An improved thermal lattice Boltzmann model for rarefied gas flows in wide range of Knudsen number

In order to covering a wide range of the flow regimes, a new relaxation time formulation for the lattice Boltzmann method, LBM, by considering the rarefaction effect on the viscosity and thermal conductivity has been presented. To validate the presented model, fully developed pressure driven flow and developing thermal flow in micro/nano channel have been modeled. The results show that in spite of the standard LBM, the velocity and temperature distributions, the volumetric flow rate and the local Nusselt number obtained from this modified thermal LBM, agree well with the other numerical and empirical results in a wide range of Knudsen numbers.