Estimation of effective thermal conductivity in open-cell foam with hierarchical pore structure using lattice Boltzmann method

Abstract

• Hierarchical pore structure is built in open-cell foam by an artificial algorithm. • Effective thermal conductivity (ETC) was calculated by lattice Boltzmann method. • Effects of hierarchical pore structure on ETC were investigated. • ETC correlation for open-cell foam with hierarchical pore structure is derived. Effective thermal conductivity in open-cell foam with hierarchical pore structure was estimated using lattice Boltzmann method. A new structure algorithm was proposed to reconstruct hierarchical pore structure in open-cell foam. In order to elucidate the heat transfer characteristics in hierarchical pore structure, the effect of structure parameters, namely the hierarchical pore size ratio ( d 2 / d 1 ), the hierarchical pore volume ratio ( V 2 / V 1 ), and temperature on the effective thermal conductivity was investigated. These results indicated that hierarchical pore structure is unfavorable to the effective thermal conductivity in open-cell foam for the heat conduction process. At high temperatures ( T ave =450-1650 K ), however, the effective thermal conductivity in hierarchical pore structure is higher than that in uniform pore structure considering heat radiation. Furthermore, for the heat conduction process, a correlation of the effective thermal conductivity related to open-cell foam with hierarchical pore structure was proposed and validated by available experimental data.