中文摘要：

为了开展三维显微粒子追踪测速研究,设计了一种孔边缘厚度0.1mm,距挡板边缘间厚度成线性分布的三孔挡板,搭建了一套高速显微散焦粒子三维测速系统.通过光学和图像分析得到了工作介质粒子散焦图像构型参数和粒子深度方向的标定函数,并用二元多项式拟合获得了关于粒子平面位置的补偿函数,实现了粒子空间位置的识别和追踪.还针对倒置台阶结构的微通道流动进行了测量,采用20×0.4显微物镜和高速CMOS相机对通道内部播撒的2μm的荧光粒子进行了追踪,获得了粒子运动轨迹及三维速度分布.最后,采用数值仿真方法进行了验证,结果表明所搭建散焦测速系统和算法具有可行性和有效性.

英文摘要：

A high speed microscope defocusing particle velocimetry with a three-pinhole mask whose thickness was 0.1 mm at the edges of the three holes with linear distribution between every hole edge and mask edge was established for the three-dimensional microscopic particle tracking velocimetry. The calibration function between the configuration parameters of the defocusing particle image and the out-of-plane position of the particle was obtained by the optical and image analysis. The compensation functions by quadratic polynomial fitting of the in-plane position of the particle was obtained. The measurements of flow in a micro-channel with an inverted step structure were implemented. A microscope of objective lens of 20 × 0.4 and a high speed CMOS camera were employed to trace the fluorescent particles of 2μm in diameter in the measurements; and the three-dimensional velocities and the trajectory tracking of particles were obtained. The experimental result which is compared with the numerical simulation shows the feasibility of the particle defocusing image system and the validity of the arithmetic of particle tracking velocity.