A Modified Lattice Boltzmann Method for Predicting the Effective Thermal Conductivity of Randomly Open-Cell Foam Materials

The heat transfer in porous media have attracted wide attention in various scientific studies. The microstructure model of open-cell foam is reconstructed using the random generation method satisfying the microstructure stochastic properties. A modified Lattice Boltzmann method (LBM) is proposed to resolve the heat transport equations for predicting effective thermal conductivity (ETC). The proposed LBM simulation introduces the additional coefficient to moderate the difference in dimensionless relaxation time between solid and gas phase. The modified LBM simulation reliability is validated by comparing with numerical models and available experimental results. Simulations are conducted to evaluate the effects of a larger range of porosity, ambient pressure, temperature and intrusion mediums on heat transfer. The results indicate that the 400K is considered as a turning point in the ETC dependence on temperature. At low porosity, the ETC fluctuates more sharply compared to high porosity. The impact of ambient pressure on the ETC is divided into three levels: P 100kPa, the ETC significantly increases. The proposed LBM simulation combined with the random generation method is an efficient tool to predict the heat transfer for open-cell foam.