Dynamic characteristics and response mechanism of pool fire under external acoustic excitation

Liquid fuel is an important raw material in the energy industry, and liquid pool fires pose a huge threat to related industrial processes and safety. The response characteristics and fire extinguishing dynamics mechanism of pool fires under the action of acoustic excitation as a potential fire extinguishing technology have been studied. Based on a self-built experimental system, the dynamic characteristic parameters are studied, and the flame shape evolution and fuel mass loss characteristics under acoustic excitation are analyzed. Further, the critical characteristics and mechanisms of flame extinction induced by acoustic excitation have been identified. The results indicate that under the excitation of the acoustic source, acoustic waves attenuate with increasing distance in the direction of action. The decrease in acoustic frequency and the increase in pressure result in an increase in the displacement of the diaphragm, and a correlation model between the three has been constructed. Moreover, as the intensity of acoustic excitation increases, the flame shape shrinks, expands, and finally disappears frequently. Correspondingly, the lateral deflection of the flame becomes more severe. The fuel mass loss rate is monotonically positively correlated with acoustic pressure. With the increased acoustic frequency, the critical pressure of different fire sources for extinguishing increases linearly, while the crucial displacement for flame extinguishing remains constant.