C/SiC陶瓷基梯度点阵复合材料结构传热性能

摘要

针对高速飞行器的防热需求,设计了C/SiC陶瓷基梯度点阵热防护结构.基于离散坐标辐射模型和层流模型,建立了传导、辐射、对流换热耦合条件下梯度点阵结构的三维传热模型,提出了梯度点阵结构传热系数的计算方法.为保证计算方法的正确性,对点阵结构高温传热的数值计算方法进行了对比验证,数值计算结果与实验结果具有很好的一致性.最后探讨了高温环境和材料细观结构尺寸变化对C/SiC陶瓷基点阵结构传热系数的影响,提出了C/SiC陶瓷基梯度点阵结构设计和使用过程中需要重点考虑的因素.%An innovative design of C/SiC sandwich composites with graded lattice cores was proposed for the purpose of thermal protection system of high-speed aircraft.Considering the coupling of heat conduction,heat radiation and heat convection,three-dimensional heat transfer model of the sandwich structure was established based on Discrete Ordinates Radiation Model and Laminar Flow Model.The calculation method for heat transfer coefficient of the graded lattice core sandwich structure was presented.In order to verify the calculation method,the numerical results were compared with the experiment data.The influences of temperature boundary conditions and meso size of the sandwich structure on the heat transfer coefficient were investigated.The key factors to design C/SiC graded lattice core composite sandwich structures were presented.