呈正、负压强指数的复合固体推进剂稳态燃烧模型

A STABLE COMBUSTION MODEL FOR COMPOSITE SOLID PROPELLANT WITH POSITIVE OR NEGATIVE BURNING-RATE PRESSURE EXPONENT

关键词:  固体推进剂  燃烧性能  X射线光谱学

Key words:  Solid propellant  Combustion performance  X-ray spectroscopy

摘要:

通过X光电子能谱和扫描电镜对推进剂和过氯酸铵-粘合剂的多层夹心件之熄火样品的观察,研究了在复合推进剂的燃烧中,压强和添加剂CaCO₃对过氯酸铵被熔化粘合剂覆盖的面积分数（γ）和过氯酸铵的凝相反应分数（G）的影响。在作者已提出的“两区模型”的基础上,发展了一个新的“统一模型”（UM）。该“统一模型”是一个进一步考虑了熔化粘合剂的覆盖,在覆盖下存在反向气化和受燃速调节剂（例如CaCO₃）控制的凝相反应的理论模型。为了计及过氯酸铵颗粒尺寸的分布,像PEM模型一样,统计的方法也被引入了本模型。本模型不仅能用来分析初温、过氯酸铵颗粒尺寸及其分布对燃烧特性的影响,而且可以用来解释平台、麦撤和常规的燃烧特性。同时,本模型还能够成为研究包括负压力指数在内之固体复合推进剂的侵蚀燃烧与燃烧不稳定性研究的基础。

Abstract:

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.