含硼富燃料推进剂燃烧表面"沉积层"研究

针对含硼富燃料推进剂低压燃烧时燃烧表面产生“沉积层”的现象,结合该推进剂的燃烧过程,分析了“沉积层”的形成机理,建立了“沉积层”影响燃气流动的数学模型,研究了其对气相火焰高度的影响。结果表明,“沉积层”使气相火焰高度降低,传给燃面的热流密度占气相总热流密度的百分比增大,有更多的气相燃烧产生的热量反馈回燃烧表面,即使含硼富燃料推进剂燃烧过程中气相作用增强,易于在低压下维持稳定燃烧,并具有相对高的燃速和压强指数。这为含硼富燃料推进剂用于冲压发动机提供了有利的理论支持。

Study on burning surface sedimentary deposit of boron-based fuel-rich propellant

Aiming at the sedimentary deposit generated on the burning surface of boron-based fuel-rich propellant under low-pressure,formation mechanism of the sedimentary deposit was analyzed in combinition of combustion process.The mathematicalmodel used for describing the effect of sedimentary deposit on gas flowwas derived,and the effect of sedimentary deposit on gaseousflame height was investigated.The results show that existence of sedimentary deposit can make gaseous flame height decrease andthe percentage of heat flux density fed back to burning surface to total gaseous heat flux density increase,and more heat quantitygenerated by gas-phase combustion can be fed back to burning surface.In other words,existence of sedimentary deposit enhancesgaseous combustion effect during the combustion of boron-based fuel-rich propellant,so the propellant can keep steady combustioneasily with high burning rate and pressure index under low-pressure.This conclusion provides the favorable theory basis for the ap-plication of the boron-based fuel-rich propellant to ducked engine.