复合材料在长时间加热条件下的隔热机理

Insulation Mechanism of Composite at Long Time Aeroheating Conditions

结合长时间非烧蚀热防护的技术需求,在固定壁面温度的条件下,对多孔材料传导-辐射耦合传热过程进行了模拟。结果表明:材料的隔热性能与材料的使用环境及内部结构密切相关,减小内部孔隙的特征尺寸,增加材料的密度和固体材料的比率有利于降低隔热材料的等效热导率,并延长材料达到热平衡的时间;同时达到平衡时,材料的背面温升与背面散热条件密切相关。

Heat transfer coupled radiation-conduction for porous materials is simulated and influence factors are analyzed at a constant boundary temperature according to the need of long time non-ablation thermal protection. The results show that the insulation ability is closely related to the working environment and interior structures of the materials. Decreasing the character length of inner structure and increasing the density and the ratio of solid material will be in favor of reducing effective thermal conductivity and extending the time reaching thermal equilibrium. When temperature is in equilibrium,the back temperature increasing will be decided by the boundary heat transfer conditions.