A multi-block lattice Boltzmann method for the thermal contact resistance at the interface of two solids

In the present paper, a patching type multi-block lattice Boltzmann method is adopted to predict the thermal contact resistance (TCR) at the interface of two solids. The rough surfaces of contact materials are reconstructed based on the fractal theory and the contact pressure is obtained based on the plastic deformation model. The accuracy of the patching type multi-block lattice Boltzmann method is validated by some benchmarks. After validations, effects of the contact pressure, roughness, thermal conductivity of contact material, thermal conductivity of interstitial medium, temperature and radiation on TCR are investigated. The results show that: the TCR decreases when the contact pressure increases, but increases with the root-mean-square roughness; the TCR of two contact aluminums decreases faster than that of stainless steels when contact pressure increases; a higher thermal conductivity of contact materials leads to a smaller TCR; when the thermal conductivity of interstitial medium is close to zero or the gap is in vacuum, the TCR is much larger than that filled with air, especially at low contact pressure; at the high temperature, the contribution of the radiation to the TCR becomes appreciable if the thermal conductivity of the interstitial medium is low. Especially when the gap is in vacuum, the contribution of radiation on the TCR cannot be neglected.