Comparison of experiments and a nonlinear model equation for spatially developing flame instability
Comparison of experiments and a nonlinear model equation for spatially developing flame instability
复制标题
空间发展火焰不稳定性的实验与非线性模型方程的比较
DOI：
10.1063/1.1407815
复制
发表时间：
2001
影响因子：
4.6
通讯作者：
G. Joulin
中科院分区：
文献类型：
--
作者：
G. Searby;Jean;G. Joulin
我们扩展的迈克尔逊-Sivashinsky方程，任意气体密度比，模拟倾斜锚定火焰前锋的动态。切向于火焰前缘的流速分量将时间上发展的结构转变为空间上发展的结构。进一步的研究表明，对于有限的流速，应该发生从绝对不稳定到对流不稳定的转变。利用极点分解，我们给出了一个特殊的解决方案，这个方程的限制高流速相比，层流火焰速度。分析结果进行了比较，一个二维层流火焰的测量。饱和结构的生长速率、形状和振幅以及交叉区域的宽度都得到了很好的描述。然而，我们实验观察到的大规模横向气体循环的存在下，没有预测的分析。我们把这种效应归因于火焰刷上压力跃变的流向变化。
We extend the Michelson–Sivashinsky equation, for arbitrary gas density ratio, to model the dynamics of an inclined anchored flame front. A flow velocity component tangential to the flame front transforms temporally developing structures into spatially developing ones. Closer investigation shows that a transition from absolute to convective instability should occur for a finite flow velocity. Using pole decomposition, we give a particular solution to this equation in the limit of high flow velocity compared to laminar flame speed. The analytical results are compared to measurements on a two-dimensional laminar flame. The growth rate, shape, and amplitude of the saturated structures, as well as the width of the crossover region are all well described. However, we experimentally observe the presence of a large scale transverse gas circulation not predicted by the analysis. We attribute this effect to the streamwise variation of the pressure jump across the flame brush.