Radiation Emission Characteristics of an Open-Cellular Porous Burner

Abstract

Radiation emission characteristics of an open-cellular porous burner, where methane-air premixed combustion occurs, were investigated experimentally and theoretically. In the analysis, we assumed that the chemical kinetics of gas-phase reactions are governed by a single-step Arrhenius rate expression. The energy liberation due to combustion and the effects of radiation were considered in the energy equations for the gas and solid phases. To evaluate the radiative transports in the solid-phase energy equation, the equation of transfer for the radiation field in a porous burner was solved using Barkstrom' s finite difference method and the P1 approximation. Three kinds of Ni-Cr open-cellular porous material with different porosities and pores per inch (PPI) were examined. Radiant output from the porous burner was measured based on a two-color radiometry. Calculated results of the forward radiative heat flux and the burner surface temperature were favorably compared with experimental data: satisfactory agreement between theory and experiment was obtained, and thereby the validity of the present theoretical model for predicting the radiation from a porous burner was confirmed. Moreover, it is found that there is only a little difference between predicted results of Barkstrom' s method and these of the P1 approximation.

Keywords

• radiation emission characteristics
• porous burner
• open-cellular porous material
• premixed combustion