【作者】 谭述君； 陈宇； 王庆伟； 吴志刚；

【Author】 Tan Shu-jun;Yu Chen;Wang Qing-wei;Wu Zhi-gang;School of Aeronautics and Astronautics,Dalian University of Technology;State Key Laboratory of Structural Analysis for Industrial Equipment;Beijing Aerospace System Engineering Institute;

【机构】 大连理工大学航空航天学院； 工业装备结构分析国家重点实验室； 北京宇航系统工程研究所；

【摘要】 针对Rubin建立的Pogo模型的奇异性和冗余性问题,本文提出了一种改进的Rubin模型。区别于Rubin基于基本物理单元建模的方法,我们提出了基于独立流量位移的建模机理,将组成推进系统的基本物理单元通过重新划分或组合导出九类独立单元,然后利用相邻单元节点处的脉动压力相等作为连接条件,建立了推进系统的微分方程,进一步耦合结构振动方程导出了POGO回路的微分方程模型。该模型不含代数方程,可直接应用于频域分析和时域仿真,而且该模型的维数降低了近一半,提高了数值计算的效率和稳定性。利用局部编号与节点编号的映射关系,该模型中的系数矩阵可以通过程序自动生成,大大提高了建模的效率和准确性。最后通过对CZ-2F火箭POGO回路的建模、分析和仿真,验证了该方法的正确性和实用性。更多还原

【Abstract】 A new modelling method for deriving differential equation form model of Pogo system is presented in this study.Firstly the dynamic characteristics of basic physical elements of the liquid propulsion system are studied.The classification mechanisms based on the description of independent weight-displacements are proposed and nine basic independent elements are derived by the division and combination of the basic physical elements.Then the differential equations of propulsion system are established using the assembly conditions that the perturbational pressures on the nodes are equal to each other.The Pogo system model in differential equation form is then obtained by coupling the structure vibration equations and the propulsion system equations.The Pogo system equations derived contain no algebraic equations,which can be directly used for frequency-domain analysis and time-domain simulation.Moreover,since the state variables do not contain the perturbational pressures,the dimension of the equations is reduced almost half of that of Rubin’s,which significantly improves the numerical computation efficiency and stability.Finally,the analysis results of a certain type of liquid rocket of China confirm the correctness and practicability of the modelling method in this study.更多还原