Simulation of a cavity ventilated by air displacement using the lattice boltzmann method

Abstract

This work consists in numerically simulating a double diffusive mixed convection in a cavity ventilated by two diagonally opposed openings in the presence of a porous partition, fixed in the middle of its base and modeled by the Darcy-Brinkman-Forchheimer model. The right-side wall is brought to a constant warm temperature while the other walls are kept adiabatic. The Lattice Boltzmann method with a multiple relaxation time (MRT) is used for the mathematical resolution. The results are illustrated in terms of streamlines, isotherms and isoconcentrations as a function of different control parameters (Reynolds number, Rayleigh number) for a Darcy value Da = 10 - 6 and a height of the porous partition Hp = 0.6. The influence of these parameters on the depollution efficiency was also studied. It has been concluded that the optimal pollution efficiency is obtained at maximum Reynolds values related to the incoming air flow. Also, it was possible to approve the efficiency of the model proposed in this study to evacuate the maximum of heat and pollutants to decrease the ambient temperature as well as the concentration of pollutants. This study aims to provide guidelines to the building constructors in order to obtain a better air quality and ensure a good thermal comfort to the occupants