Modeling and prediction of the effective thermal conductivity of random open-cell porous foams
Modeling and prediction of the effective thermal conductivity of random open-cell porous foams
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DOI：
10.1016/j.ijheatmasstransfer.2007.11.031
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发表时间：
2008-03
影响因子：
5.2
通讯作者：
Moran Wang;N. Pan
中科院分区：
文献类型：
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作者：
Moran Wang;N. Pan
尽管非常理想，但高孔隙率开孔多孔泡沫材料的有效热导率的准确预测仍然是一个具有挑战性的问题。针对这一棘手的障碍，我们开发了一种随机生成-生长方法，通过计算机建模再现开孔泡沫材料的微观结构，然后使用高效的格子Boltzmann方法求解通过复杂结构的能量输运方程。贡献。因此，开孔泡沫材料的有效导热系数的数值计算和预测与现有的实验数据进行了比较。由于孔隙率高，当任一组分的热导率非常低且辐射传热不可忽略时，由热传导引起的预测热导率低于测量数据。在考虑了辐射效应后，数值计算结果与实验结果吻合较好。随着材料孔隙率的减小，辐射的影响逐渐减小。通常，开孔泡沫材料的有效导热率比相同组分的颗粒材料的有效导热率高得多，这是由于泡沫材料的内部网状形态增强了传热。
Although highly desirable, accurate prediction of the effective thermal conductivity of high-porosity open-cell porous foam materials has remained to be a challenging problem. Aiming at this thorny obstacle, we have developed a random generation-growth method to reproduce the microstructures of open-cell foam materials via computer modeling, and then solve the energy transport equations through the complex structure by using a high-efficiency lattice Boltzmann method in this contribution. The effective thermal conductivities of open-cell foam materials are thus numerically calculated and the predictions are compared with the existing experimental data. Since the porosity is high, the predicted thermal conductivity caused by thermal conduction is lower than the measured data when the thermal conductivity of either component is very low and the radiation heat transfer is non-negligible. After considering the radiation effect, the numerical predictions agree rather well with the experimental data. The radiation influence is diminishing as the material porosity decreases. In general the effective thermal conductivity of open-cell foam materials is much higher than that of granular materials of the same components due to the enhanced heat transfer by the inner netlike morphology of the foam materials.