Numerical study of obstacles effect on natural convection inside square cavity: Lattice Boltzmann method

In this work, we are focused on numerical simulation by lattice Boltzmann method. The natural convection is studied in a closed square cavity differentially heated. The latter is managed by two rigid walls in right and left sides. The cavity is completely filled with a Newtonian fluid. It is provided with two rectangular adiabatic obstacles interposed on the horizontal walls. The height of the two obstacles is varied from 10% to 40% of the side (H), while the width remains constant and equal to 10% of (H). The calculation code was performed for a laminar flow and an incompressible fluid with a Prandtl number Pr = 0.71 (the case of air). The computation code thus developed was used to analyse the effect of the length of fins in mid square cavity. The obtained results were validated by comparing with those of a previously published work and with those obtained using COMSOL Multiphysics. It has been deduced that the addition of the obstacles influences the thermal and hydrodynamic profiles of the flow inside the cavity and its thermal performances.