Model of non-stationary combustion of solid energetic materials with accumulation of condensed products on the burning surface

The unsteady combustion of solid propellants with the formation of condensed products accumulating on the burning surface in the form of a skeleton layer is considered. The model of the process takes into account the thermal inertia of the skeleton layer and the variation in its mass when burning. It is shown that during the unsteady combustion of such propellants, the instantaneous composition of both gaseous and condensed products leaving the burning surface changes and becomes different from that during the stationary combustion; thus, it differs from the initial composition of the propellant. This new effect, which was not previously described in the literature, can lead to additional destabilization of the process in a solid propellant rocket motor combustion chamber and to the development of acoustic instability. Within the framework of the presented model of unsteady combustion, the component of the acoustic conductivity of the solid propellant burning zone associated with the new effect is determined.