【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。更多还原

【Abstract】 To investigate the unsteady-state outgassing mechanism of residual gases within the Multi-Layer Insulation( MLI) of cryogenic, this study developed a simulated experimental platform 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 design, aperture layout strategies, and spacer materials, on the transient release dynamics of rarefied gases within the MLI. The results indicate that the relaxation time of MLI outgassing is extremely 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 increase depending on the configuration of the spacers. The MLI design with central circular apertures 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 structures was significantly lower than that of the serrated MLI under the same outgassing period.更多还原