Cross-correlation Doppler global velocimetry (CC-DGV)
Cross-correlation Doppler global velocimetry (CC-DGV)
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DOI：
10.1016/j.optlaseng.2015.03.012
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发表时间：
2015-08
影响因子：
4.6
通讯作者：
D. Cadel;K. Lowe
中科院分区：
文献类型：
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作者：
D. Cadel;K. Lowe
一种流动测速方法，互相关多普勒全球测速（CC-DGV），提出了作为一个强大的，简化的，和高动态范围的实现多普勒全球/平面多普勒测速技术。对于每个速度样本，使用蒸气吸收光谱的几千兆赫的扫描，其中从流内的多普勒频移散射光和非多普勒频移参考光束两者获取信号。这些信号的互相关产生了它们之间的多普勒频移，在扫描的持续时间内平均。利用现有的设备，理论上可以同时测量从0 ms− 1到超过3000 ms− 1的速度，使该技术成为高速流动的理想选择。处理程序被证明是强大的对碘电池的蒸气压的大的变化，有利于在环境条件不能很容易地调节的设施中的系统的性能。该系统的验证进行了测量模型风涡轮机叶片边界层在1.83米的1.83米的亚音速风洞，激光多普勒测速仪（LDV）测量获得的CC-DGV的结果。对于正交流向、横向-水平和横向-垂直速度分量，CC-DGV的不确定度分别为±1.30 ms−1、±0.64 ms−1和±1.11 ms− 1，雷诺数为150万和200万时，LDV验证结果的均方根偏差分别为2.77 ms− 1和1.34 ms− 1。还提供了超音速喷流的体积平均速度测量结果，正交分量的速度不确定度为±4.48 ms−1、±16.93 ms−1和±0.50 ms− 1，并通过使用物理标度折叠数据进行自验证。
A flow velocimetry method, cross-correlation Doppler global velocimetry (CC-DGV), is presented as a robust, simplified, and high dynamic range implementation of the Doppler global/planar Doppler velocimetry technique. A sweep of several gigahertz of the vapor absorption spectrum is used for each velocity sample, with signals acquired from both Doppler-shifted scattered light within the flow and a non-Doppler shifted reference beam. Cross-correlation of these signals yields the Doppler shift between them, averaged over the duration of the scan. With presently available equipment, velocities from 0 ms−1to over 3000 ms−1can notionally be measured simultaneously, making the technique ideal for high speed flows. The processing routine is shown to be robust against large changes in the vapor pressure of the iodine cell, benefiting performance of the system in facilities where ambient conditions cannot be easily regulated. Validation of the system was performed with measurements of a model wind turbine blade boundary layer made in a 1.83 m by 1.83 m subsonic wind tunnel for which laser Doppler velocimetry (LDV) measurements were acquired alongside the CC-DGV results. CC-DGV uncertainties of ±1.30 ms−1, ±0.64 ms−1, and ±1.11 ms−1were determined for the orthogonal stream-wise, transverse-horizontal, and transverse-vertical velocity components, and root-mean-square deviations of 2.77 ms−1and 1.34 ms−1from the LDV validation results were observed for Reynolds numbers of 1.5 million and 2 million, respectively. Volumetric mean velocity measurements are also presented for a supersonic jet, with velocity uncertainties of ±4.48 ms−1, ±16.93 ms−1, and ±0.50 ms−1for the orthogonal components, and self-validation done by collapsing the data with a physical scaling.