摘要
硅基复合材料是一种重要的烧蚀热防护材料,在综合考虑了碳-二氧化硅反应、碳的氧化、熔融二氧化硅的流失与蒸发等物理化学反应的基础上,建立了硅基复合材料的新型烧蚀分析模型。首先,利用质量守恒原理、化学平衡定律以及饱和蒸气压方程推导了包含碳-二氧化硅反应在内的壁面气体组分质量分数方程组,然后基于方程组的解计算出不同温度压力下,硅基复合材料烧蚀过程中碳与二氧化硅反应的量占碳消耗总量的比值,进而建立了包含碳-二氧化硅反应的硅基材料烧蚀的质量守恒和能量守恒模型。利用建立的模型计算了不同工况下材料的烧蚀速度,模拟结果与实验值吻合良好,与未考虑碳-二氧化硅反应的前人最新模型相比,平均误差可由10%减小至3%。最后,针对树脂含量对硅基复合材料烧蚀性能的影响进行了研究,结果表明树脂含量约0.5时烧蚀性能最佳。
Silica-reinforced composites are important ablative thermal protection materials.In this paper,a new ablative analysis model of silica-reinforced composites was established based on the comprehensive considerations of a variety of physical and chemical reactions such as carbon-silicon dioxide reaction,carbon oxidation,erosion and evaporation of molten silicon dioxide.First,the concentration equations of gas species in the near wall area considering C-SiO_(2) reaction were derived by using the mass conservation principle,chemical equilibrium law and saturated vapor pressure equation,and then based on the solution of equations under different temperature and pressure,the ratio of carbon reacting with silicon dioxide to total carbon consumption were calculated.Then the mass and energy conservation equations considering C-SiO_(2) reaction were established.The model was used to calculate the ablation velocity of the material under different working conditions.The results showed that the simulation met the experimental data well,and the maximum absolute error of the ablation velocity was only 0.034 mm/s.Finally,the effect of resin content on the ablative properties of silica-reinforced composites was studied,and the results showed that the ablation performance was best when the resin content was about 0.5.
作者
王湘阳
年永乐
刘娜
程文龙
WANG Xiangyang;NIAN Yongle;LIU Na;CHENG Wenlong(Department of Thermal Science and Energy Engineering,University of Science and Technology of China,Hefei 230027,Anhui,China;Hypersonic Vehicle Research Center of Thermal Protection and Insulation,Beijing Institute of Space Long March Vehicle,Beijing 100076,China)
出处
《化工学报》
EI
CAS
CSCD
北大核心
2021年第6期3270-3277,共8页
CIESC Journal
基金
国家自然科学基金项目(51876198,52006211)。
关键词
复合材料
烧蚀
化学反应
气体组分浓度
数值模拟
树脂含量
composites
ablation
chemical reaction
gas component concentrations
numerical simulation
resin content
