Some statistical considerations in the burning of composite solid propellants

Propagation of a deflagration wave through a nearly ordered composite propellant is considered. The intent is to see some effects of the particle packing statistics on the propagation rate. A highly oversimplified model of the deflagration physics is considered, and only the statistics are emphasized. It is found that, for propellants of usual packing density, the least-time path of burning to a given point depends primarily on the packing statistics in a line parallel to the burn rate vector; there is little effect of particles only a few particle diameters to the side of this line. In a simplified model that may be solved analytically, there are clearly seen particle-size, pressure, and packing density effects on burn rate which are due to the statistics alone and not the deflagration physics.