Steady State Burning Mechanism of Composite Solid Propellants Including Those with Negative Pressure Exponents

摘要

In order to study the steady state burning mechanism of AP-based composite solid propellants including those with negative pressure exponents, we applied the scanning electron microscope to examine samples of extinguished combustion strands and we also applied the single-frame microphotography of self-illumination or laser-shadow to observe the burning samples. We found that the covering of the melten binder over the AP surface was not a particular phenomenon of the PU propellant in the 'mesa' burning area, but rather a general phenomenon taken place over an extensive region. We showed indication that local covering may not have resulted in local extinction and we further proposed a new theoretical model which takes into consideration the combined effect of the covering of the melten binder on the AP surface and the existence of condensed phase reaction as well as the reversed gasification under the surface covering. This model can be used for AP-based solid composite propellants which include the easily melten binder. This model exhibits the capability of explaining the 'plateau', 'mesa', and normal burning behavior and it can also be used to analyze the effects of initial temperature and the AP particle size on the burning characteristics. Keywords: Solid rocket propellants, Erosive combustion, Non-steady state combustion, Translations, China, Chinese language. (AW)