Flame front tracking in turbulent lean premixed flames using stereo PIV and time-sequenced planar LIF of OH
Flame front tracking in turbulent lean premixed flames using stereo PIV and time-sequenced planar LIF of OH
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DOI：
10.1007/s00340-009-3647-0
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发表时间：
2009-09-01
影响因子：
2.1
通讯作者：
Kaminski, C. F.
中科院分区：
文献类型：
--
作者：
Hartung, G.;Hult, J.;Kaminski, C. F.
本文描述了同时应用 OH 自由基的时间序列激光诱导荧光成像和立体粒子图像测速技术来测量稀薄和预混合 LP 湍流火焰中的火焰锋动力学。研究的火焰可以通过声学驱动，以模拟低压燃烧技术中重要的现象。结合新颖的图像后处理技术，我们展示了如何使用获得的数据来跟踪由照明激光片定义的平面中的火焰前沿轮廓。我们考虑化学和对流流体运动对观测到的位移动力学的影响，并分析湍流和声学强迫对观测到的等高线速度的影响，我们将其称为 s (d) (2D) 。我们表明，这个量是火焰湍流相互作用的一个有价值且敏感的指标，因为（a）它可以用现有的实验方法来测量，并且（b）因为计算数据，例如来自大涡流模拟的结果可以以相同的方式进行后处理。 s (d) (2D) 与三维火焰位移速度 s (d) 相关（与二维投影），但必须仔细考虑由于火焰表面的平面外对流运动和火焰表面法线角度的不确定性而产生的伪影。进行蒙特卡罗模拟来估计火焰前角分布的几种分布的这种影响，并且最终表明 s (d) (2D) 是我们研究的火焰中与 s (d) 相关的量的敏感指标。在研究的条件范围内，s (d) (2D) 随湍流强度和声学强迫幅度线性增加。
This paper describes the simultaneous application of time-sequenced laser-induced fluorescence imaging of OH radicals and stereoscopic particle image velocimetry for measurements of the flame front dynamics in lean and premixed LP turbulent flames. The studied flames could be acoustically driven, to simulate phenomena important in LP combustion technologies. In combination with novel image post processing techniques we show how the data obtained can be used to track the flame front contour in a plane defined by the illuminating laser sheets. We consider effects of chemistry and convective fluid motion on the dynamics of the observed displacements and analyse the influence of turbulence and acoustic forcing on the observed contour velocity, a quantity we term as s (d) (2D) . We show that this quantity is a valuable and sensitive indicator of flame turbulence interactions, as (a) it is measurable with existing experimental methodologies, and (b) because computational data, e.g. from large eddy simulations, can be post processed in an identical fashion. s (d) (2D) is related (to a two-dimensional projection) of the three-dimensional flame displacement speed s (d) , but artifacts due to out of plane convective motion of the flame surface and the uncertainty in the angle of the flame surface normal have to be carefully considered. Monte Carlo simulations were performed to estimate such effects for several distributions of flame front angle distributions, and it is shown conclusively that s (d) (2D) is a sensitive indicator of a quantity related to s (d) in the flames we study. s (d) (2D) was shown to increase linearly both with turbulent intensity and with the amplitude of acousting forcing for the range of conditions studied.