Abstract Unsteady flame propagation within a narrow channel, namely a Hele-Shaw burner, exhibits complicated phenomena. Recently, a new narrow-gap-disk-burner (NGDB) was developed, of which the disk-gap could be varied continuously and precisely. Although various complicated flame structures have been observed successfully, their dependency on the initial ignition has not been clarified. In this study, the volume of the ignition part was varied to introduce disturbance at the ignition stage, and the propagation characteristics of premixed methane and propane flames were investigated. Conclusively, quenching distance was not significantly affected by the ignition volume, especially in propane-rich conditions. In contrast, the flame structure and propagation velocity were sensitive to the ignition volume if it was larger than a critical volume, and when the disk-gap was approximately 1.5 times the quenching distance. A strong initial disturbance could generate complicated cellular structures coupled not only with shear stress but also with heat transfer. These cellular structures could increase the flame propagation velocity when the Lewis number was sufficiently smaller than unity. In contrast, the flame shape became smoother when the disk-gap was sufficiently larger than the quenching distance. Thus, the flame propagation velocity was comparable to the laminar burning velocity when it was less affected by the initial disturbance.

中文翻译：

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点火扰动对窄间隙圆盘燃烧器中甲烷和丙烷火焰传播的影响

摘要 Hele-Shaw 燃烧器在狭窄通道内的非稳态火焰传播表现出复杂的现象。最近，开发了一种新的窄间隙磁盘刻录机（NGDB），其磁盘间隙可以连续精确地变化。尽管已成功观察到各种复杂的火焰结构，但它们对初始点火的依赖性尚未阐明。本研究通过改变点火部分的体积在​​点火阶段引入扰动，研究了预混甲烷和丙烷火焰的传播特性。结论是，熄火距离不受点火体积的显着影响，尤其是在富含丙烷的条件下。相反，如果点火体积大于临界体积，火焰结构和传播速度对点火体积敏感，当盘间隙大约是淬火距离的 1.5 倍时。强烈的初始扰动会产生复杂的细胞结构，不仅与剪切应力有关，而且与传热有关。当刘易斯数足够小于 1 时，这些蜂窝结构可以增加火焰传播速度。相反，当圆盘间隙比淬火距离足够大时，火焰形状变得更平滑。因此，当受初始扰动的影响较小时，火焰传播速度与层流燃烧速度相当。当刘易斯数足够小于 1 时，这些蜂窝结构可以增加火焰传播速度。相反，当圆盘间隙比淬火距离足够大时，火焰形状变得更平滑。因此，当受初始扰动的影响较小时，火焰传播速度与层流燃烧速度相当。当刘易斯数足够小于 1 时，这些蜂窝结构可以增加火焰传播速度。相反，当圆盘间隙比淬火距离足够大时，火焰形状变得更平滑。因此，当受初始扰动的影响较小时，火焰传播速度与层流燃烧速度相当。