负压力指数固体推进剂压力响应特性研究

Pressure Response Characteristics of Negative Pressure Exponential Solid Propellant

多喷管高频工作的固体姿轨控发动机,随着喷管等效喉部面积变化,燃烧室的压强会出现波动,波动的数值与推进剂的降压/升压特性、瞬变燃烧响应特性以及推进剂压力指数相关;而使用负压力指数推进剂减小了喷管等效喉部面积变化时燃烧室的压强波动,降低了阀门切换过程中压强的爬升时间。本文针对两个配方的负压力指数推进剂,开展三姿控多工况高频切换实验,通过旋转阀方法研究阀门在三种高频切换下的动态响应特性和燃烧室压强状态,可知,两个配方的负压力指数推进剂在同一工况高频切换过程中的降压速率均大于升压速率,升压过程的特征时间均大于降压过程的特征时间;负压力指数小的推进剂的降压和升压过程的特征时间更小。

The pressure in the combustion chamber of a solid attitude and orbit control motor with multiple nozzles operating at high frequency fluctuates with the change of the equivalent throat area of the nozzle,the fluc tuation values are related to the propellant depressurization/pressurization characteristics,the transient combustion response characteristics and the propellant pressure index,while the negative pressure index propellant reduces the pressure fluctuation of the combustion chamber when the equivalent throat area of the nozzle changes,reduces the pressure climb time during valve switching.In this paper,three attitude control and multiple working condi tions of high-frequency switching experiments are carried out for two kinds of negative pressure index propellants,and the dynamic response characteristics and combustion chamber pressure state of the valve under three kinds of high-frequency switching are studied by rotating valve method,the depressurization rate and the characteristic time of the boost process are both larger than those of the boost process in the same operating condition.The charac teristic time of depressurization and pressurization is shorter for propellants with small negative pressure index.