低温液体火箭发动机高压静密封有限元分析

以某型号液体火箭发动机的推力室燃料阀出口法兰静密封结构为研究对象,针对法兰连接结构特点,运用有限元方法建立了管路-阀门-推力室模型,通过热-结构耦合计算分析表明:在温度和压力的共同作用下,推力室燃料阀出口法兰变形导致密封面微小分离,造成垫片局部压紧应力大幅减小,可能引起推进剂泄漏并起火。在通过上述分析定位泄漏原因并预测泄漏率之后,又建立了参数化的螺栓-法兰-垫片密封性分析局部模型,基于柔性石墨垫片的基本性能试验数据,计算分析了垫片厚度、螺栓预紧力等结构因素对静密封性能的影响,理论上验证了增加预紧力,增厚密封垫片等密封改进措施的有效性。

FEM analysis on high-pressure static sealing of low-temperature liquid rocket engine

The hydrogen valve outlet flange static sealing in X-type LOX/LH rocket engine is mainly focused in this paper.An integrated pipe-valve-chamber 3D model is built based on finite element method.According to the result of thermal-structural coupling analysis,the deformation of the valve flange brings on a small separation between the sealing couple,which causes abrupt decrease of the gasket stress and eventually results in the leakage and fire.A parametric partial flange-bolt-gasket FEM model is generated to analyze the sealability.Different values of structural parameters are separately issued on models to reveal the influence of each single parameter to the flange sealability,which verifies the measures including increasing bolt-pretension and thickening the gasket are theoretically effective.