Length-Scales of Wrinkling of Weakly-Forced, Unstable Premixed Flames
Length-Scales of Wrinkling of Weakly-Forced, Unstable Premixed Flames
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弱受力不稳定预混火焰起皱的长度尺度
DOI：
10.1080/00102209408935388
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发表时间：
1994
影响因子：
1.9
通讯作者：
J. Guy
中科院分区：
文献类型：
--
作者：
C.St. Pierre;J. Guy
在包含Landau-Darrieus不稳定性机制和曲率效应的非线性模型框架中，我们研究了受到已知r.m.s，强度（~µ'）和长度尺度（~ Lint）的入射速度波动的薄预混火焰。具体而言，我们对具有周期性边界条件的Michelson-Sivashinsky型强迫演化方程进行了数值积分，并重点关注了前波峰之间的平均间距'erul(t)。强迫模拟了中等各向同性湍流的单分量、近洛伦兹谱；阶段和周转时间是随机抽样的。处理多次运行的结果表明：i)在长时间极限/(:resl在值Ll附近波动；否则，一旦集合平均得到数量1/'，仅微弱地依赖于横向火焰程度（如果后者足够大）；相反，AcreI，主要尺度像边缘稳定的波长中性的线性化。非强迫进化方程。ii)行动起来吧，如果你是……
In the framework of a nonlinear model which incorporales the Landau-Darrieus instability mechanism and curvature effects, we study thin premixed flames subjected to incoming velocity fluctuations of known r.m.s, intensity (∼ µ') and length-scale ( ∼ Lint). Specifically, we numerically integrate a forced evolution equation of Michelson-Sivashinsky type, with periodic boundary conditions and focus attention on the mean spacing 'erul(t)between front crests. The forcing mimics the one-component, near Lorentzian spectrum of moderate, isotropic turbulence; the phases and turnover times are randomly sampled. Processing the results of many runs suggests that: i) in the long-time limit /(:resl fluctuates around a value Ll;lest which, once ensemble-averaged to give the quantity 1/' only feebly depends on the lateral flame extent (if the latter is large enough); instead, AcreI, mainly scales like the marginally-stable wavelength Aneutral of the linearized. unforced evolution equation. ii) oActnJou' 0 and, if u'/SL i...