液体火箭POGO振动分析的矢量拟合法  

Vector fitting method for liquid rocket’s POGO vibration analysis

作　　者：刘涛 刘锦凡 唐国安 LIU Tao;LIU Jinfan;TANG Guo’an(Department of Aeronautics and Astronautics,Fudan University,Shanghai 200433,China;Aerospace System Engineering Shanghai,Shanghai 201109,China)

机构地区：[1]复旦大学航空航天系,上海200433 [2]上海宇航系统工程研究所,上海201109

出　　处：《振动与冲击》2019年第19期26-30,51,共6页Journal of Vibration and Shock

基　　金：国家自然科学基金(11202052)

摘　　要：针对液体火箭的POGO振动现有分析方法存在不足的问题。建立了火箭推进-结构系统的传递函数,采用矢量拟合法对传递函数进行有理分式拟合,借助稳态图法确定传递函数稳定的极点,进而通过极点分布判断POGO稳定性;进一步分析了蓄压器不同设计状态对POGO振动的抑制效果并与临界阻尼法进行了对比。结果表明矢量拟合法比临界阻尼法具有更高的精度,并确定蓄压器PV值在0.157~0.196 MPaL范围内抑制效果最好;该方法可为其它液体火箭的POGO振动抑制提供参考。Aiming at shortcomings of existing analysis methods for liquid rocket’s POGO vibration,the transfer function for a rocket propulsion-structure system was established,and the vector fitting method was applied to fitthe transfer function with rational fraction.Then the transfer function’s stable poles were determined with the steady state diagram,and the pole distribution was used to judge POGO stability.Furthermore,the suppression effect of different design states of accumulator on POGO vibration was analyzed and compared with that of the critical damping method.Results showed the vector fitting method has a higher accuracy than the critical damping method does;when the accumulator’s PV value is within the range of 0.157-0.196 MPaL,itssuppression effect on POGO vibration is the best;the proposed vector fitting method can provide a reference for suppressing other liquid rockets’POGO vibration.

关 键 词：POGO振动 矢量拟合法 稳态图 蓄压器 

分 类 号：V414.1[航空宇航科学与技术—航空宇航推进理论与工程]