光学 精密工程, 2019, 27 (7): 1417, 网络出版: 2019-09-02
交叉标记显示的羟基标记速度矢量测量
Velocity vector measurements by hydroxyl tagging velocimetry based on crossed tagging and displaying
激光诊断 速度矢量测量 羟基分子标记示踪 交叉标记显示 laser diagnostics velocity vector measurement hydroxyl tagging velocimetry crossed tagging and displaying
摘要
针对流场二维速度矢量分布测量的需求, 提出了利用交叉标记显示的光路设置实现羟基分子标记示踪速度矢量的方法。该技术中通过将标记激光束和显示激光片交叉布置, 在激光片平面内形成交叉标记点用于流场示踪。与传统的交叉网格实现速度矢量测量的方式相比, 该方法简化了实验光路, 有利于在恶劣环境中的应用, 并且得到的标记为近似圆点, 标记位置的识别更加方便。通过对交叉标记显示产生的标记点图像的位置进行模拟识别运算, 获得了影响标记点位置识别精度的因素和规律。利用单标记点实验设置, 获得了射流火焰流场速度矢量及其浮动值, 结果显示在存在火焰OH背景干扰的情况下, 速度测量不确定度小于2.2 m/s; 利用柱面透镜阵列, 实现了3×20个标记点的速度矢量分布测量。研究结果表明了交叉标记显示方法进行分子标记速度测量的可行性。
Abstract
To measure the two-dimensional velocity vector distribution of the flow field, a method of crossed tagging and displaying to conduct velocity vector measurement based on hydroxyl tagging velocimetry was developed. In this technique, the tagging laser beam and the displaying laser sheet are intersected to form tagging spots for flow tracing. Compared with the traditional cross-grid method to realize velocity vector measurement, this method uses a simplified experimental light path, which is advantageous to application in harsh environments. Moreover, the tagging spots are approximate dots, which are more convenient for identifying the tagging positions. Through the simulated tagging spot images, precise values of the signal noise ratio, spot size, and tagging shape were obtained. The velocity and fluctuation in a jet flame were obtained by a single tagging spot, and the velocity uncertainty can reach 2.2 m/s while an OH background is present in the flame. By using a cylindrical lens group to shape the tagging laser beam into multiple lines, 3×20 tagging spots were formed to measure the velocity vector distribution in the jet flame.
叶景峰, 李国华, 邵珺, 胡志云, 陶波, 方波浪, 宋文艳. 交叉标记显示的羟基标记速度矢量测量[J]. 光学 精密工程, 2019, 27(7): 1417. YE Jing-feng, LI Guo-hua, SHAO Jun, HU Zhi-yun, TAO Bo, FANG Bo-lang, SONG Wen-yan. Velocity vector measurements by hydroxyl tagging velocimetry based on crossed tagging and displaying[J]. Optics and Precision Engineering, 2019, 27(7): 1417.