A Lattice Monte Carlo analysis of the effective thermal conductivity of closed-cell aluminum foams and an experimental verification

A Lattice Monte Carlo (LMC) method was employed to predict the effective thermal conductivity (ETC) of closed-cell aluminum foams with porosities between 0.828 and 0.894 through a cubic unit model. The numerical results demonstrated a linear dependency on the relative density when the cell wall thermal conductivity (CWTC) was set as that of pure aluminum; the dependency had large deviations from the measured ETCs obtained via a steady-state comparative method. To characterize the actual CWTC, its relationship with the ETC was deduced, and its value was determined through the measured ETC. On the other hand, the cubic unit model was improved with consideration of the plateau borders characterized through Image-Pro software. With the corrected CWTC and the improved cubic unit model, the numerical results agreed well with the measured results. Hence, the LMC method can be used to predict the ETC of closed-cell aluminum foams accurately through a cubic unit model, provided that the relative density, the CWTC and the plateau borders are taken into account.