Radiation Heat Flux of the Gas Burner using Open-cellular Porous Media
Abstract
Abstract
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Radiation heat flux from the combustion of the methane-air premixed gas on???????????????????????????????????????? an open-cellular porous burner was investigated experimentally and numerically. In the experiment, an alumina-cordierite (Al-Co) having pores per inch (PPI) of 13 and porosity (f) of 0.872 was examined. Radiant output from the porous burner was measured based on a two-color radiometry. For the analysis, we assumed that the chemical kinetics of gas-phase (energy equation) reactions was governed by a single-step Arrhenius rate expression. 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 the P1 approximate method. The stable combustion of the present burner was characterized by flash-back limits, where the equivalence ratio (F) was around 0.48 to 0.5, and blow-off limits???????????? (F was around 0.62 to 0.76). The radiant outputs depended on F and Reynolds number (Re). Predicted results of the dimensionless forward radiative heat flux (Y+) and the burner surface temperature (TS) were reasonably 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.
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Keywords: Radiation heat flux, Porous burner, Premixed gas, Open-cellular porous material