Numerical and Dynamic Study of Flow Instabilities and Heat Transfer at a Backward-Facing Step Using the Lattice Boltzmann Method

In this paper, a study of laminar flows based on lattice Boltzmann method (LBM) is presented. Numerical investigations of flow dynamics and its heat transfer at a backward-facing step were performed. We have considered an imposed temperature on system walls and chosen a convective exchange mode. The lattice Boltzmann method (LBM) was used to perform the modeling. This method is based on direct simulation at the macroscopic level of the fluid particle evolution. The influence of Reynolds number on the flow and on the temperature distribution was studied. The dynamic study of the structure of the flow at a backward-facing step allowed us to clarify its main characteristics: shear layer, mixed layer, recirculation, separation-reattachment, and the interaction between the mixture layer and the flow caused by the step. The results show the temperature oscillation distribution at a backward-facing step. This study will then give an initial appraisal of the influence of the atmosphere on airplane wings and plays a very important role in the interpretation of the pollutant dispersion mechanism at the urban scale.