Mach Zehnder interferometric filter based planar Doppler velocimetry (MZI-PDV)
Mach Zehnder interferometric filter based planar Doppler velocimetry (MZI-PDV)
复制标题
基于马赫曾德尔干涉滤波器的平面多普勒测速 (MZI-PDV)
DOI：
10.1088/1464-4258/9/11/006
复制
发表时间：
2007
影响因子：
2.1
通讯作者：
R. Tatam
中科院分区：
文献类型：
--
作者：
Zenghai H. Lu;T. Charrett;H. Ford;R. Tatam
本文介绍了一种测量流场的平面多普勒测速系统。该技术使用Mach-Zehnder干涉滤波器将多普勒频移转换为强度变化。滤波器的自由光谱范围可以通过调节干涉仪的光程差来选择。这允许速度测量范围、灵敏度和分辨率变化。可以使用任何激光波长。描述了一种实验装置，该装置包括设计用于稳定干涉滤波器的锁相系统。提出了两种干涉条纹图像的处理方法。第一种方法使用条纹图案的位移来确定沿着轮廓的多普勒频移。第二种方法通过归一化图像中每个像素处的接收光强度来提供全场测量。这里给出的结果是对边缘最大速度为~ ± 70 m s−1的旋转圆盘的测量结果。两种方法测得的速度的标准偏差分别为2.9和2 m s-1。还介绍了对喷嘴直径为20 mm、出口速度为~85 m s-1的播种空气射流的测量。
A planar Doppler velocimetry system to measure flow velocity fields is described. The technique uses a Mach–Zehnder interferometric filter to convert Doppler frequency shifts into intensity variations. The free spectral range of the filter can be selected by adjusting the optical path difference of the interferometer. This allows the velocity measurement range, sensitivity and resolution to be varied. Any laser wavelength may be used. An experimental arrangement is described that incorporates a phase-locking system designed to stabilize the interferometric filter. Two techniques to process the interference fringe images are presented. The first uses the shift of the fringe pattern to determine the Doppler shift along profiles. The second provides a full-field measurement by normalizing the received light intensity at each pixel in the image. Results are presented here for measurements of a rotating disc with maximum velocities of ~ ± 70 m s−1 at the edge. Standard deviations in the measured velocities were found to be about 2.9 and 2 m s−1 for the two methods. Measurements on a seeded air jet with a nozzle diameter of 20 mm and an exit velocity of ~85 m s−1 are also presented.