Three-dimensional pore-scale simulation of non-equilibrium in a two-layer porous burner

Abstract

A pore-scale numerical simulation for combustion of methane-air mixtures in a two-layer porous media burner made of staggered arrangement of connected particles is preformed. Combustion is modeled by a one-step reaction mechanism, and solid surface radiation heat transfer is computed by discrete ordinates (DO) model. The bridge approach is used to deal with the point contact between adjacent particles. The present study is intended to investigate the non-equilibrium characteristics of gas velocity and temperature under two operating parameters such as the inlet velocity and equivalence ratio. A comparison of the numerical values and experimental values was carried out to prove the effectiveness of numerical model, and a good agreement is shown. The results showed considerable non-equilibrium of velocity and temperature along the space coordinate due to the inhomogeneous porous structure. The extent of flow non-equilibrium increases as inlet velocity and equivalence ratio are increased. The extent of gas temperature non-equilibrium decreases slightly with the inlet velocity, but the equivalence ratio effect on thermal non-equilibrium can be neglected.