On the mechanism of detonation initiations

Abstract

Two essential issues in detonation initiations were discussed in this paper, that is, hotspots and reaction zone acceleration. By defining the reaction zone acceleration, the hotspot and the reaction zone acceleration are identified as the primary mechanisms underlying the deflagration to detonation transition. The dominant physical process for two mechanisms is the interaction between gasdynamic non-linearity and chemical reactions that are very sensitive to temperature gradient. In the process, spontaneous waves are generated in the reaction zone, propagate with the local sound speed, decelerate suddenly in the front of the reaction zone because of the sharp temperature gradient, and develop into a pressure pulse acting to elevate the gas temperature that will further induce more intensive chemical reactions. Such a positive feedback loop supports detonation initiation and propagation