Indoor Air Quality Analysis of a Ventilated Chamber Separated by a Porous Matrix: Lattice Boltzmann Simulations

Abstract

This study aims to reduce energy consumption and optimize indoor air quality in thermally conditioned buildings through a numerical analysis of air quality in a rectangular chamber ventilated by air displacement. The lattice Boltzmann multiple relaxation time (LBM-MRT) method was employed to simulate the physical behavior of a rectangular room with heating applied to its left vertical wall. A porous partition was introduced at the center of the floor. The extended Darcy–Brinkman–Forchheimer model was applied to model the porous medium. Computational simulations were conducted over a range of characteristic numbers. The results indicate that optimal thermal dissipation conditions in a ventilated cavity with a porous separator are achieved at moderate Reynolds numbers (∼250) and high Rayleigh numbers (∼106). Thermal comfort is realized when natural convection dominates the flow dynamics. Moreover, in a porous medium with low permeability (∼10−6), natural convection leads to a pollutant displacement efficiency twice that of forced convection, irrespective of the buoyancy ratio. These findings underscore the significance of integrating ventilation systems with porous materials to achieve energy-efficient indoor environments.