Physical mechanisms of high-enthalpy initiation

Injection of a hot gas flow produced by an external source into a powdered explosive allows very fast (within a few microseconds) deflagration-to-detonation transition. Under this high-enthalpy initiation conditions, the process begins with the stage of convective combustion, and the initial velocity of the wave is about 1 km/s. The combustion kinetics known from the literature does not provide the observed rapid development of the process. Various mechanisms of acceleration of the reaction are considered. Results of calculation for a two-phase gas-dynamic model are compared with data of synchrotron diagnostics (set of density profiles in the wave).