A cross-correlation technique for velocity field extraction from particulate visualization
A cross-correlation technique for velocity field extraction from particulate visualization
复制标题
从颗粒可视化中提取速度场的互相关技术
DOI：
10.1007/bf00190391
复制
发表时间：
1991
影响因子：
2.4
通讯作者：
T. Ueno
中科院分区：
文献类型：
--
作者：
T. Utami;R. Blackwelder;T. Ueno
拍摄了几个位置的水平横截面的快速时间序列照片，拍摄了RED=3,900的紊流明渠水流。获得了一对摄影图像，每个位置的时间差为1.3V/uτ2。图像被数字化为8位数据，空间分辨率为2.5粘性尺度。采用变间隔空间相关技术来提取速度分量，而不是识别离散粒子。利用这一技术，在一对图片图像之间获取了光照强度的二维空间互相关。在小范围内进行相关，并利用相关系数的峰值来获得对流速度，得到速度的两个分量。计算了一些统计性质，并表明它们与以前的数据具有可比性。速度分量的空间相关性揭示了与湍流结构有关的一些独特特征。
A rapid time series of photographs of the horizontal cross-sections of severaly+locations were taken of a turbulent open-channel water flow withRed= 3,900. A pair of photographic images were obtained with a time difference of 1.3v/uτ2at eachy+locations. The pictures were digitized into 8 bit data with a spatial resolution of 2.5 viscous scales. Instead of identifying discrete particles, a variable interval spatial correlation technique was used to extract the velocity components. With this technique, two-dimensional spatial cross-correlations of the illumination intensities were taken between a pair of picture images. The correlations were taken over small areas and the peak of the correlation coefficients were used to obtain the convection velocity yielding theuandwcomponents of velocity. Some statistical properties were calculated and are shown to be comparable with previous data. Spatial correlations of the velocity components revealed some unique characteristics related to the structure of turbulence.