摘要
为研究液体火箭发动机低温阀门铝垫片密封结构在低温工作环境下的密封性能,利用ABAQUS软件建立了该结构的二维轴对称模型,计算了低温工作状态下铝垫片密封表面接触压力的变化,并研究了铝垫片在循环温度载荷作用下接触压力下降的机理。结果表明,在低温工作时,密封垫片与阀门各部件材料线胀系数不同,导致在温度降低时密封面上接触力下降;而铝垫片密封表面上复杂的应力应变状态导致接触压力在温度载荷作用下无法恢复。在温度载荷循环作用下,铝垫片密封面上产生了棘轮效应。垫片的塑性应变在棘轮效应中累积,且最大应力值在棘轮效应中下降;接触力会随着温度载荷循环次数增加逐步降低并在一定周期后保持稳定。提出了采用锥形垫片的结构改进方案,并通过仿真验证了该结构在循环温度载荷作用下保持密封压力的有效性。
In order to study the sealing performance of aluminum gasket sealing structure for cryogenic valve of a liquid rocket engine under low temperature environment,a two-dimensional axisymmetric model of the sealing structure was established by ABAQUS software.Contact pressure of aluminum gasket seal surface under low temperature working condition was calculated,and the mechanism of contact pressure drop of aluminum gas⁃ket under cyclic temperature load was studied.The results show that the contact pressure on the sealing surface decreases at low temperature due to the different linear expansion coefficient between the sealing gasket and vari⁃ous parts of the valve,while the complex stress-strain state on the sealing surface of aluminum gasket leads to the failure of contact pressure recovery under temperature load.The ratchet effect is produced on the sealing surface of aluminum gasket under the cyclic temperature load.The plastic strain of the gasket accumulates in the ratchet⁃ing effect,and the maximum stress decreases in the ratcheting effect.The contact force decreases gradually with the increase of temperature recycle times,and remains stable after a few period.In addition,an improved struc⁃ture of sealing gasket by using conical gasket is proposed,and the effectiveness of the structure to maintain the sealing pressure under the cyclic temperature load is verified by simulation.
作者
张京东
刘博
许健
廖日东
ZHANG Jing-dong;LIU Bo;XU Jian;LIAO Ri-dong(School of Mechanical Engineering,Beijing Institute of Technology,Beijing 100081,China;Beijing Aerospace Propulsion Institute,Beijing 100074,China)
出处
《推进技术》
EI
CAS
CSCD
北大核心
2021年第8期1898-1905,共8页
Journal of Propulsion Technology
关键词
液体火箭发动机
低温阀门
密封垫片
接触压力
温度载荷
Liquid rocket engine
Cryogenic valve
Sealing gasket
Contact pressure
Temperature load
