Application of acoustic oscillations in flame extinction in a presence of obstacle

Abstract

Currently, a grooving body of research devoted to the potential use of acoustic waves in suppression of different flame types can be observed. However, all works related to this issue focus on flame quenching in open environment or inside resonator tube. When concerning the use of acoustic waves in a fire/flame extinction, one may expect that the closest environment of a flame would not be free of obstacles. Thus, the present work investigates experimentally how the acoustic screen - being the simplest model of a single obstacle affects the quenching process. To do so, the sound levels required to extinguish a gas burner flame were determined for both different distances between an acoustic screen and a waveguide outlet and different fuel loads. It was found that when decreasing distance between the acoustic screen and the waveguide outlet a higher sound levels are required to suppress the flame - what is quite surprising as the sound level alone also increases when the screen approaches the waveguide outlet. The physical interpretation of this feature formulated based on the present and earlier researches is also included in the present paper.