Laminar burning velocity of acetic acid + air flames

Laminar burning velocities of acetic acid + air flames at 1 atm and initial gas temperatures of 338 K, 348 K, and 358 K were determined using the heat flux method. Measurements were performed in non-stretched flames, stabilized on a perforated plate burner at adiabatic conditions. Due to experimental problems related to the corrosiveness of acetic acid towards the burner material, the uncertainty of the burning velocities was relatively high up to ± 2 cm/s. Seventy reactions pertinent to acetic acid and ketene have been reviewed and detailed reaction mechanism for acetic acid combustion was developed. The model over-predicts measured burning velocities by about 3 cm/s. The mechanism was also tested comparing with flame structure of the low-pressure flame of acetic acid (Leplat and Vandooren, 2012). Good agreement with the concentration profiles of major products was found, however several minor intermediates were over- or under-predicted by the model. To elucidate reactions responsible for the differences observed, the sensitivity analysis was performed. It was found that the calculated burning velocities are insensitive to the reactions of acetic acid and mostly governed by C1 chemistry typical for all hydrocarbons and by reactions of ketene. Possible modifications of the rate constants within the evaluated uncertainty factors were discussed.