Measurement of adiabatic burning velocity in natural gas-like mixtures

Experimental measurements of the adiabatic burning velocities were carried out for natural gas-like mixtures burning in air over a range of equivalence ratios at atmospheric pressure. Effect of CO2 dilution up to 60%, N2 dilution up to 40% and 25% enrichment of ethane on burning velocity of methane–air flames were studied. Heat flux method with setup similar to that of [K.J. Bosschaart, L.P.H. de Goey, Detailed analysis of the heat flux method for measuring burning velocity, Combustion and Flame 132 (2003) 170–180] was used for measurement of burning velocities. Initially experiments were done for methane–air and ethane–air mixtures at various equivalence ratios and the results were in good agreement with published data in the literature. Computations were performed using PREMIX code with GRI 3.0 reaction mechanism for all the mixtures. Predicted flame structures were used to the explain the effect of N2 and CO2 dilution on burning velocity of methane–air flames. Peak burning velocity for CH4/CO2–air mixtures occur near to ϕ = 1.0.