The blow-off is one of the typical flame extinction mechanisms, and such a principle has been widely used in firefighting when the water-based extinguisher is limited. This work explores the blow-off extinctions of different diffusion flames by air vortex ring. The vortex ring harnesses its kinetic energy within the fast-rotating vortex core, enabling the transmission of power over several meters to blow off a remote flame. The power required for vortex ring blow-off is found to be two to three orders of magnitude smaller than the power of the flame itself, demonstrating exceptional energy efficiency. It is observed that the poloidal flow (circulation) surrounding the vortex core can stretch the flame base to the critical state and then cause instantaneous extinction. To explain the vortex-induced blow-off limit, a critical Damköhler number that accounts for the competition between fuel gas flow and flame stretch was formulated. This work provides a fundamental understanding of the extinction mechanism by vortex ring, and it offers technical guidelines for using air as a flame extinguisher for remote firefighting within minimum energy input.

吹灭是典型的灭火机制之一，这种原理在水基灭火器有限的消防中得到了广泛的应用。这项工作探讨了空气涡环对不同扩散火焰的吹灭。涡环利用快速旋转的涡核内的动能，将能量传输到几米之外，以吹灭远处的火焰。研究发现，涡环吹灭所需的功率比火焰本身的功率小两到三个数量级，这表明了卓越的能源效率。据观察，涡核周围的极向流（循环）可以将火焰底部拉伸至临界状态，然后导致瞬时熄灭。为了解释涡流引起的吹灭极限，制定了考虑燃气流量和火焰拉伸之间竞争的临界 Damköhler 数。这项工作提供了对涡环灭火机制的基本了解，并为在最小能量输入下使用空气作为火焰灭火器进行远程消防提供了技术指南。