The effect of reflected acoustic disturbances on flame front acceleration

The frequency spectrum of acoustic disturbances that are emitted by accelerating flame front in an air–hydrogen mixture within an axially symmetric channel with a uniform cross section is experimentally determined. The effect of acoustic disturbances that are reflected from the closed end of the combustion chamber on the flame front acceleration is studied. It is revealed that the frequency spectrum of generated acoustic vibrations under experiment conditions has maximums at frequencies close to 250, 800, and 1500 Hz. The average flame velocity is 200 m/s. Spectra of generated acoustic vibrations and the flame front velocity depending on the material of the closed end of the axially symmetric channel are obtained for the stoichiometric air–hydrogen mixture.