非平衡气动加热条件下的材料热响应差异研究

发布时间：2018-01-21 16:29

本文关键词： 复合材料碳/碳超高温陶瓷非平衡流场烧蚀试验　出处：《材料科学与工艺》2017年06期 　论文类型：期刊论文

【摘要】：针对风洞烧蚀试验中碳/碳与超高温陶瓷两种复合材料存在热响应差异的问题,本文从材料壁面催化与非平衡流场气动加热的机理出发,基于两种风洞设备设计了3个烧蚀试验状态,并对可能影响材料热响应的重要因素进行了分析.结果表明:在不同试验设备条件下,碳/碳端头驻点温度差异主要是由试验状态调试偏差和温度测量偏差造成的,而超高温陶瓷端头驻点温度的差异主要是由不同条件气流非平衡度不同、试件表面实际接受的热流不同造成;对碳/碳材料而言,由于其壁面催化特性接近完全催化壁面,在试验设备选择或状态调试时,可以不必考虑流场非平衡度的影响;而对于超高温陶瓷材料,在试验设备的选择上,则需要结合风洞非平衡流场特点,对试验考核的有效性做充分评估.相关结论可为碳/碳、超高温陶瓷复合材料防热性能的考核与评价提供参考与借鉴.
[Abstract]:In view of the difference of thermal response between carbon / carbon and ultra-high temperature ceramic composites in wind tunnel ablation test, the mechanism of aerodynamic heating in the material wall catalysis and non-equilibrium flow field is discussed in this paper. Based on two kinds of wind tunnel equipment, three ablation test states are designed, and the important factors that may affect the thermal response of materials are analyzed. The results show that: under different test equipment conditions. The difference of the stop point temperature of the carbon / carbon terminal is mainly caused by the test state adjustment deviation and the temperature measurement deviation, while the difference of the stop point temperature of the ultra-high temperature ceramic terminal is mainly caused by the different air flow unbalance degree under different conditions. The heat flux actually accepted on the surface of the specimen is different. For the carbon / carbon material, because the catalytic property of the wall is close to that of the complete catalytic wall, the influence of the non-equilibrium degree of the flow field should not be considered when the test equipment is selected or the state is adjusted. For ultra-high temperature ceramic materials, in the selection of test equipment, it is necessary to combine the characteristics of wind tunnel non-equilibrium flow field to make a full evaluation of the effectiveness of the test. The relevant conclusion can be carbon / carbon. The assessment and evaluation of the thermal resistance of ultra-high temperature ceramic composites provide reference and reference.
【作者单位】：国防科学技术大学航天与材料工程学院;北京临近空间飞行器系统工程研究所;
【基金】：国家自然科学基金资助项目(51506008)
【分类号】：TB332
【正文快照】： 碳/碳复合材料具有强度高、抗热冲击性能优异、高热流条件下抗烧蚀性好等优点,是国内外航天器结构与热防护设计中广泛使用的一种复合材料.超高温陶瓷材料是一种高熔点硼化物、碳、氧化物组成的多元复合陶瓷材料,也是各国都在大力发展的新型抗氧化防热材料.近年来,国内外学者针

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