Linear and weakly nonlinear instability of a premixed curved flame under the influence of its spontaneous acoustic field
Linear and weakly nonlinear instability of a premixed curved flame under the influence of its spontaneous acoustic field
复制标题
自发声场影响下预混弯曲火焰的线性和弱非线性不稳定性
DOI：
10.1017/jfm.2014.525
复制
发表时间：
2014
影响因子：
3.7
通讯作者：
Assier R
中科院分区：
文献类型：
--
作者：
Assier R
使用渐近公式研究了管道中预混火焰的稳定性，该公式源自第一原理并基于高活化能和低马赫数假设（Wu等人，流体力学杂志，第497卷，2003，第23-53页）。该方法考虑了火焰与其自发声场之间的动力学耦合，以及流体动力场与火焰之间的相互作用。重点是燃烧不稳定性的基本机制。为此，一些稳定的弯曲火焰的线性稳定性分析进行。这些稳定的火焰被认为是稳定的，当自发声扰动被忽略。然而，我们证明，他们实际上是不稳定的，当后者的影响。为了证实这一结果，并提供一个相对简单的模型指导主动控制，我们推导出一个扩展的迈克尔逊-Sivashinsky方程，它支配的线性和弱非线性的扰动火焰的自发声的影响下的演变。初值问题的数值解证实了线性不稳定性的结果，并显示了火焰如何随时间非线性发展。研究还表明，在一定的参数范围内，自发声可以引起较强的二次亚谐参数不稳定性。这种行为是解释和合理的数学诉诸Floquet理论。最后，我们比较我们的理论结果与实验观察，表明我们的模型捕捉到一些观察到的行为传播火焰。
The stability of premixed flames in a duct is investigated using an asymptotic formulation, which is derived from first principles and based on high-activation-energy and low-Mach-number assumptions (Wu et al., J. Fluid Mech., vol. 497, 2003, pp. 23–53). The present approach takes into account the dynamic coupling between the flame and its spontaneous acoustic field, as well as the interactions between the hydrodynamic field and the flame. The focus is on the fundamental mechanisms of combustion instability. To this end, a linear stability analysis of some steady curved flames is undertaken. These steady flames are known to be stable when the spontaneous acoustic perturbations are ignored. However, we demonstrate that they are actually unstable when the latter effect is included. In order to corroborate this result, and also to provide a relatively simple model guiding active control, we derived an extended Michelson–Sivashinsky equation, which governs the linear and weakly nonlinear evolution of a perturbed flame under the influence of its spontaneous sound. Numerical solutions to the initial-value problem confirm the linear instability result, and show how the flame evolves nonlinearly with time. They also indicate that in certain parameter regimes the spontaneous sound can induce a strong secondary subharmonic parametric instability. This behaviour is explained and justified mathematically by resorting to Floquet theory. Finally we compare our theoretical results with experimental observations, showing that our model captures some of the observed behaviour of propagating flames.
登录
查看更多内容
影响因子：
3.7
作者：
C. Altantzis;C. Frouzakis;A. Tomboulides;M. Matalon;K. Boulouchos
通讯作者：
C. Altantzis;C. Frouzakis;A. Tomboulides;M. Matalon;K. Boulouchos
DOI：
--
发表时间：
--
期刊：
影响因子：
--
作者：
Mallard
通讯作者：
Mallard
弱受力不稳定预混火焰起皱的长度尺度
影响因子：
1.9
作者：
C.St. Pierre;J. Guy
通讯作者：
J. Guy
空间发展火焰不稳定性的实验与非线性模型方程的比较
影响因子：
4.6
作者：
G. Searby;Jean;G. Joulin
通讯作者：
G. Joulin
焓变影响下预混燃烧大活化能理论
影响因子：
3.7
作者：
WU X
通讯作者：
WU X