可视化聚焦纹影系统实现流场中的三维扰动成像  

Three-Dimensional Perturbation Imaging in Fluid Field with Visualized Focusing Schlieren System

作　　者：席锋[1,2] 秦华锋[1,2] 胡莉[1,2] 林睿[2] Xi Feng;Qin Huafeng;Hu Li;Lin Rui(Chongqing Engineering Laboratory for Detection,Control and Integrated System,Chongqing Technology and Business University,Chongqing 400067,China;School of Computer Science and Information Engineering,Chongqing Technology and Business University,Chongqing 400067,China)

机构地区：[1]重庆工商大学检测控制集成系统重庆市市级工程实验室,重庆400067 [2]重庆工商大学计算机科学与信息工程学院,重庆400067

出　　处：《光学学报》2021年第9期82-87,共6页Acta Optica Sinica

基　　金：国家自然科学基金(11804035);重庆市博士后项目(Xm2017070);重庆市科委基础前沿项目(cstc2017jcyjA1592)。

摘　　要：可视化成像系统可以实现流场中扰动信息的捕获。针对光学纹影系统,分别从理论和实验上对比研究了流场中的三维超声扰动成像。因三维超声场在光传播方向上引起的流体介质密度变化不同,光波穿过密度变化的流场时,其相位累积变化使图像不能真实反映声场的扰动特征。线型栅的聚焦纹影系统因其线型栅会产生多刀口滤波的作用,故不能对流场中的三维超声扰动场实现完整成像。为了获得流场中的三维扰动特征,提出了采用环型源栅和刀口栅的改进聚焦纹影系统。结果表明:由改进聚焦纹影装置得到的图像扰动特征与实际流场中超声扰动特征相一致;结合图像重构技术,实现了流场中三维复杂扰动的重构。The perturbation in a fluid field can be captured by a visualized imaging system.In an optical schlieren system,we theoretically and experimentally compared the images of three-dimensional perturbation in the fluid field.The variations of fluid density generated by three-dimensional ultrasonic field are different in the direction of light propagation.As a result,after the light passes through the density-changing fluid field,the images cannot truly reflect the perturbation in the acoustic field due to the phase accumulation.Focusing schlieren systems with parallel line grids also cannot image the three-dimensional ultrasonic perturbation in the fluid field because of their multiple cutoffs.For this reason,we proposed a modified focusing schlieren system with annulus source and cutoff grids to obtain the information about three-dimensional perturbation.The images obtained by the optimized system achieve the same characteristics with the ultrasonic perturbation in the actual fluid field.In combination with image reconstruction techniques,this system supports the reconstruction of complex three-dimensional perturbation in the fluid field.

关 键 词：成像系统 纹影系统 聚焦纹影系统 三维扰动 流场 

分 类 号：O436.1[机械工程—光学工程]