Computational models of effective thermal conductivity for periodic porous media for all volume fractions and conductivity ratios

The effective thermal conductivity (ETC) of composites is of great significance for simulating the macroscopic heat transfer process. In this paper, an extension of the morphology efficiency is proposed, which quantifies the influence of morphology on composite ETC, and is initially derived from two extreme models-series and parallel ETC bounds. The morphology efficiency obtained from different bound models are compared. It concluded that the morphology efficiency derived from Hashin and Shtrikman bound models is the best representative of the morphology of isotropic composite materials, which can conveniently reveal the optimal volume fraction of inclusion phase and thermal conductivity of the ideal thermal response. For composites with inverse Simple Cubic, Body Centered Cubic, Face-Centered Cubic and Kelvin lattice, the corresponding prediction model of ETC is proposed in a wide range of porosity and thermal conductivity. Among them, the ETC model of Kelvin cell and inverse Simple Cubic cell can well predict the high porosity foam and foams filled with phases with thermal conductivity ratio r in the range of 3 to 8, respectively.