基于流固耦合的固体发动机复合喷管烧蚀型面演变  

Ablative surface evolution of solid rocket motor composite nozzles based on fluid-solid coupling

作　　者：陈旭龙 闫航 张春宇 冯喜平[1] 侯晓[1] CHEN Xulong;YAN Hang;ZHANG Chunyu;FENG Xiping;HOU Xiao(Science and Technology on Combustion,Internal Flow and Thermo-Structure Laboratory,Northwestern Polytechnical University,Xi’an 710072,China)

机构地区：[1]西北工业大学燃烧、热结构与内流场重点实验室,陕西西安710072

出　　处：《推进技术》2024年第7期113-123,共11页Journal of Propulsion Technology

摘　　要：由于材料烧蚀性能不同,固体火箭发动机复合喷管普遍存在烧蚀台阶,严重影响喷管结构完整性,降低喷管性能。为了预示固体火箭发动机复合结构喷管内不同热防护材料交接处的烧蚀台阶型面演变过程,建立了一种能反映喷管两相流环境下防热材料烧蚀过程的流固耦合计算方法。依据热化学烧蚀与粒子侵蚀机理,考虑瞬态计算中烧蚀型面的退移,模拟了石墨-高硅氧/酚醛复合喷管烧蚀型面演化过程,验证了计算方法的有效性。模拟得到的收敛段烧蚀台阶型面与实验结果吻合较好,扩张段台阶计算深度略低于实验值。仿真结果表明:收敛段受热化学烧蚀与粒子侵蚀共同作用,两种材料粒子侵蚀速率的差异可达0.36 mm/s,是收敛段烧蚀台阶形成的主要原因,扩张段烧蚀台阶的产生仅受热化学烧蚀的影响,交接处退移速率最大差值为0.044 mm/s;烧蚀台阶形成后,拐角处暴露的石墨材料会受到较强的粒子冲刷效应;喷管喉部前端的石墨材料因烧蚀型面变化,喷管实际喉部向出口移动1.96 mm。Due to the different ablation properties of the materials,ablation steps are common in composite nozzles of solid rocket motors,which seriously affects the structural integrity of the nozzle and reduces the nozzle performance.In order to predict the evolution of the ablation step pattern at the intersection of different thermal protection materials in the composite nozzle of a solid rocket motor,a fluid-solid coupling calculation method was developed to reflect the ablation process of thermal protection materials in the two-phase flow environment of the nozzle.Based on the mechanism of thermochemical ablation and particle erosion,the evolution process of the ab-lative surface of graphite-high silica phenolic compound nozzle was simulated by considering the regression of the ablative surface in the transient calculation,and the effectiveness of the calculation method was verified.The sim-ulated ablative step of convergence section was in good agreement with the experimental results,while the calcu-lated step depth of expansion section was lower than the experimental value.Simulation results show that:the convergent section is subjected to a combination of thermochemical ablation and particle erosion,the difference in particle erosion rate between the two materials up to 0.36 mm/s,which is the main reason for the formation of ablation steps in the convergence section.The generation of ablation steps in the expansion section is only affect-ed by thermochemical ablation,the maximum difference in receding rate at the intersection is 0.044 mm/s.After the formation of ablation steps,the exposed graphite material at the corners will be subject to a strong particle scouring effect.The actual throat of the nozzle moves 1.96 mm towards the outlet due to ablation of the graphite material at the front of the nozzle throat.

关 键 词：固体火箭发动机喷管 烧蚀台阶 热化学烧蚀 粒子侵蚀 数值仿真 

分 类 号：V435[航空宇航科学与技术—航空宇航推进理论与工程]