Nonlinear heterogeneous model of composite solid-propellant combustion

A computational model of composite solid-propellant combustion that combines three important properties is described. First, the model is heterogeneous, in that it incorporates a multilevel flame structure similar to the Beekstead-Derr-Price proposition. Second, it is nonsteady, and its main purpose is to predict pressure-coupled frequency response. Third, it is fully nonlinear, where thermal capacitance calculations come from a computational solution of the transient heat-conduction equation separately in the oxidizer and binder. Calculations show a frequency response that varies significantly with oxidizer particle diameter and mean pressure. Some observed trends are that the magnitude of the real part of R-P tends to diminish with higher mean pressures and that propellants with very coarse oxidizer particles tend to develop two peaks, one for the oxidizer and one for the binder.