C/C喉衬热化学烧蚀的高维不确定量化分析

High-Dimensional Uncertainty Quantification of Thermochemical Ablation for C/C Throat Insert

关键词:  固体火箭发动机  喷管  喉衬  烧蚀  参数分析  量化分析

Key words:  Solid rocket motor  Nozzle  Throat insert  Ablation  Factor analysis  Quantitative analysis

摘要:

为了定量化地评估固体火箭发动机喷管喉衬烧蚀这一复杂物理化学过程中，不同因素相互制约或激励对喉衬烧蚀整体情况产生的耦合影响，并探寻影响喉衬烧蚀率的关键因素，应用自主研发的高维不确定量化算法研究了燃烧室压强、燃气比热比等7个因素对烧蚀的耦合影响规律，并通过全局敏感度分析技术探究了不同关键因素对烧蚀率变化的贡献程度。研究发现：就烧蚀模型物理机制本身而言，影响烧蚀率的关键因素为燃气比热比、喉部马赫数和燃烧室温度。考虑实验实际中相关物理量的不确定性输入后，燃烧室压强由于自身较大的不确定度输入成为影响烧蚀率的首要因素。

Abstract:

In order to quantitatively estimate the coupling constraint or stimulus effects of different factors on the throat ablation and to explore the major factors to the throat ablation rates in the intricate physical and chemical process of SRM nozzle throat ablation， the self-developed high-dimensional uncertainty quantification algorithm， which effectively solves the curse of dimensionality was applied. The study on coupling influence law of 7 factors， including combustion chamber pressure and gas specific heat ratio， was conducted. Their contributions to the ablation rates were also investigated by using the global sensitivity analysis. As a result， in the physical mechanism of the ablation model， the gas specific heat ratio， the throat Mach number and the gas temperature are the key factors， while after counting in the uncertainty inputs in the practical experiment， the combustion chamber pressure becomes to the primary factor because of its large uncertainty.