A binary array method for calculating thermal conductivity of porous materials

作者:Xia Dehong*; Shen Liting; Ren Ling; Guo Shanshan
来源:Journal of Thermal Analysis and Calorimetry, 2014, 117(2): 825-829.
DOI:10.1007/s10973-014-3818-z

摘要

The present research on thermal conductivity of porous materials is hampered by their highly random internal structure. Until now, the researches could not describe internal structure of porous materials, but macro calculation expressions were established. In order to solve the above problem, this paper presents a method of calculation that applies a binary array. This method can describe the internal structure of porous materials, reflects its randomness, and calculates the thermal conductivity of porous materials. The technique selects large enough porous material models and divides them in small enough grids. Each grid needs a binary conversion process to determine if the grid is matrix or pore. Finally, a grid array composed of matrix and pore is established. Based on this grid array, this study sets the initial and boundary conditions, and then calculates the thermal conductivity of porous materials by a numerical calculation according to internal heat-transfer mechanism. This research adopts the described method to calculate the thermal conductivity of porous aluminum. The result is consistent with that of the experimental measurement, thereby verifying the accuracy and reliability of this method.