Computation of heat transfer and fluid flow in an obstructed channel using lattice Boltzmann method

摘要

Purpose - The purpose of this paper is to investigate the laminar flow and heat transfer characteristics in a two-dimensional horizontal channel with two square blocks placed side-by-side using a numerical scheme based on a coupling between the lattice Boltzmann method and the finite difference method.rnDesign/methodology/approach - The multiple-relaxation-time (MRT) lattice Boltzmann equation model coupled with the finite difference method are used to predict numerically the velocity and the temperature fields.rnFindings - A complex structure of the fluid flow was observed for various dimensionless block separation distance (G). An unsteady flow was found when the two blocks are placed side by side (G = 0). For G < 1.5, the presence of each block develops the street of Van Karman which generates complex binary vortex street. In the opposite case (G > 1.5), the effect of this parameter (G) on the fluid is reduced, whereas, the distance between the blocks and the nearest walls have a great influence on the fluid flow and the heat transfer. When the obstacles are posed on the walls (G = 3), an important heat exchange between the blocks and the nearest walls is noted. Originality/value - This study offers more knowledge on natural convection in an obstructed channel. Furthermore, this work shows the effectiveness of the MRT lattice Boltzmann equation model for this kind of geometry.