两相流显微PIV/PTV系统的开发

Development of the Microscopic PIT/PTV System for Two-Phase Flows

开发了一个能同时测量两相流中两相速度和细颗粒尺寸分布的显微PIV/PTV系统,其硬件系统包括大功率连续激光器、显微镜、高速摄像机;软件系统由改进的球形颗粒图像识别算法、各种图像处理算法和各种先进的PIV/PTV算法组成。其中改进的圆弧识别算法能够进行更准确地进行曲线分割而能对充满噪音并相互重叠的颗粒图像给出较好的识别结果。应用该PIV系统,可以在微秒和微米数量级上捕获细颗粒/气泡图像,并能较准确地同时得到两相速度、颗粒尺寸和浓度分布。对焚香可吸入颗粒物进行了速度和尺寸的同时测量,得到了较满意的结果。

A PIV system is developed. The system can simultaneously measure the velocities of each phase and size distribution of fine particles in two-phase flows with the microscopic function. The hardware devices of the system include the high-power continuous laser, microscope and high-speed camera. The software system is composed by the improved circle extraction algorithm, various image processing algorithms and PIV/PTV algorithms. The circle detection algorithm is improved by local averaging method and false intersection filtration method, and then it can make more accurate curve segmentation and give good recognition results even for the noisy and overlapped particle images, Using this PIV system, the particle images in two-phase flows can be captured on the time scale of microsecond and the space scale of micron to get the velocities of each phase and particle sizes. The system is used to effectively measure the smoke flow of burning incense and satisfactory results are obtained.