提出一种记录动态喷雾粒子场的数字全息实验系统。该系统采用数字同轴全息记录系统,利用连续波(CW)激光器和高速电荷耦合器件(CCD)数字记录动态喷雾粒子场的全息图,通过数字再现得到不同时刻粒子场再现像。对粒子场再现像进行自适应滤波,聚焦像合成,二值化,Roberts边缘提取,Hough变换和亚像素精度计算,得到粒子的直径和位置信息,给出了在不同喷油脉宽和不同测量点所记录的柴油雾场的数字全息图,以及在喷油脉宽8 ms时,三维(3D)粒子场空间分布、质量分数分布和沿x,y方向的索太尔平均直径(SMD)分布曲线。

An experimental system of digital holography for digitally recorded dynamic spray particle field is proposed. Hologram of dynamic particle field is recorded based on digital in-line holography arrangement with continuous wave (CW) laser and a high-speed charge coupled device (CCD),and the reconstructed images with different times are reconstructed numerically. The reconstructed images of a hologram of particle field are approached by adaptive filtering,and in-focus images of particle in the volume are integrated into a plane and binarized,and the edge of particle image by Roberts is extracted,then Hough transform and sub-pixel precision computing are completed,so the size and the position of particle are obtained. Digital holograms of diesel spray under different pulse widths of the injector and different measuring locations are given,and the three-dimensional (3D) distribution of particle field,and mass distribution and distribution of Sauter mean diameter (SMD) of the spray field along x-axis and y-axis are also given when pulse width of the injector is 8 ms.