尖化前缘高导热材料防热分析  

Analysis of Sharp Leading-edge Thermal Protection of High Thermal Conductivity Materials

作　　者：孙健[1] 刘伟强[1] 

机构地区：[1]国防科学技术大学航天与材料工程学院,湖南长沙410073

出　　处：《航空学报》2011年第9期1622-1628,共7页Acta Aeronautica et Astronautica Sinica

基　　金：国家自然科学基金(90916018);高等学校博士学科点专项科研基金(200899980006)~~

摘　　要：针对飞行器高超声速飞行时严重的气动加热环境,提出疏导式热防护结构(TPS),为飞行器前缘提供热防护。采用有限元法和有限体积法,分别对在特定工况下飞行的尖化前缘固体域和流体域进行计算,验证了前缘内嵌高导热材料的防热效果,其中来流马赫数为6.5时,头部壁面最高温度下降了13.6%,尾部最低温度升高了16.7%,实现了热流由高温区向低温区的转移,削弱了前缘头部的热载荷,强化了前缘的热防护能力。对于耐热材料提出一个最佳厚度值,即综合考虑厚度增加带来额外的热载荷,在保证热结构稳定的同时选取最小厚度。对耐热材料黑度和高导热材料的导热系数对壁面温度的影响进行了讨论,为尖化前缘防热材料的选取提供了一定的参考依据。The structure of leading thermal protection is considered as thermal protection system （TPS） to prevent hypersonic vehicle from the serious aerodynamic heating. By the use of finite element method and finite volume method, we calculate the solid domain and fluid domain of sharp leading-edge which is flying under given conditions. And it is proved that high thermal conductivity materials which are embedded in the leading-edge have an effect on thermal protection. The maximum temperature of the head decreases by 13.6%, and the minimum temperature of after-body increases by 16.7% when Mach number is 6.5. The transfer of heat from head to after-body is achieved, the front head of the thermal load is weakened and the ability of leading-edge thermal protection is strengthened. Considering that heat loading increases with increase of thickness, we propose the optimal thickness value of heat-resistant material which is the minimum value that can ensure the thermal structural stability of sharp leading-edge. The effects of black level of heat-resistant materials and thermal conductivity of high-conductivity materials on the wall temperature are discussed, which provides some references for the selection of thermal protection materials of sharp leading-edge.

关 键 词：疏导式热防护 气动热 前缘 高导热材料 耐热材料 

分 类 号：V211.3[航空宇航科学与技术—航空宇航推进理论与工程]