基于阶梯多根装药的固体火箭发动机内弹道设计方法研究

Internal ballistics design method of solid rocket motor based on ladder⁃shaped multiple propellant

对于大长径比的固体火箭发动机,采用阶梯多根装药结构设计,可以增加推进剂的燃烧面积,提高发动机的做功效率。针对两段阶梯多根装药结构设计方案,总结出了固体火箭发动机内弹道设计方法;并以某工程项目为背景,完成了火箭发动机的结构设计及装药结构设计,给出了两段阶梯的装药结构、点火药装填方式以及燃烧室和喉部结构尺寸;进行了试验验证分析,表明固体火箭发动机的设计方案完全达到了设计指标要求。在膛压不大于16.8 MPa的情况下,实现了最大推力251.5 kN,持续推力168.7 kN,总冲量大于160 kN·s,工作时间小于900 ms,点火正常,膛内压力稳定。证明了内弹道设计方法的有效性,为阶梯多根装药火箭发动机的总体结构设计和装药结构设计以及开展性能研究工作提供了重要的试验依据。

For the solid rocket motors(SRMs)with a large aspect ratio,both the burning area of the propellant and the effi⁃ciency of the motor can be optimized by using the structure design of ladder⁃shaped multiple propellants.According to the structural design scheme of two⁃stage ladder⁃shaped multiple propellant,the internal ballistics design method of solid rocket motors were sum⁃marized.Based on a certain project,the structural design and charge design of SRMs were completed with the two⁃stage ladder⁃shaped propellant structure,ignition charge loading method,combustion chamber and throat size obtained.With the analysis of testing verification,the design scheme of SRMs completely reached the requirement of design index.When the chamber pressure is not more than 16.8 MPa,the maximum thrust is 251.5 kN,the sustained thrust is 168.7 kN,the total impulse is greater than 160 kN·s,the working time is less than 900 ms,the ignition is normal,and the pressure in the chamber is stable.The validity of the internal ballis⁃tics design method is proved,which provides an important experimental verification for overall structure design,charge structure de⁃sign and performance research of ladder⁃shaped multiple propellant rocket motors.