High resolution imaging of flameless and distributed turbulent combustion
High resolution imaging of flameless and distributed turbulent combustion
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DOI：
10.1016/j.combustflame.2011.06.018
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发表时间：
2012-01-01
影响因子：
4.4
通讯作者：
Alden, M.
中科院分区：
文献类型：
--
作者：
Duwig, C.;Li, B.;Alden, M.
用平面激光诱导荧光(PLIF)和瑞利散射方法研究了无火焰或温和燃烧等分布式反应过程中的湍流/燃烧相互作用。一种新型的实验室规模燃烧器(分布式无焰燃烧燃烧器-DFCB)被用来获得独特的高卡洛维茨数，目前报道高达14,400。该燃烧器由一个高度湍动的高速射流燃烧器组成，并带有污染同向流。报告了六个病例，其中两个病例(较瘦的病例)导致了一个不可见的反应区，尽管仍在紫外线和近红外范围内发射光线。同时获得了空间分辨率为50微米的OH/CH2O PLIF图像，以捕捉化学反应层中中间体的变化。当与瑞利散射测量获得的温度图像相辅相成时，它提供了对反应前沿结构的洞察以及火焰刷子厚度的测量。特别是，射流速度的变化突出了湍流混合(从而湍流/化学相互作用)对火焰结构的影响，如形成相对较大的CH2O池所描述的那样。此外，喷流化学计量比的变化对反应区能见度的影响很小，但对OH和CH2O信号的强度和整体形状影响不大。(C)2011年，燃烧研究所。爱思唯尔公司出版，版权所有。
Planar laser-induced fluorescence (PLIF) and Rayleigh scattering measurements were used for the study of turbulence/combustion interactions in distributed reaction regimes including flameless or MILD combustion. A novel laboratory scale burner (Distributed and Flameless Combustion Burner - DFCB) was used to reach uniquely high Karlovitz numbers, presently reported up to 14,400. It consists of a highly turbulent piloted high speed jet burner with a vitiated coflow. Six cases are reported whereas two of them (leaner cases) led to an invisible reacting zone, though still emitting light in the UV and near infrared range. Simultaneous OH/CH2O PLIF image with 50 mu m spatial resolution were achieved to capture the variation of intermediate species in the reaction layer. When complemented with temperature images obtained by Rayleigh scattering measurement, it provided insights of the reaction front structures as well as measures of the flame brush thicknesses. In particular, variations in the jet velocity highlighted the influence of turbulent mixing (hence turbulence/chemistry interaction) on the flame structures as depicted by the formation of relatively large pools of CH2O. Further, variations in the jet stoichiometry impacted on the reaction zone visibility but only marginally on the intensity and moderately on the overall shape of the OH and CH2O signals. (C) 2011 The Combustion Institute. Published by Elsevier Inc. All rights reserved.