STABILITY OF A LAMINAR JET DIFFUSION FLAME OF METHANE IN AN OXYGEN ENRICHED AIR CO-JET

Abstract The effect of adding oxygen in the combustion of a laminar flame methane/air is studied. The volume content of oxygen obtained varies between 21% (air) and 30%. The results relate to the heights of dropping flame based on initial rates of CH 4 , air and oxygen percentages. Stability diagrams showing the states of the flame and transitions between these states are built. The reduction drop observed during the addition of oxygen is explained by the increase in laminar flame speed and increased heat release due to a higher flame temperature. Keywords: laminar diffusion flame -lifted flame -oxygen enriched air -flame stability. Introduction Oxygen is the component of air which plays the dominant role in the combustion reactions. Many studies have been conducted on flames in air enriched with oxygen and several objectives are aimed: increasing the flame temperature and thus improving energy efficiency, reducing fuel consumption, increasing the concentration of CO 2 emissions and reducing emissions of nitrogen oxides. Previous studies have been conducted to examine the effect of this enrichment on flame characteristics: laminar speed boundary extinction, frequency and amplitude of oscillations and vortices instabilities. The effect on the frequency and amplitude of oscillations of the top of the flame was studied by Gotoda et al