Measurement of laminar burning velocity of ethanol-air mixtures at elevated temperatures

The present work focuses on new measurement of laminar burning velocities of ethanol-air mixtures at 1 atm pressure and elevated mixture temperatures using an externally heated meso-scale diverging channel technique. The burning velocity measurements were carried out for a temperature range of 350-620 K and equivalence ratio range of 0.7-1.3. Various detailed kinetic models available in literature were used for assessment and comparison with experimental results. The experimental results show a good match at lower mixture temperatures across all equivalence ratios. However, at higher temperatures, the difference between the measurements and predictions of different kinetic models is considerably higher, particularly for rich mixture regime. The effect of mixture temperature on laminar burning velocity was assessed using power law correlation, S-u = S-u,S-0 (T-u/T-u,T-0)(alpha). The variation of temperature exponent, a with equivalence ratio, Phi showed a minimum value for slightly rich mixtures. This variation of the measured laminar burning velocity and temperature exponent at elevated mixture temperatures and predictions using various kinetic mechanisms shows a good match for lean mixtures.