二维粒子图像测速系统的研制

A Particle Image Velocementry System for Two Dimensional Measurement

研制了一套二维粒子图像测速系统 ,该系统采用 CCD对流场中的示踪粒子视频图像进行采集 ,以拓扑映射的新方法完成粒子像对的匹配 ;整个过程无需人工干预 ,处理结果迅速、准确、可靠 ,如每处理一幅图像仅需 5分钟 ,匹配准确度达 95 %以上 ,其结果可给出被测流场的速度分量、速度矢量、等流函数线和等涡线等 .该系统与业已建成的多相分离实验模拟系统相配套 ,可用来对多种设备内流场进行多参数、多工况实验诊断 ,为揭示设备工作机理、优化设备结构等提供了有效手段 .

A two-dimensional PIV system has been developed, in which the particle images of the field to be measured are sampled with a CCD camera firstly, then to enchance the particle spots, the images were filtered and converted into two-value images. To find out the position of each particle, the boundary of the particle shapes were traced. To match the particle image produced by the same tracking-particle, a special algorithm called topological graphics has been used, so the particle image pairs could be found out automatically and reliably. Experiments show that only 5 minutes is needed for the system to analyze a flow field and the match precision was more than 95%. This system can give out the distribution of some flow parameters such as velocity vectors, X component of the velocity, Y component of the velocity, equivalent stream function and vorticity of the field to be tested. When combined with the simulating system of multiphase separation reported in literature , the PIV system can be used to diagnose the flow condition in a lot of engineering equipment.