数字全息粒子图像测速技术研究

 通过全息照相及再现的理论分析,进行了数字全息计算机数值模拟,利用快速傅里叶变换技术(FFT)对拍摄到的干涉条纹进行了图像复频域的信号分析,实现了数字全息的复频域滤波技术和全息图的小景深再现技术,应用于数字全息粒子图像测速DHPIV(Digital Holography Particle Image Velocimetry)技术.并对立方体对角复杂流动流场进行了试验测量,得到了空间中的三维速度向量场分布,进而得到了三维流线的空间分布,实现了具有时间序列全流场三维空间的三维速度场测量.

Research of digital holography PIV technique

The principal formula of digital holography was deduced and verified from the analysis of holography using Hugeness Fressnel theory and computer simulation. The thin focus depth of reconstructed 3 D digital image using in holography particle image velocimetry was created by a digital image phase filter method. The velocity vector field with 3 components in 3 D space was computed by 3 D cross correlation algorithm with thin depth image slices after using phase filter and non linear image filter. The 3 D vector and streamline results in a cubic flow field were achieved by using DHPIV technique. The results demonstrated an important step was made for the practicality of holography PIV.