NCJ Number
193188
Journal
Shock Waves (2001) Volume: 10 Dated: 2001 Pages: 431-443
Date Published
2001
Length
16 pages
Annotation
This paper describes experimental and numerical investigation on the mechanism by which solid particles penetrate the shock front during the explosive dispersion process.
Abstract
The study investigates experimentally and numerically the rapid dispersal of inert solid particles due to the detonation of a heterogeneous explosive, consisting of a packed bed of steel beads saturated with a liquid explosive. Detonation of the spherical charge generates a blast wave followed by a complex supersonic gas-solid flow in which, in some cases, the beads catch up to and penetrate the leading shock front. The study also investigates experimentally, with flash X-ray radiography and blast wave instrumentation, the interplay between the particle dynamics and the blast wave propagation as a function of the particle size and charge diameter. The flow topology during the dispersal process ranges from a dense granular flow to a dilute gas-solid flow. The study discusses difficulties in the modeling of the high-speed gas-solid flow and develops a heuristic model for the equation of state for the solid flow. This investigation indicates that the crossing of the particles through the shock front strongly depends on the charge geometry, the charge size, and the material density of the particles. Moreover, there is a particle size limit below which the particles cannot penetrate the shock for the range of charge sizes considered. Above this limit, the distance required for the particles to overtake the shock is not very sensitive to the particle size but remains sensitive to the particle material density. The paper concludes that, overall, there is excellent agreement between the experimental and computational results. Figures, references