多层绝热微腔内非稳态放气特性实验研究  

Experimental study on unsteady evacuation in multilayer insulation microcavities

作　　者：于洋 谢福寿 厉彦忠[1] Yu Yang;Xie Fushou;Li Yanzhong(Institute of Refrigeration and Cryogenic Engineering,Xi’an Jiaotong University,Xi’an 710049,China)

机构地区：[1]西安交通大学制冷与低温工程系,西安710049

出　　处：《低温工程》2024年第5期57-66,共10页Cryogenics

基　　金：国家自然科学基金资助项目(51906184、52276018);中国博士后科学基金资助项目(2021T140538、2020M673391)。

摘　　要：为了剖析低温火箭上面级的多层绝热(MLI)内残余气体的非稳态排放机制,设计了一套仿火箭升空/在轨瞬态变化模拟实验台,分析了孔隙群的结构设计、开口布局策略和间隔物的材料等参数对MLI内稀薄气体瞬态释放动态的复杂影响。结果表明:MLI放气的弛豫时间十分缓慢,在仿飞行环境中持续放气超过270小时,最大层间压强依然大于约2 Pa。侧面反映出,MLI存在显著的残余气体寄生漏热问题。随着放气时长的延长,不同间隔物配置的MLI内压强差异逐渐增大。中心圆孔设计的MLI在放气效率上展现出明显优势,相较于偏离中心和边缘打孔的设计。此外,在相同的放气周期内,圆孔和一维缝隙结构的平均压强显著低于锯齿形MLI。To investigate the unsteady-state outgassing mechanism of residual gases within the Multi-Layer Insulation(MLI)of cryogenic,this study developed a simulated experimental plat-form that mimics the transient changes experienced during rocket launch and orbit.The platform was used to analyze the complex impacts of various parameters,such as pore group structure de-sign,aperture layout strategies,and spacer materials,on the transient release dynamics of rare-fied gases within the MLI.The results indicate that the relaxation time of MLI outgassing is ex-tremely slow,with outgassing persisting for over 270 hours and the maximum interlayer pressure remaining above approximately 2 Pa.This observation highlights a significant issue of parasitic heat leakages.As outgassing duration increases,the pressure differences within the MLI also in-crease depending on the configuration of the spacers.The MLI design with central circular aper-tures demonstrated a clear advantage in outgassing efficiency compared to designs with off-center or edge apertures.Additionally,the average pressure of circular and one-dimensional slit struc-tures was significantly lower than that of the serrated MLI under the same outgassing period.

关 键 词：多层绝热 升空 / 在轨过程 残余气体 瞬态放气特性 

分 类 号：V511.6[航空宇航科学与技术—航空宇航推进理论与工程]