随机振动条件火箭贮箱增压系统工作过程仿真

为研究随机振动对贮箱增压系统动态特性和稳定性的影响,引入管路元件壳体坐标实现外激振动的加载,以谐波叠加法模拟飞行环境的随机振动过程,对管路和管路元件分别建立拉格朗日坐标下的一维流动方程和常微分方程组以模拟增压系统动态工作过程,对某贮箱增压系统有/无外界激励振动条件下的工作过程进行了全程计算.计算结果表明:振动环境下减压器、稳压器等运动元件的瞬时流量变化在增压系统中产生压力波动,某些情况下,会导致减压器等出现具有一个主要频率的振荡过程,影响减压器工作稳定性;振动过程中贮箱气枕压力基本不受影响.无振动条件下的计算结果与试验数据基本吻合.提出的模型和方法在贮箱增压系统工作过程仿真中显示了较好的有效性.

Simulation of the working process of launch vehicle pressurization system in random vibration condition

To study the dynamic characteristic and stability of the launch vehicle tank pressurization system working in random vibration condition, harmony superposition method was used to simulate the random process; and component-shell-placement was introduced as vibration excitation to modify the existing model. The gas pipes and components were respectively modeled using the one-dimensional flow equations under the Lagrange reference frame and the ordinary differential equations, working processes of the pressurization system in/without the vibration condition were simulated. In the vibration condition, pressure fluctuation was observed, which may lead to the oscillation of the regulator, and destroy the stability of the component. The vibration presents little conspicuous influence with the ullage pressure during the full course of work. The data of the system working in non-vibration condition was compared to the given test record, a satisfying agreement was reported. The mathematical model and calculating method are validated to be effective in the calculation of the working process of the launch vehicle tank pressurization system.