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Development and Validation of Two-Dimensional Velocity Measurement by Laser-induced Fluorescence Images

激光诱导荧光图像二维速度测量的开发和验证

基本信息

批准号：
13555055
负责人：
TAKAGI Toshimi
金额：
$ 8.64万
依托单位：
Osaka University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
2001
资助国家：
日本
起止时间：
2001 至 2002
项目状态：
已结题

项目摘要

The development and validation of velocity-vector profile measurement, which was derived from a pair of Laser-induced fluorescence images (FIV: Fluorescence Image Velocimetry) was carried out by a double-pulse laser optical system and the cross correlation technique. A pair of LIF images that has the different wavelength from the incident laser can distinguish that from Mie scattering. Vapor of biacetyl was used as a fluorescent gas and it was mixed to the main flow with tracer particles. Velocities were measured by cross correlation between a pair of biacetyl-LIF images. The velocity vectors by FIV were compared with the velocity vectors derived from the PTV by the double-exposed Mie scattering image of tracer particles. The result shows that velocity vectors derived from FIV agree well with those derived from PTV. The agreement was improved by changing the size of the reference matrix.The fluid velocity were compared with the displacement velocity of inhomogeneous concentration or particles distribution in an unsteady non-reacted jet with a large-scale vortex by the numerical simulation and cross correlation techniques in order to investigate performance of Scalar Image Velocimetry. The obtained results are as follows. (1) When the smaller size of inhomogeneous concentration distribution than that of the vortex is given, the displacement velocity agrees with the fluid velocity by using the similar reference size to the species concentration distribution. (2) The displacement velocity relatively does not agree with the fluid velocity in the case that the concentration distribution merges and dissipates with time, or it is distorted by the vortex. (3) The fluid velocity fairly agrees with the displacement velocity of the particle distribution as compared with that of the concentration distribution because the size of the particle distribution might be smaller than that of the concentration distribution.

速度矢量轮廓测量的开发和验证是通过双脉冲激光光学系统和互相关技术从一对激光诱导荧光图像（FIV：荧光图像测速）中获得的。一对与入射激光波长不同的 LIF 图像可以将其与米氏散射区分开来。使用联乙酰蒸气作为荧光气体，并将其与示踪粒子混合到主流中。通过一对联乙酰-LIF 图像之间的互相关来测量速度。将 FIV 的速度矢量与通过示踪粒子的双重曝光米氏散射图像从 PTV 导出的速度矢量进行比较。结果表明，FIV 导出的速度矢量与 PTV 导出的速度矢量非常吻合。通过改变参考矩阵的大小来提高一致性。通过数值模拟和互相关技术，将流体速度与具有大尺度涡流的非定常非反应射流中不均匀浓度或颗粒分布的位移速度进行比较，以研究标量图像测速的性能。得到的结果如下。 (1) 当给定比涡流更小的非均匀浓度分布尺寸时，通过使用与物质浓度分布相似的参考尺寸，位移速度与流体速度一致。 (2)当浓度分布随时间融合消散或受到涡流扭曲时，位移速度与流体速度相对不一致。 (3) 与浓度分布相比，流体速度与颗粒分布的位移速度相当一致，因为颗粒分布的尺寸可能小于浓度分布的尺寸。