| The three-dimensional information of discrete phase such as geometrical figure, position and so on, is always needed in research of two-phase flow, while the three-dimensional information cannot be got from two-dimensional images. Visualization in Two-phase Flow can attain two/three dimensional monitor enclosed pipe, which is realized by 3D reconstruction with discrete phase in two-phase flow.This paper presents a contour connection algorithm to reconstruction the geometrics surface of discrete phase, using a series of images derived from Electrical Resistance Tomography (ERT) system ,then implement 3D display in personal computer using projecting technique in OpenGL.The main research work in the paper is as follows:(1)Considering the characteristics of ERT images, Image smoothing, Dilation and Erosion operation in Mathematical Morphology and so on, are applied in preprocessing .Then noise information in the images is filtered and the gray value change near edges is enhanced.(2) Edge detection is implemented to preprocessed images by Laplacian .Then derive the contours of discrete phase and thin them.Sampling a series of finite contour points from the contours by equal angles.(3) The coordinates in 3D space of every contour point be derived, depending on the relative positions and 2D coordinates of the contour points. Considering the characteristics of the geometrics surface of discrete phase a non-linear interpolation algorithm is designed to make the interpolated contour points more appropriate.(4) The geometrics surface of discrete phase is reconstructed by contour connection, using triangular patchs. Then realized 3D display, rotation and zoom in screen by algorithm for eliminating hidden surface, illumination Model, projection conversion and so on.Experimental results demonstrate that, contour connection algorithm is effective for 3D reconstruction with discrete phase in two-phase flow. This research will be a solid base for Visualization in Two-phase Flow. |
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