A STABLE COMBUSTION MODEL FOR COMPOSITE SOLID PROPELLANT WITH POSITIVE OR NEGATIVE BURNING-RATE PRESSURE EXPONENT
Xu Wengan Wu Xinpiny Li Baoxuan Xie Weimin Yin Jinqi Wang Kexu Chen Buxuc Li Junli (Northwestern Polytechnic University) (The 806th Research Institute)
The effect of pressure and CaCO3 on the area fraction ofoxidizer covered with the molten binder (γ) and the mass fraction of reaction in the AP condensed-phase reactions (G) during composite solid pro-pellant combustion is investigated by means of X-ray photoelectron spectro-scopy (XPS) and SEM to exam the extinguished samples of propellants or AP-Binder-AP-Binder-AP sandwiches. On the basis of the two region model proposed by authors, a new unified model (UM) was developed.The UM is a analytical model in which the covering of the molten binder, opposed gasification, and the condensed phase reaction controlled by burning rate adjuster (for example CaCO3) under covered condition are further taken into account. In order to consider the size distribution of AP particle, the some statistical formulation is adopted in the present model as in the PEM.The present can be used for analysing the effect of initial temperature, AP particle size and its distribution on burning behaviors, and for explaining plateau, mesa and normal burning features. Moreover, the present model lays a fundation for studying the erosive burning and combustion instability of composite solid propellants, including those with negative burning rate pressure-exponent.