Utilização do método lattice boltzmann no estudo da convecção natural em cavidade porosa heterogênea aquecida lateralmente

Abstract

In this work the phenomenon of natural convection in a heterogeneous square cavity filled with Newtonian fluid is numerically simulated. The solid domain is represented by thermally active square obstacles, uniformly distributed within the cavity. The mathematical model follows a continuum approach and the numerical solution of the problem is obtained using the Lattice Boltzmann method. The average Nusselt number evaluated at the heated surface, the streamlines and the isotherms show parametric results of the effect of varying the number of blocks ( N = 9,16,36,64,144 ), the porosity ( = 0,36;0,51;0,64;0,75;0,84 ), the solid-fluid thermal conductivity ratio ( k = 0,1;1;10;100 ) and the Rayleigh number ( Ra = 105 ,106 ,107 ) on the process of free convection inside the cavity. Aspects of the phenomenon of interference of the boundary layer are discussed and a methodology for observing this phenomenon is presented specifically focused on the hereby utilized method. Comparisons with results from the literature, attained by traditional numerical techniques, allow the evaluation of the innovative and alternative aspect of the Lattice Boltzmann method.