高超声速飞行器热防护系统分析与数值计算

 针对大气环境内吸气式高超声速飞行器热防护要求,得出前缘、下表面和上表面的热防护结构应分别采用碳/碳(C/C)防热材料、刚性陶瓷防热瓦材料和柔性隔热毡材料。基于Abaqus 分析软件建立以机身为主的热分析有限元模型,计算了高超声速飞行器在典型气动加热载荷情况下的温度场分布和在整个飞行过程中温度的变化情况。通过温度分布得到机身前缘的峰值温度达1637℃,上下表面峰值温度分别为635、805℃,验证了本研究提出的热防护结构形式的有效性。通过温度与时间曲线得出飞行500 s 左右时,飞行器前缘及上下表面温度急剧增加、温度梯度大,500~1500 s 期间持续高温,在1500 s 后温度迅速降低。同时建立了C/C、陶瓷瓦及柔性隔热毡3 种典型耐高温材料的传热模型,对其防热结构的防热效率进行评估,得到其最佳的防热材料厚度为57.6、52.9、53.3 mm,可为防热结构的设计提供参考。

Analysis and numerical simulation of the hypersonic vehicle thermal protection structure

Carbon/carbon (C/C) materials, heat-resistant rigid ceramic tiles and flexible felt were used for the leading edge, lower surface and upper surface of airbreathing hypersonic vehicles to meet thethermal protection requirement. The thermal analysis finite element model of hypersonic vehicles was established using Abaqus. The temperature distribution and the changes during the entire flight of the vehicle under typical aerodynamic heating were calculated. The peak temperature of the leading edge was 1637℃, and the peak temperatures for the upper and lower surfaces were 635 and 805℃, verifying the effectiveness of the proposed thermal protection structure. The temperature- time curve shows that the temperature of the leading edge and upper and lower surfaces increased significantly at 500 s with a largetemperature gradient. From 500 s to 1500 s, the temperature was continuously high. The temperature decreased rapidly after 1500 s. The heat transfer models were built for evaluating the efficiency of the three typical thermal protection structures. The optimum thicknesses for the materials were obtained as 57.6, 52.9, and 53.3 mm, which may provide references for the design of thermal protection systems.