1987 Fiscal Year Final Research Report Summary
Real-Time Velocity Measutement System for Three-Dimensional Flow Field using a Flow Visualization and Digital Image Processing Technique
| Project/Area Number |
61850031
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| Research Category |
Grant-in-Aid for Developmental Scientific Research
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| Allocation Type | Single-year Grants |
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| Research Field |
Fluid engineering
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| Research Institution | Institute of Industrial Science, University of Tokyo |
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Principal Investigator |
KOBAYASHI Toshio Institute of Industrial Science, Univ. of Tokey. Professor, 生産技術研究所, 教授 (50013206)
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| Co-Investigator(Kenkyū-buntansha) |
SAGA Tetsuo Institute of Industrial Science, Univ. of Tokyo. Assistant, 生産技術研究所, 助手 (30013220)
山川 正剛 (株)日立製作所, エネルギ研究所, 主任研究員
ARAKAWA Chuichi Faculty of Engineering, Univ. of Tokyo. Associate Prof., 工学部, 助教授 (30134472)
SAKAUCHI Masao Institute of Industrial Science, Univ. of Tokyo. Associate Prof., 生産技術研究所, 助教授 (30107370)
YAMAKAWA Masanori Energy Reserch Laboratory, Hitachi, Ltd. Researcher
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| Project Period (FY) |
1986 – 1987
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| Keywords | Flow Visualization / Digital Image Processing / Pathline Photograph / Velocity destribution / Tracer Method / Pursuit of pArticles / Real-Time / 三次元 |
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| Research Abstract |
The solid tracer technique is one of the popular and usefull techniques to analyse the flow fiels. In order to determine automatically the quantitative velocity data of the teo-dimansional flow fields with reverce flow from pathline photographs, two specitical computer algorithms have been proposed. Special efforts have been made in both algrithms to overcome the two improtant problems, namely the distinction of the intersectinf pathlines and the determination of the local flow direction. The first approach is to recogniz the positions of tracer partines in the instantanwous photographs at two time points. In this appeoach, the additional pathline photograph during two time points is used in order to find out the identical particles in the two instrantaneous photographs. The secons approach is the method of utilizing the pathline contours of tracer particles in a short-exposure photograph. The instantaneous flash is added at the biginning of the exposure by an electrically controlled stroboscope in order to distinguish the local flow direction. The automated image processing system constructed on the above algorithms in this study consists of two computer-controlled TV cameras and a synchronized stroboscopr, an analogue-digital converter, an image processet, an image memory and a mico-computer. This system has been applied successfully to quantitative measurements of floes around an airfoil cascade, a circular cylinder and rotating disks. The factors which have an effect on the system errors are investigated in detail. Finally the system has been developed to the real-time flow velocity measurement using a high speed algorithm and the three-dimensional flow velocity measutement using the streophotography.
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