Numerical Modelling of Porous Radiant Burners Using Full and Reduced Kinetics Mechanisms

The present paper compares full kinetics mechanisms in numerical modelling of porous radiant burners (PRB), with their reduced forms. The two most frequently used mechanisms of methane combustion (GRI3.0 and Miller) were selected and their effects were examined on temperature, species concentration, burning speed, and pollutant emission. While the findings of numerical simulation of PRB show fine concurrence between each full mechanism and its related reduced mechanism, no significant temperature differences are observed in the results of full mechanisms. However, CO concentration along burner axis shows a small difference between two full mechanisms, which is related to HCO and HO2 concentrations. The inconsistency is more pronounced for NO concentration along porous axis, which is due to prompt NO evaluation. The present research finds deviation also between burning speeds, calculated by numerical simulation and experimental results. This difference is much more significant in rich mixtures. GRI3.0 mechanism estimated the burning velocities as closer to the experimental values than those predicted using Miller mechanism.