Initiation of Detonation by the Interaction of Shocks with Density Discontinuities

Abstract

The basic processes in the shock initiation of inhomogeneous explosives have been investigated theoretically using the model of a cylinder of nitromethane containing a void or an aluminum pellet. The interaction of a shock with the density discontinuities, the resulting formation of a hot spot, and the buildup to propagating detonation were computed using two-dimensional numerical hydrodynamics of the ``PIC'' type with chemical reaction and accurate equations of state. The hot spots formed at aluminum pellets exhibit failure or propagation of detonation in approximately the same manner as the one-dimensional, hydrodynamic hot spots studied previously. The failure of hot spots formed at voids could be studied only in those cases in which the failure mechanism did not depend on details of the structure of the reaction zone, as this structure could not be reproduced in the calculation.