Simulação numérica da convecção natural em cavidades porosas aquecidas lateralmente utilizando o método lattice boltzmann

Abstract

In this work, the transport phenomenon of heat transfer through natural convection in a square cavity heated from the side is filled with saturate fluid and a homogeneous porous medium investigated, using the Lattice Boltzmann Method. Results are presented for the variation of the Rayleigh number (Ra = 103 – 107), the Darcy number (Da = 10-2 – 10-6) and the internal porosity of the cavity (  =0,4 – 0,9). The heat transfer through the medium is evaluated by the average Nusselt number on the cavity, and by the isothermals and streamlines. Inceasing the Rayleigh number an intensification on the recirculation of fluid inside the cavity can be observed, and, consequently, an increase on the heat transfer. Likewise, the increase of the Darcy number enhances the whole recirculation inside the cavity as it represents an increase on the cavity's permeability. The variation on the porosity of the cavity presents a lower influence when compared to the other parameters. A correlation was proposed to predict the average Nusselt number in the cavity as a function of these parameters.Trough the comparison to benchmark results, it is possible us to evaluate the inovative character of the Lattice Boltzmann Method.