Numerical and experimental investigation of matrix-stabilized methane/air combustion in porous inert media

Porous media combustion offers exceptional advantages compared with techniques involving free flame burners. Porous medium burners are characterized by higher burning rates, increased flame stability, and lower combustion zone temperatures, which lead to a reduction in NO, formation. In addition, they show a very high turndown ratio, low emissions of CO, and are of very small size. In order to optimize the combustion process further and to adapt the burner design, as well as to obtain a tool that allows fast adaptation to new industrial applications, a numerical code utilizing a pseudohomogeneous heat transfer and flow model for the porous material was applied. It considers conservation equations for 20 species, two momentum equations, and one energy equation. This model enabled a numerical parametric study to be made for a porous medium burner with a rectangular cross-section geometry. The calculated 2D temperature fields and species concentrations, with premixed methane/air combustion, are compared with data obtained from experiments with the same burner geometry. It is shown that there is good agreement between the numerical solutions and the experimental data and it is concluded that the developed numerical program is an excellent tool to investigate combustion in porous media. (C) 2000 by The Combustion Institute.