预混火焰在冷壁面狭缝中传播与熄灭的判据

模拟了非稳态预混乙炔-空气火焰在冷壁面平板狭缝中的传播与熄灭，针对壁面散热和狭缝高度对火焰形状和火焰传播状态的影响进行了重点讨论，结果显示，火焰在较大的狭缝通道中会经历一个由郁金香状向蘑菇状转变的过程，即壁面散热抑制了郁金香状火焰的形成，较小狭缝通道中的火焰初始时刻会形成蘑菇状火焰，但随着散热的加强，火焰会逐渐熄灭，另外，系统分析了火焰在不同高度狭缝中的传播与熄灭状态，提出了火焰部分熄灭和完全熄灭的判定标准，即火焰在平板狭缝中传播与熄灭的判据。

Criterion of Propagation and Quenching of Premixed Flames in Cold Walled Narrow Channels

The propagation and quenching of unsteady premixed flames in narrow channels with cold walls are numerically investigated. It is assumed that the flame chemistry is modeled by one-step overall reaction which simulates the reaction of a stoichiometric acetylene-air mixture. The numerical results show that, a transition from tulip-shaped flame to mushroomshaped flame occurs in larger sized narrow channels as flames propagate from one end of the channel to the other. While in smaller-sized narrow channels, a mushroom-shaped flame forms at the beginning of flame propagation, and then the flames quench gradually. In addition, flame propagation and quenching in different-height narrow channels are analyzed systematically, and a criterion is put forward to judge the flame states of partial quenching or total quenching. It is called propagation and quenching criterion of flame in narrow channels.