Wu Yingchun, Wu Xuecheng, Yao Longchao, Gréhan Gérard, Cen Kefa
Appl Opt. 2015 Mar 20;54(9):2514-23. doi: 10.1364/AO.54.002514.
The 3D measurement of the particles in a gas-solid pipe flow is of great interest, but remains challenging due to curved pipe walls in various engineering applications. Because of the astigmatism induced by the pipe, concentric ellipse fringes in the hologram of spherical particles are observed in the experiments. With a theoretical analysis of the particle holography by an ABCD matrix, the in-focus particle image can be reconstructed by the modified convolution method and fractional Fourier transform. Thereafter, the particle size, 3D position, and velocity are simultaneously measured by digital holographic particle tracking velocimetry (DHPTV). The successful application of DHPTV to the particle size and 3D velocity measurement in a glass pipe's flow can facilitate its 3D diagnostics.
气固管道流动中颗粒的三维测量极具意义，但由于各种工程应用中存在弯曲的管壁，这一测量仍具有挑战性。由于管道引起的像散，在实验中观察到球形颗粒全息图中的同心椭圆条纹。通过ABCD矩阵对颗粒全息术进行理论分析，可以用改进的卷积方法和分数傅里叶变换重建聚焦颗粒图像。此后，通过数字全息粒子跟踪测速技术（DHPTV）同时测量颗粒尺寸、三维位置和速度。DHPTV在玻璃管道流动中颗粒尺寸和三维速度测量方面的成功应用有助于其三维诊断。
