On the Stability of the Self-Sustained Combustion of Energetic Materials with Intense Subsurface Heat Release

In modeling the combustion of quasi-homogeneous energetic materials (EMs), much effort is spent on a more accurate description of the processes in the gas phase, an approach implying that the gas phases determine the whole picture of the combustion process. At the same time, the ever growing body of evidence suggests that the processes in the condensed phase play a leading role in the combustion of a number of common EMs at pressures of 40 to 100 atm. In this case, the subsurface reaction zone is unstable. The concepts of this previously unknown type of instability make it possible to plausibly explain the effect of transversal combustion waves, which were experimentally observed for EMs with gaseous product release, including combustion in the Zel’dovich-Novozhilov stability region. Arguments in favor of such waves being of phase character are presented. These conclusions are valid for the Zel’dovich-Novozhilov instability as well. A problem of modeling the combustion of EMs with instability in the subsurface reaction zone was formulated.