The response of premixed flames to pressure oscillations

International audienceRecent measurements of the direct response of premixed flames to acoustic pressure fluctuations have shed doubt on the validity of analytical models that use irreversible one-step chemistry, and suggest that more realistic chemical kinetic models are needed to fully describe the unsteady dynamics of premixed flames. However, in the analysis of the experimental results some doubts subsisted concerning the exact relation between the intensity of emission from the excited OH* radical, used to determine the flame response, and the unsteady reaction rate given by the theoretical analyses. Combining experimental and numerical approaches on premixed methane-air flames, we propose corrections to give more confidence in the experimental results and to confirm the need for further investigations on the dynamics of unsteady premixed flames