Abstract
Experiments were conducted to investigate the initiation of an emulsion explosive containing cavities. Cylindrical cavities were created in thin sheets of either gelatine or an ammonium nitrate/sodium nitrate emulsion confined between transparent blocks. Shocks were launched into the sheets with either a flier-plate or an explosive plane-wave generator so as to collapse the cavities asymmetrically. The closure of the cavities and subsequent reaction in the explosive was photographed by using high- speed framing cameras. The collapse of the cavity proceeded in several stages. First, a high-speed jet was formed which crossed the cavity and hit the downstream wall sending out a shock wave into the surrounding material. Secondly, gas within the cavity was heated by rapid compression achieving temperatures sufficient to lead to gas luminescence. Finally, the jet penetrated the downstream wall to form a pair of vortices which travelled downstream with the flow. When such a cavity collapsed in an explosive, a reaction was observed to start in the vapour contained within the cavity and in the material around the heated gas. The ignition of material at the point at which the jet hit was found to be the principal ignition mechanism.
Reference55 articles.
1. A discussion on deformation of solids by the impact of liquids, and its relation to rain damage in aircraft and missiles, to blade erosion in steam turbines, and to cavitation erosion - The collapse of cavitation bubbles and the pressures thereby produced against solid boundaries
2. Besant W. H. 1859 Hydrostatics and hydrodynamics. Cambridge University Press.
3. Bourne N. K. 1989 Shock interactions with cavities. Ph.D. thesis University of Cambridge.
4. Bourne N. K. & Field J. E. 1989 Cavity collapse in a heterogeneous commercial explosive. In Proc. Ninth Symposium ( International)on Detonation Portland Oregon pp. 869-878.
5. Collapsing cavities in reactive and non-reactive media. In Proc. of the 19th;Bourne N. K.;Int. Conf. on High-speed Photography and Photonics, Cambridge,1990
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