Chapter 17 - Detonation Waves in Gaseous Explosives

Abstract

This chapter discusses detonation waves in gaseous explosives. A gaseous explosive mixture can sustain two modes of combustion distinguished by their propagation mechanism. A deflagration wave propagates via molecular (or turbulent) transport of heat and chemical species from the reaction zone to the unburned mixture ahead of it to effect ignition. A deflagration wave is essentially a diffusion front and propagates at low subsonic speeds with a pressure drop across the wave. A detonation wave is a compression shock wave and must necessarily propagate at supersonic speeds. Because of the extreme detonation pressures in condensed explosives, material strength becomes negligible and the detonation processes can also be described by the hydrodynamic equations as in gaseous detonations. Thus, the basic theory for condensed-phase detonations is essentially the same as that for gaseous detonations, differing only in the equation of state used to describe the products. Thus, hydrodynamic transport processes play a dominant role in the reaction zone of gaseous detonations.