多脉冲固体火箭发动机长尾喷管多层热防护结构传热烧蚀特性  

Heat transfer and ablation characteristics of multi-layer thermal protection structure for long tail nozzle of multi pulse solid rocket motor

作　　者：何振川 李映坤 武炎 陈雄[1] 薛海峰[1] HE Zhenchuan;LI Yingkun;WU Yan;CHEN Xiong;XUE Haifeng(Key Laboratory of Special Engine Technology,Ministry of Education,School of Mechanical Engineering,Nanjing University of Science and Technology,Nanjing 210094,China)

机构地区：[1]南京理工大学机械工程学院特种动力技术教育部重点实验室,江苏南京210094

出　　处：《推进技术》2025年第2期200-212,共13页Journal of Propulsion Technology

基　　金：国家自然科学基金(52006099);江苏省自然科学基金(BK20220954)。

摘　　要：针对多脉冲固体火箭发动机长尾喷管热防护结构的传热烧蚀问题,提出了由C/C抗烧蚀层、碳/酚醛相变吸热层和钢壳体结构组成的多层热防护结构,建立了基于热物性参数随时间和温度变化的传热烧蚀数学模型,采用有限差分隐式格式进行求解。在验证了多层防热结构传热烧蚀计算框架准确性的基础上,开展了长尾喷管多层热防护结构传热烧蚀响应过程仿真研究,分析了脉冲间隔时间对多层热防护结构传热烧蚀响应的影响规律。研究结果表明:与传统固体火箭发动机相比,多脉冲发动机工作时碳/酚醛层内热物性参数与热解反应变化较大,导致多层结构内能量分布更加均匀,使得钢壳体外表面温度显著升高,同时C/C抗烧蚀层表面烧蚀量显著下降;随着脉冲间隔时长的增加,C/C抗烧蚀层烧蚀量逐渐下降,碳/酚醛层内热解程度逐渐降低,钢壳体外表面温度先升高后下降,脉冲间隔时长60 s时钢外壳表面温度达到最大值。In order to mitigate the heat transfer and erosion issues of the long tail nozzle thermal protectionstructure for multi-pulse solid rocket motors, a novel multi-layer thermal protection structure is proposed. Theproposed structure consists of a C/C anti-erosion layer, a carbon/phenolic phase change heat absorbing layer,and a steel shell structure. Furthermore, a mathematical model is established to investigate the heat transfer anderosion characteristics of this multi-layer thermal protection structure. The model accounts for the effects of timeand temperature variations on the thermal physical parameters of the material. A finite difference implicit formatis employed to numerically solve the governing equations describing the heat transfer and erosion phenomena.Based on the validation of the precision of the heat transfer and ablation computational framework utilized formulti-layer thermal protection configurations, an investigation was carried out to simulate the heat transfer andablation response mechanisms of multi-layer thermal protection structures featuring extended tail nozzles. Fur⁃thermore, an analysis was performed to assess the impact of pulse interval duration on the heat transfer and abla⁃tion responses of these multi-layer thermal protection structures. The findings of this research suggest that in con⁃trast to conventional solid rocket motors, multi-pulse motors demonstrate substantial alterations in thermal char⁃acteristics and pyrolysis reactions occurring within the carbon/phenolic layer during operation, leading to a morehomogeneous energy distribution across the multi-layer configuration and a marked elevation in surface tempera⁃ture external to the steel casing. Concurrently, there is a notable reduction in the surface ablation rate of the C/Cablation-resistant layer. With the prolongation of pulse interval duration, the rate of degradation of the C/C abla⁃tion-resistant layer gradually diminishes, the extent of thermal decomposition within the carbon/phenolic layergradually redu

关 键 词：多脉冲固体火箭发动机 喷管 传热 烧蚀 热防护结构 

分 类 号：V231.1[航空宇航科学与技术—航空宇航推进理论与工程]