Lattice Boltzmann Method Pore-scale simulation of fluid flow and heat transfer in porous media: Effect of size and arrangement of obstacles into a channel

Abstract

The flow characteristics at a pore-scale porous medium has a significant role to the development of cooling modules. Despite this fact, still there is no adequate knowledge about the effect of size, pattern and position of the obstacles, on fluid flow and heat transfer. In this work, fluid flow through the porous media and heat transfer have been modeled by means of the Single Relaxation Time SRT-LBM with BGK approximation and D2Q9 model. The effect of size and arrangement of cold square obstacles in a heated wall channel is investigated for incompressible flow in case of fixed porosity degree, ε=75%. Results are presented in terms of velocity and temperature fields, streamlines, and Nusselt number. The results show that, for the same porosity degree, by changing the number of the obstacles or their arrangement, the tortuosity changes and therefore velocity and temperature fields are modified, as well as local and average Nusselt number. The results show that, for the same porosity degree, by changing the number of the obstacles or their arrangements, the value of Nuavg of the channel walls and tortuosity increased up to 24.7% and 9%, respectively, in comparison with the Poiseuille flow.