Estimation of temperature-dependent thermal conductivity and specific heat capacity for charring ablators
Estimation of temperature-dependent thermal conductivity and specific heat capacity for charring ablators
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DOI：
10.1016/j.ijheatmasstransfer.2018.10.014
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发表时间：
2019-02
影响因子：
5.2
通讯作者：
Xiaomin Wang;Li-Song Zhang;Chi-Chain Yang;Na Liu;W. Cheng
中科院分区：
文献类型：
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作者：
Xiaomin Wang;Li-Song Zhang;Chi-Chain Yang;Na Liu;W. Cheng
热性能的准确评估是炭化材料模拟和设计的关键。在这项工作中，一个新的反演方法来估计温度依赖的热导率和比热容的温度数据炭化烧蚀。首先，建立了考虑表面凹陷的一维烧蚀材料热响应模型，模拟了炭化烧蚀材料的热行为。在此基础上，通过敏感性分析研究了热物性参数与温度的相关性，确定了反演序列，发现原始热导率对温度的影响最大，应首先估算原始热导率。最后，由温度数据反演得到了随温度变化的导热系数和比热容。由模拟温度数据反演的导热系数平均误差为4.3%，比热容平均误差为3.1%，与参考值吻合较好。利用热物性反演得到的热响应温度与电弧喷射试验数据吻合较好，平均误差为8.5%。该反演方法可以准确确定导热系数和比热容等与温度相关的未知热性能，为航天器热防护材料的分析和设计提供了参考。
The accurate assessment of thermal properties is crucial for charring materials simulation and design. In this work, a new inversion method for estimating temperature-dependent thermal conductivity and specific heat capacity from temperature data is presented for charring ablators. Firstly, a one-dimensional thermal response model with surface recession is developed to simulate the thermal behavior of charring ablator. Then based on the developed model, sensitivity analysis is conducted to investigate the correlation between thermal parameters and temperature for determining inversion sequence and find that virgin thermal conductivity has the biggest influence on temperature which should be estimated at first. Finally, the temperature-dependent thermal conductivities and specific heat capacities are obtained by the inversion method from temperature data. The inversion values from simulation temperature data coincide with the reference values, which the average inversion error of thermal conductivities is 4.3% and the average inversion error of specific heat capacities is 3.1%. And the calculated thermal response temperature employing the inversion thermal properties shows a good agreement with the arc jet test data, which the average error is 8.5%. This inversion method can accurately determine unknown temperature-dependent thermal properties such as thermal conductivity and specific heat capacity, which provides an insight into the analysis and design of thermal protection materials for spacecraft.