Mesoscopic pore-scale simulations of natural convection of porous media in closed square cavity by using LBM

摘要

A lattice Boltzmann model is applied to simulate natural convection of porous media in closed square cavity. The numerical simulation is conducted to investigate the influences of porosity on fluid flows and the effect of thermal conductivity ratio of solid matrix to fluid on heat transfer. Micro X-CT has been used to obtain 2D optical image of various slice with different location. A construction porous model has been established accurately by 2D optical micro X-CT image of porous media. A fluid - solid conjugate heat transfer model has been applied to the established construction porous model by using Lattice Boltzmann method.This paper confirms the reliability and the computational efficiency of the lattice Boltzmann method in simulating natural convection in porous media at mesoscopic pore-scale.The temperature field is simulated by a simplified thermal energy distribution function which neglects the compression work done by the pressure and the viscous heat dissipation. A comprehensive parametric study of natural convective flows is carried out for various values of Rayleigh number.