The thick flame asymptotic limit and Damköhler's hypothesis
The thick flame asymptotic limit and Damköhler's hypothesis
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浓火焰渐近极限和 Damköhler 假设
DOI：
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发表时间：
2002
期刊：
影响因子：
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通讯作者：
M. Matalon
中科院分区：
文献类型：
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作者：
J. Daou;J. Dold;M. Matalon
我们推导出火焰在规定的稳定平行流中传播的燃烧速率的解析表达式，该平行流的尺度远小于层流火焰的厚度，在这种特定的情况下，渐近结果可以被看作是Damköhler的假设的分析测试，该假设与流动中的小尺度对火焰的影响有关;描述了有效扩散过程的增加。结果不限于绝热等扩散的情况下，这是第一次处理，但地址也非单位刘易斯数和体积热损失的影响。特别是，它表明，非单位刘易斯numbereffects变得微不足道的渐近极限考虑。它还表明，有效的传播速度对流量的依赖性是相同的绝热等扩散的情况下，提供它是缩放的平面非绝热火焰的速度。
We derive analytical expressions for the burning rate of a flame propagating in a prescribed steady parallel flow whose scale is much smaller than the laminar flame thickness.In this specific context, the asymptotic results can be viewed as an analytical test of Damköhler's hypothesis relating to the influence of the small scales in the flow on the flame; the increase in the effective diffusion processes is described. The results are not restricted to the adiabaticequidiffusional case, which is treated first, but address also the influence of non-unit Lewis numbers and volumetric heat losses. In particular, it is shown that non-unit Lewis numbereffects become insignificant in the asymptotic limit considered. It is also shown that the dependence of the effective propagation speed on the flow is the same as in the adiabatic equidiffusional case, provided it is scaled with the speed of the planar non-adiabatic flame.