On the Interaction of a Premixed Flame with an Acoustic Disturbance

The main objective of this research is to analyze the effect of acoustic disturbances on a premixed flame and determine their role in the onset of combustion instabilities. Computations for the one-dimensional, unsteady combustion of a lean premixed methaneair mixture are performed. An acoustic excitation is introduced in the cha mber and interacts with the flame front. Our results indicate that as the amplitude of the acoustic excitation is increased, the flame front position fluctuates rapidly. This phenomenon is even more intense when the frequency of the acoustic disturbance ma tches the fundamental frequency of the chamber. Our results suggest that the interactions between the flame and the acoustic excitation may result in flame extinguishment. In addition various passive control devices are tested and we found that the Helmholtz resonator with rounded inlet corners is the most efficient.