1992 Fiscal Year Final Research Report Summary
Measurement of Three Dimensional Velocity Vectors in a Flow Field Based on a Spatio-Temporal Correlation Method
| Project/Area Number |
03650352
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
計測・制御工学
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| Research Institution | Kobe University |
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Principal Investigator |
KIMURA Ichiro Kobe University, Faculty of Engineering Associate Professor, 工学部, 助教授 (60031134)
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| Co-Investigator(Kenkyū-buntansha) |
YAMASAKI Yoshiharu Kobe University, Faculty of Engineering, Research Assistant, 工学部, 教務職員 (90174648)
TADOKORO Satoshi Kobe University, Faculty of Engineering Research Associate, 工学部, 助手 (40171730)
TAKAMORI Toshi Kobe University, Faculty of Engineering Professor, 工学部, 教授 (10031098)
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| Project Period (FY) |
1991 – 1992
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| Keywords | Three-dimensional velocity vector / Flow visualization / Image processing / Spatio-temporal correlation |
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| Research Abstract |
A measurement system of 3-D velocity vectors is essential in analyzing a highly complex flow field.
In this study, a new measurement method of 3-D velocity vectors in a flow field using spatio-temporal correlation method was developed. It is an advanced method for 2-D velocity vector measurement using correlation. The method needs two travel particle images observed at a short distance in the flow direction. Each of the two images consists of frame time series. The 2-D information on a 3-D velocity vector can be obtained using spatial correlation. In addition, the temporal correlation gives information on the third dimension. A 3-D velocity vector is consequently obtained by calculating the spatio-temporal correlation between the two images. This system was actually applied to a simple 2-D flow and a 3-D flow with reverse flow to confirm the appropriateness of this technique and its measurement uncertainty was evaluated.
In comparison with a conventional stereoscopic measurement method, in which each tracer is tracked in a 3-D space, the following advantages were clarified.
1) The method has wide applications to visualized flow images because the images of tracer particles are observed as a spatial pattern.
2) A spatially high-density vector distribution is obtained in a flow cross section.
3) In principle, the method does not need any known information on the flow characteristics.
The disadvantage, however, is that only a velocity vector distribution on a slit plane is obtained. To solve the problem, an improved optical system including slits will have to be devised to obtain many 3-D velocity vectors over the entire 3-D flow field.
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