Darrieus - Landau instability, growing cycloids and expanding flame acceleration
Darrieus - Landau instability, growing cycloids and expanding flame acceleration
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DOI：
10.1088/1364-7830/1/4/004
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发表时间：
1997-04
影响因子：
1.3
通讯作者：
W. Ashurst
中科院分区：
文献类型：
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作者：
W. Ashurst
从点点火源传播到无限域的预混合火焰在火焰尺寸增长超过过渡半径后显示出不断增加的火焰速度。 Gostintsev 等人的实验通过关系式 R = R1 + At3/2 进行描述，其中 t 是点火时间，SL 是火焰燃烧速度，是热扩散率。根据实验结果确定无量纲函数a()等于0.0022，其中 是火焰上的密度比。在目前的工作中，火焰传播的二维拉格朗日模拟也显示出具有 3/2 幂律行为的径向增长。这是一个势流模型 - 不包括涡度。因此，达里厄斯-朗道流体动力学不稳定性本身可以产生火焰加速。数值结果总结为关系式 R = R1+(2/40)L(SLt/L)3/2，其中 L 是参考长度，是批量生产比，= - 1。将数值图中的速度跳跃区域等同...
A premixed flame, propagating away from a point ignition source into an unlimited domain displays an increasing flame speed after the flame size has grown beyond a transition radius. Experiments by Gostintsev et al are described by the relation R = R1 + At3/2, where t is the time from ignition and, where SL is the flame burning velocity and is the thermal diffusivity. The non-dimensional function a() is determined from the experimental results to be equal to 0.0022, where is the density ratio across the flame. In the present work, two-dimensional Lagrangian simulations of flame propagation also display a radial growth with a 3/2 power-law behaviour. This is a potential flow model - no vorticity is included. Hence, the Darrieus - Landau hydrodynamic instability by itself can generate flame acceleration. The numerical results are summarized by the relation R = R1+(2/40)L(SLt/L)3/2, where L is a reference length and is the volume production ratio, = - 1. Equating the zone of velocity jump in the numerical sc...