Abstract
The influence of an acoustic field on premixed flame propagation was examined by numerical simulation and experiment. The influence was evaluated from the two points of view. One is the diffusive transport and the other is convective transport. The particle oscillation by sound is considered to increase diffusivity in the acoustic field like turbulent diffusion. The thermal convection occurs when the density difference exists in the acoustic field. It is considered that flame front is deformed by this thermal convection. To analyze the diffusive and convective influence of the acoustic field, experiment and numerical simulation with strong standing wave had been made. To evaluate the influence of the thermal convection, buoyancy-induced natural convection was removed. As the result, the effect of the thermal convection is clearly observed in both experiment and numerical simulation when the sound pressure level is above 150dB. And the numerical simulation results agreed with experimental results. The burning velocity changes in the acoustic field. The effect is significant especially for a flame that propagates perpendicular to the particle oscillation.
