液体火箭推进系统频率特性的灵敏度分析

针对液体火箭飞行过程中POGO振动对火箭系统的不利影响，建立了液体火箭推进系统动力学模型，以区间数学为理论基础，对推进系统频率特性进行灵敏度分析，得到了推进系统的流体惯性、阻力和刚度参数对推进系统频率特性的影响规律。研究结果表明：液体火箭推进系统振动频率对流体惯性参数的敏感程度比流体阻力参数和流体刚度参数明显大，泵前短管流体惯性的变化对推进系统振动频率的影响最大，补偿管路流体刚度的变化对推进系统振动频率的影响最小。为合理设计推进系统的动力学参数，降低推进系统的振动频率，抑制 POGO 振动的发生提供理论依据。

Sensitivity Analysis of Frequency Characteristic for Propulsion System in Liquid Rocket

For POGO vibration has the disadvantage effect on the rocket system in the flight course of a liquid rocket, the dynamics model of propulsion system in liquid rocket is established, the sensitivity of frequency characteristic for the propulsion system is analyzed based on interval mathematics, laws of effects of inertial parameters, drag parameters and stiffness parameters of fluid in the propulsion system on frequency characteristic of the propulsion system are obtained. The results show that the sensitivity of the vibration frequency of the propulsion system to inertial parameters of fluid is sharply greater than the drag parameters and stiffness parameters of fluid, the influence of the variation of fluid inertia of the short pipeline in pump front on the vibration frequency of the propulsion system is the maximum, the influence of the variation of fluid stiffness of the compensating pipeline on the vibration frequency of the propulsion system is the minimum. This provides a theoretical basis for reasonably designing dynamics parameters of propulsion system, reducing the vibration frequency of propulsion system and suppressing the occurrence of POGO vibration.