Abstract Dripping of molten fuels is a widely observed phenomenon in the wire fire and facade fire, which promotes the fire spread and increases the fire hazard. The flame attachment to drip is a necessary condition for dripping ignition, so that extinguishing the dripping flame can effectively reduce the dripping fire hazard. In this work, we investigated the use of acoustic wave to extinguish the fast-moving dripping flame. Continuous drips, with a mass of 6.2 mg and a diameter of 2.6 mm, were produced from a burning polyethylene tube, and two fall heights, 0.3 m and 0.7 m with velocities of about 2 m/s and 3 m/s, were selected as the targets. The sound source varied in pressure from 80 to 114 dB and frequency from 90 to 110 Hz. Results showed that the effectiveness of flame extinction by acoustic wave decreases as the dripping velocity increases, so the acoustic wave is more effective to extinguish the dripping flame in the early stage. An extinction criterion was formulated based on a characterized Damkohler number to describe the underlying mechanism. This work provides important information on the acoustic effect on a moving flame and helps mitigate the fire hazard of dripping phenomena.

中文翻译：

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用声波扑灭滴落的火焰

摘要 熔融燃料滴落是电线电缆火灾和立面火灾中普遍存在的现象，它促进了火势蔓延，增加了火灾隐患。火焰附着滴液是滴液点火的必要条件，扑灭滴液火焰可以有效降低滴液着火的危险。在这项工作中，我们研究了使用声波来扑灭快速移动的滴落火焰。由燃烧的聚乙烯管制成质量为 6.2 mg、直径为 2.6 mm 的连续滴液，并选择了速度分别为 2 m/s 和 3 m/s 的 0.3 m 和 0.7 m 两个坠落高度作为目标。声源的压力范围为 80 至 114 dB，频率范围为 90 至 110 Hz。结果表明，随着滴落速度的增加，声波熄灭火焰的有效性降低，因此声波在早期熄灭滴落火焰更有效。基于表征的 Damkohler 数制定了消光标准来描述潜在的机制。这项工作提供了关于移动火焰的声学效应的重要信息，并有助于减轻滴落现象的火灾危险。