稀疏泡状流中三维变形气泡的双投影测量技术

为研究气泡变形对泡状流中气泡受力与运动的影响,设计了一种可获得稀疏泡状流中变形气泡三维参数的双投影测量技术:经图像处理得到变形气泡的两幅投影椭圆后,针对变形气泡特点改进了调整椭圆参数以满足极线约束的预处理方法,并基于对偶空间理论建立了变形气泡的双投影三维重构算法,改进了已有算法中对三维模型与其二维投影间映射关系的处理。在稀疏泡状流中的实验结果表明此技术可较准确地测得变形气泡三维参数,实验误差小于12%。

Three-dimensional bubble deformation measured by double shadow images in dilute bubbly flow

A double-shadow-images technique was developed to measure the three-dimensional deformation of a bubble in a dilute bubbly flow to investigate forces on the bubble and its lateral motion.Two elliptical projections of the deformed bubble were obtained using image processing techniques.Then,a pre-processing procedure was used to adjust the parameters of the projected ellipses of the bubble according to the epipolar geometry constraint.Finally,an algorithm was then used to reconstruct the three-dimensional bubble shape from the two ellipsoidal projection contours based on the dual-space theory.An error analysis shows that the measurement error is usually less than 12%,so the technique can be used to measure bubble deformation in dilute bubbly flows.