大温差测试条件下热防护材料高温导热系数试验方法

热防护材料高温导热系数是进行高超声速飞行器设计不可或缺的参数。通过热防护材料导热系数理论分析以及传统稳态法试验原理数学推导,说明了热防护材料导热系数物理本质。探讨了试验温差对热防护材料导热系数测试的重要性和传统稳态法在测试热防护材料高温导热系数时的技术局限性。基于热防护材料内部温度分层特征以及导热系数-温度非线性关系函数形式直接假设,提出并分析证明了两种适用于大温差测试条件的热防护材料高温导热系数试验方法。对热防护材料高温导热系数获取有重要的参考价值。

Experimental Method of High Temperature Thermal Conductivity of Thermal Protection Materials Under The Big Temperature Difference Test Conditions

High temperature thermal conductivity of thermal protection materials are key parameters when hypersonic vehicles are designed. In this paper physical essence of thermal protection materials thermal conductivity is revealed based on its theoretical analysis, the importance of temperature difference between hot side and cold side on test samples and technical limitations of traditional steady-state thermal conductivity measurements are investigated by researching general experimental principles. According to the Layered characteristic of temperature in test samples and the function hypothesis of nonlinear relations between thermal conductivity and temperature, two test methods of high temperature thermal conductivity of thermal protection materials which are suitable for big temperature difference test conditions are proposed and proved.