Planar Laser-Induced Fluorescence Imaging of Shock-Tube Flows with Vibrational Nonequilibrium
Planar Laser-Induced Fluorescence Imaging of Shock-Tube Flows with Vibrational Nonequilibrium
复制标题
振动非平衡激波管流的平面激光诱导荧光成像
DOI：
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发表时间：
1992
期刊：
影响因子：
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通讯作者：
R. Hanson
中科院分区：
文献类型：
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作者：
B. Mcmillin;Michael P. Lee;R. Hanson
本文报道了一氧化氮在激波加热的振动非平衡流中的单次平面激光诱导荧光图像。结果表明，平面激光诱导荧光成像是一种很有前途的多维高速流动诊断技术，因为它能够检查冲击结构并可视化和测量振动非平衡。研究的流量产生在激波管和氩气中的NO的稀释混合物组成。一个窄带ArF激光调谐到D +- X（0，1）R2（28.5）跃迁的NO在193.346 nm被用作激发源。使用增强的二维光电二极管阵列在与激发路径成90度处收集宽带荧光。所提供的图像包括正入射激波、正反射激波和二维钝头体上高温超声速流发展的四幅图像序列。分析了正激波下游区域的振动弛豫，并与基于已知弛豫率的计算结果进行了比较。
Single-shot planar laser-induced fluorescence images of nitric oxide in shock-heated flows with vibrational nonequilibrium are reported. The results demonstrate that planar laser-induced fluorescence imaging is a promising diagnostic technique for multidimensional high-speed flows because of its ability to examine shock structure and to visualize and measure vibrational nonequilibrium. The flows studied were generated within a shock tube and were composed of dilute mixtures of NO in argon. A narrow-band ArF laser tuned to the D +- X (0,1) R2 (28.5) transition of NO at 193.346 nm was used as the excitation source. The broadband fluorescence was collected at 90 deg to the path of excitation using an intensified, two-dimensional photodiode array. Images presented include a normal incident shock, a normal reflected shock, and a four-image sequence of the development of high-temperat ure supersonic flow over a two-dimensiona l blunt body. The vibrational relaxation in the downstream region of the normal shocks is analyzed and compared with calculations based on known relaxation rates.