We have recently shown that premixed ${\text{CH}}_4$/air flames anchored behind flame holders can stabilize in two flame stabilization regimes characterised by the presence or absence of a recirculation vortex [1]. Focus of the present work is on the underlying mechanisms governing flames anchored without the presence of a vortex for methane-air flames. We revisit the definition of the flame anchoring location and define a new anchoring location which results from flame stretch considerations rather than heat loss considerations. This location can be unambiguously defined for flame holders of different sizes. It is argued that such an anchoring location is more relevant for flames stabilized behind flame holders with sharp corners and do take into account the multi-dimensional nature of heat transfer with the flame holder as well. A quantitative assessment of heat transfer, stretch and preferential diffusion effects is then carried out at the anchoring location for elucidating their impact on the flame speed as a function of the flame holder size. New insights into flame blow-off, flashback and emergence of a recirculation vortex are obtained as a result of this investigation.

我们最近表明，预混 ${\text{CH}}_4$固定在火焰保持器后面的 / 空气火焰可以稳定在两种火焰稳定状态中，特征是存在或不存在再循环涡流 [1]。当前工作的重点是在没有甲烷空气火焰涡流存在的情况下控制火焰的潜在机制。我们重新审视了火焰锚定位置的定义，并定义了一个新的锚定位置，该位置由火焰拉伸考虑而不是热损失考虑产生。可以为不同尺寸的火焰保持器明确定义该位置。有人认为，这样的锚定位置与在带有尖角的火焰保持器后面稳定的火焰更相关，并且确实考虑了与火焰保持器的热传递的多维性质。传热的定量评估，然后在锚定位置进行拉伸和优先扩散效应，以阐明它们对火焰速度的影响，作为火焰保持器尺寸的函数。作为这项调查的结果，获得了对火焰吹散、回火和再循环涡流出现的新见解。