The prediction of effective thermal conductivities perpendicular to the fibres of wood using a fractal model and an improved transient measurement technique
The prediction of effective thermal conductivities perpendicular to the fibres of wood using a fractal model and an improved transient measurement technique
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DOI：
10.1016/j.ijheatmasstransfer.2006.03.027
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发表时间：
2006-10
影响因子：
5.2
通讯作者：
Li-Wu Fan;Ya-cai Hu;Tian Tian-Tian;Zitao Yu
中科院分区：
文献类型：
--
作者：
Li-Wu Fan;Ya-cai Hu;Tian Tian-Tian;Zitao Yu
利用扫描电镜图像分析了木材样品垂直于纤维截面上的多孔微观结构。分别用盒计数法计算图像的分形维数。它们都近似等于1.4，尽管木纤维的分布和尺度非常不同。然后，利用热阻法建立了预测木材有效导热系数的分形模型。此外，我们通过改进的瞬态平面源测量方法测量了木材的有效导热系数。该模型的计算结果与实验数据和文献数据吻合较好。对比结果表明，该分形模型可以准确有效地预测木材垂直于纤维方向的有效导热系数。
The porous microstructure of wood samples on their sections perpendicular to the fibres were analyzed using the scanning electron microscope images. The fractal dimensions of these images were calculated using the box-counting method, respectively. They are all approximately equal to 1.4, although the distribution and the scale of wood fibres are extremely different. Then, a fractal model for predicting the effective thermal conductivities of wood was established using the thermal resistance method. In addition, we measured the effective thermal conductivity of wood via an improved transient plane source measurement method. The calculated results by the proposed model are in good agreement with the experimental data as well as the literature data. The comparison shows clearly that this fractal model can be used to accurately and effectively predict the effective thermal conductivities perpendicular to the fibres of wood.