EVOLUTION OF A REACTION CENTER IN AN EXPLOSIVE MATERIAL.

Experimental observations of ignition in explosive systems demonstrate that as a rule, combustion first sets in at small, discrete sites where inherent inhomogeneities cause chemical activity to proceed preferentially and lead to localized explosions. Combustion waves propagating away from these 'reaction centers' eventually envelope the remaining bulk. This study examines the spatial structure and temporal evolution of a reaction center for a model involving Arrhenius kinetics. The center, characterized by peaks in pressure and temperature with little diminution in local density, is shown to have one of two possible self-similar structures. The analysis employs a combination of asymptotics and numerics, and terminates when pressure and temperature in the reaction center have peaked.