The unsteady investigation of methane-air premixed counterflow flame into newly proposed plus-shaped channel over palladium catalyst

Abstract

In this paper, the time dependent study of methane-air premixed counterflow flame into a newly proposed plus-shaped channel, in order to obtain effects of palladium catalyst surfaces on the flame structure and pollutant emissions, is described. The results are presented at non-catalytic and catalytic conditions with considering effects of reaction time and various equivalence ratios, from lean to rich combustion, on flame characteristics and pollutant emissions. The governing equations are composed of continuity, momentum, energy and mass fraction equations are numerically solved considering a coupled Piso scheme and Simple algorithm. The comparison between the presented model and published data shows an acceptable agreement that confirms the accuracy of response. The average values of CH4 mass fraction over the geometry at the presence of palladium catalyst is nearly decreased 25% relative to non-catalytic case. The existence of Palladium catalyst has great impact, mostly 34% decrease, on CO formation but the catalyst leads to increment of CO2 formation 5%. At different values of equivalence ratio, the average temperature of non-catalytic flame is about 16% lower than catalytic one.