液氧煤油发动机单向阀自激振荡特性  

Self-excited oscillation characteristics of check valve of LOX/kerosene engine

作　　者：陈一丹 陈宏玉 CHEN Yidan;CHEN Hongyu(Science and Technology on Liquid Rocket Engine Laboratory,Xi'an Aerospace Propulsion Institute,Xi'an 710100,China)

机构地区：[1]西安航天动力研究所液体火箭发动机技术重点实验室,陕西西安710100

出　　处：《火箭推进》2021年第5期35-41,共7页Journal of Rocket Propulsion

基　　金：国家自然科学基金(51606138)。

摘　　要：针对液氧煤油发动机系统中液氧单向阀流路在某次试车中出现的振动问题,建立了单向阀流路工作过程的数学模型,提出了求解推进剂管路瞬变流控制方程的Fourier谱方法;基于新的面向对象Modelica语言,搭建起了液氧单向阀流路瞬态特性研究的模块化仿真模型,并进行了仿真计算。通过对阀前压力添加阶跃扰动的方法实现液氧单向阀阀芯打开过程持续自激振荡。借助仿真计算的方法,分析了造成单向阀自激振荡的原因,阐明了不同流体介质和各设计参数对单向阀工作稳定性的影响。结果表明:液氧路单向阀自激振荡时,阀前压力和流量均出现持续振荡,且振荡频率约为725 Hz。单向阀自激振荡过程是由瞬态液动力和弹簧弹力耦合作用主导。减小工质密度、减小节流孔直径、减小阀芯行程和调整阀前后节流孔压降都有助于抑制阀芯的振动。The transient model of check valve flow-path system used in a staged combustion cycle LOX/kerosene engine system was established.The partial differential equations governing the unsteady flow of propellant pipelines were solved by the Fourier spectral method.A modularization model of a characteristic research system for check valve flow-path system was established based on Modelica language.The continuous self-excited oscillation of the open process of the liquid oxygen check valve core was realized by adding step disturbance to the pressure in front of the valve.Then aiming at the instabilities observed during testing operation,the influences of several structural and control parameter on the stability of check valve were clarified by a series of simulation.The results show that during the self-excited oscillation of the liquid oxygen check valve,the pressure and flow rate in front of the valve oscillate continuously,and the oscillation frequency is close to about 725 Hz.The process of self-excited oscillation of check valve may be dominated by transient hydrodynamic and spring elastic coupling.Those measures which can improve the dynamic stability include:increasing the mass of valve spool,reducing the size of orifice,increasing the stiffness of diaphragm.The comparison with the experimental results confirms the effectiveness and feasibility of some measures.

关 键 词：液体推进剂火箭发动机 单向阀 自激振荡 数值仿真 试验验证 MODELICA 

分 类 号：V433[航空宇航科学与技术—航空宇航推进理论与工程]