Ma Lin, Lei Qingchun, Capil Tyler, Hammack Stephen D, Carter Campbell D
Opt Lett. 2017 Jan 15;42(2):267-270. doi: 10.1364/OL.42.000267.
This Letter reports the first direct comparison between two-dimensional (2D) and three-dimensional (3D) laser-induced fluorescence (LIF) applied to highly turbulent flames, with the goal of experimentally illustrating the capabilities and limitations of volumetric LIF (VLIF). To accomplish these goals, planar LIF (PLIF) and VLIF measurements were simultaneously performed on turbulent flames based on the CH radical. The PLIF measurements imaged a planar cross-section of the target flames across a 2D field-of-view (FOV) of 42 mm×42 mm. The VLIF measurements imaged the same region in the target flame with a 3D FOV of 42 mm×42 mm×5 mm, with 5 mm being the thickness of the measurement volume. The VLIF signals generated in this volume were captured by five intensified cameras from different perspectives, based on which a 3D tomographic reconstruction was performed to obtain the 3D reconstruction of the CH radical (as a marker of the flame front). The PLIF measurements were then compared to a cross-section of the VLIF measurement to demonstrate the feasibility and accuracy of instantaneous 3D imaging of flame topography and flame surface area in highly turbulent flames.
本信函报道了首次对应用于高湍流火焰的二维（2D）和三维（3D）激光诱导荧光（LIF）进行的直接比较，目的是通过实验说明体积LIF（VLIF）的能力和局限性。为实现这些目标，基于CH自由基对湍流火焰同时进行了平面LIF（PLIF）和VLIF测量。PLIF测量在42 mm×42 mm的二维视场（FOV）上对目标火焰的平面横截面进行成像。VLIF测量在目标火焰的相同区域进行，三维视场为42 mm×42 mm×5 mm，其中5 mm为测量体积的厚度。在该体积中产生的VLIF信号由五个增强型相机从不同角度捕获，在此基础上进行三维断层重建，以获得CH自由基（作为火焰前沿的标记）的三维重建。然后将PLIF测量结果与VLIF测量的横截面进行比较，以证明在高湍流火焰中对火焰形貌和火焰表面积进行瞬时三维成像的可行性和准确性。
