一种计算泡沫金属等效热导率的新模型

摘要

A new model for calculating effective thermal conductivities of different metal foams is proposed based on an appropriate geometrical modeling method. The geometrical modeling is based on the representative cell geometry of metal foam, Kelvin tetrakaidecahedron, and the foam ligament is geometrically represented by concave tri-prism. The characteristic of foam node is also taken into account in the model. A general expression for calculating effective thermal conductivity is derived from thermal resistance analysis. In the present model, no geometrical parameter needs to be determined through experiments to describe the relationship between foam ligament and node. Compared with available experimental data and semi-empirical models in literature, the present model can accurately predict the effective thermal conductivities of different metal foams saturated with different mediums, with the average relative deviations from the experimental data within 10%. Considering both accuracy and generality, the present model is superior to existing semi-empirical models.%提出一种针对泡沫金属等效热导率预测的新模型，该模型基于泡沫金属Kelvin十四面体元胞结构建模，以凹面三棱柱近似金属韧带，并考虑韧带交汇处的结点特点，通过热阻分析得到计算等效热导率的表达式。研究表明：该模型对充填不同介质的不同材质泡沫金属等效热导率均有较高的预测精度（平均偏差均小于10%），与文献其他半经验模型相比能更好兼顾预测精确性和通用性。