A thermal LBM model for studying complex flow and heat transfer problems in body-fitted coordinates

Abstract

A thermal lattice Boltzmann model in a body-fitted coordinate system has been proposed by combining the thermal lattice Boltzmann model on uniform grids with the generalized form of interpolation-supplemented lattice Boltzmann method (GILBM), and then it is validated by numerically simulating flow and heat transfer problems in domains with irregular geometry. The flow around a circular cylinder has been investigated under different Reynolds numbers. Both pressure coefficients and Nusselt numbers around cylindrical surface are in good agreement with previous numerical and experimental results. The natural convection in horizontal concentric and eccentric cylindrical annuluses has also been studied, respectively. It is found out that equivalent heat conductivity increases gradually as Rayleigh number. What's more, the equivalent heat conductivities on the inner and outer cylindrical surfaces are consistent with the experimental results with acceptable deviations. These comparisons show that the proposed thermal lattice Boltzmann model is feasible and reliable to simulate fluid flow and heat transfer problems in domains with irregular geometry.