OH Planar Laser-Induced Fluorescence and Emission Imaging in High Pressure LOx/Methane Flames
OH Planar Laser-Induced Fluorescence and Emission Imaging in High Pressure LOx/Methane Flames
复制标题
高压 LOx/甲烷火焰中 OH 平面激光诱导荧光和发射成像
DOI：
10.2514/1.24895
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发表时间：
2007
影响因子：
1.9
通讯作者：
L. Vingert
中科院分区：
文献类型：
--
作者：
S. Candel;G. Singla;P. Scouflaire;C. Rolon;L. Vingert
本文研究了平面激光诱导OH荧光在高压液氧/甲烷火焰中的应用。随着压力的增加，OH荧光的最大水平降低，而干扰光强度增加。结果表明，只有通过适当地调整检测方案，才能获得合适的数据。需要对OH荧光进行窄带滤波以降低干扰信号的水平。对干扰光的分析表明，它与源自火焰周围区域的多环芳烃荧光有关。OH和多环芳烃荧光信号幅度在2.5MPa的压力下变得相当，这构成了标准成像的上限。低于该极限，火焰被很好地表征，并且具有在液氧射流附近发展的薄的、褶皱的OH层。最初的火焰片是连续的，但当液氧射流破裂时，它在下游变得高度波纹化。火焰边缘间隔距离大于几个LOX后唇缘尺寸，表明稳定性不如在液氧/氢火焰的情况下实现得好，在液氧/氢火焰的情况下，燃烧通常在距离喷射器小于一个唇缘尺寸处开始。
The application of planar laser-induced fluorescence of OH to high-pressure liquid oxygen/gaseous methane flames is investigated in this article. As pressure is increased, the maximum level of OH fluorescence decreases while an interfering light intensity increases. It is shown that suitable data can only be obtained by properly tuning the detection scheme. Narrowband filtering of OH fluorescence is required to reduce the level of interfering signals. An analysis of the interfering light indicates that it is associated with polycyclic aromatic hydrocarbon fluorescence originating from a region surrounding the flame. OH and polycyclic aromatic hydrocarbon fluorescence signal amplitudes become comparable at a pressure of 2.5 MPa which constitutes an upper bound for standard imaging. Below that limit the flame is well characterized and features thin, wrinkled OH layers developing in the vicinity of the liquid oxygen jet. The initial flame sheet is continuous but it becomes highly corrugated further downstream when the liquid oxygen jet breaks down. The flame edge standoff distance is greater than a few LOx post lip sizes indicating that stabilization is less well achieved than in the case of liquid oxygen/hydrogen flames where combustion typically begins at less than one lip size from the injector.