基于圆管内近球形颗粒-液两相流的三维颗粒图像测量技术

Three-dimensional particle image measurement technique for spheroid particle-liquid two-phase flows inside round tube

应用三维颗粒图像跟踪技术,对竖直圆管内发泡聚苯乙烯-油层流两相流中分散相即颗粒相瞬时分布进行非接触测量。实验用一面与正视方向成45°的平面镜将流场的侧视方向反射到正视方向,摄像机连续将流场瞬时的侧、正视像同时拍摄下来,对图像进行识别等数字化处理后就获得了颗粒像的二维平面位置。分析摄像系统的成像关系,校正摄像系统的误差,确定颗粒在竖直方向、管径方向、灰度值等方面的匹配条件,再通过侧、正视图的匹配操作找回颗粒中心的三维空间位置,为两相流的相分布测量提供了高精度的新方法。

With a three-dimensional particle image tracking technique （ PIT）, the instantaneous distribution of particles （the disperse phase） was non-intrusively measured for upwards laminar large and spherical expanded polystyrene particle-oil two-phase flow in a vertical pipe. In the experiment a mirror is used to reflect the side direction of the view window of the flow field to the front direction, which is mounted by the side of the view window of the flow field at an angle of 45° to its front direction, and then a camera （CCD） continuously shots the instantaneous front and side views of the flow field simultaneously; the 2-dimensional positions of the particle images are obtained after digital image processing such as image recognition; the 3D positions of particles are determined by analyzing the imaging relation, correcting the error of 3D photographic system, determining the conditions of particle image matching in terms to vertical direction, radial direction, image gray scale and other factors, and matching the particle front images with side ones, which provides a new accurate method for measuring the phase distribution structure of the suspension particles in two-phase flow.