Diffusive-thermal instabilities of a planar premixed flame aligned with a shear flow
Diffusive-thermal instabilities of a planar premixed flame aligned with a shear flow
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与剪切流对齐的平面预混火焰的扩散热不稳定性
DOI：
10.1080/13647830.2023.2254734
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发表时间：
2023
影响因子：
1.3
通讯作者：
Daou J
中科院分区：
文献类型：
--
作者：
Daou J
研究了厚平面预混火焰沿单向剪切流横向稳定传播的稳定性。在无限大活化能的渐近极限下进行了线性稳定性分析，得到了色散关系。该关系描述了泰勒扩散（或剪切增强扩散）与火焰热扩散不稳定性之间的耦合，用两个主要参数来表示，即反应物刘易斯数和流动佩克莱数。讨论了色散关系的含义，并在平面上对各种火焰不稳定性进行了识别和分类。一个重要的原始发现是证明，当佩莱特数超过临界值时，通常发现的经典细胞不稳定性现在存在，但不存在。事实上，细胞不稳定性可以通过有限波长稳定分岔（也称为i型）或长波稳定分岔（也称为ii型）发生。后一类分岔导致弱非线性状态下的Kuramoto-Sivashinsky方程，该方程是确定的。至于振荡不稳定性，通常在没有泰勒色散的混合物中遇到，如果佩莱特数足够大，则发现不存在振荡不稳定性。稳定性的发现，从色散关系推导出的解析，补充和数值检验了有限值的Zeldovich数。数值研究包括线性稳定性边值问题的特征值计算和时变控制偏微分方程的数值模拟。计算结果与分析预测结果在定性上是一致的。
The stability of a thick planar premixed flame, propagating steadily in a direction transverse to that of unidirectional shear flow, is studied. A linear stability analysis is carried out in the asymptotic limit of infinitely large activation energy, yielding a dispersion relation. The relation characterises the coupling between Taylor dispersion (or shear-enhanced diffusion) and the flame thermo-diffusive instabilities, in terms of two main parameters, namely, the reactant Lewis numberand the flow Peclet number. The implications of the dispersion relation are discussed and various flame instabilities are identified and classified in the-plane. An important original finding is the demonstration that for values of the Peclet number exceeding a critical value, the classical cellular instability, commonly found for, exists now forbut is absent when. In fact, the cellular instability identified foris shown to occur either through a finite-wavelength stationary bifurcation (also known as type-I) or through a longwave stationary bifurcation (also known as type-II). The latter type-IIbifurcation leads in the weakly nonlinear regime to a Kuramoto-Sivashinsky equation, which is determined. As for the oscillatory instability, usually encountered in the absence of Taylor dispersion inmixtures, it is found to be absent if the Peclet number is large enough. The stability findings, which follow from the dispersion relation derived analytically, are complemented and examined numerically for a finite value of the Zeldovich number. The numerical study involves both computations of the eigenvalues of a linear stability boundary-value problem and numerical simulations of the time-dependent governing partial differential equations. The computations are found to be in good qualitative agreement with the analytical predictions.
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泰勒色散和热膨胀对窄通道内火焰传播的影响
影响因子：
3.7
作者：
P. Pearce;J. Daou
通讯作者：
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动量和热损失对准二维预混火焰大尺度稳定性的影响
DOI：
--
发表时间：
1994
期刊：
影响因子：
--
作者：
G. Joulin;G. Sivashinsky
通讯作者：
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预混燃烧中的泰勒色散：层流火焰的湍流燃烧问题的答案
DOI：
--
发表时间：
2018
期刊：
影响因子：
--
作者：
J. Daou;P. Pearce;F. Al
通讯作者：
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流动引起的各向异性扩散和热损失下的火焰稳定性
影响因子：
4.4
作者：
Daou J
通讯作者：
Daou J
影响因子：
1.3
作者：
Rajamanickam P
通讯作者：
Rajamanickam P