradually curved shock front, concave in the direction of propagation, followed by an apparently unperturbed region. Behind this region, pockets of lower X-ray absorbency developed throughout the body of the fluid; undoubtedly, these pockets were reacting cavities in late stages of growth. Thus, these observations offer support for a previously postulated model for low-velocity detonation. The radiographic observations also indicate that fluid cavitation may play an essential role in the propagation of subsonic reactions.