1990 Fiscal Year Final Research Report Summary
Development of Laser Scan Lighting System for Flow Visualization
| Project/Area Number |
01850117
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| Research Category |
Grant-in-Aid for Developmental Scientific Research (B).
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| Allocation Type | Single-year Grants |
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| Research Field |
Hydraulic engineering
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| Research Institution | Tohoku University |
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Principal Investigator |
SAWAMOTO Masaki Tohoku Univ., Civil Eng., Professor, 工学部, 教授 (90016519)
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| Co-Investigator(Kenkyū-buntansha) |
NAGAO Masatomo Tohoku Univ., Civil Eng., Research Associate, 工学部, 助手 (20198302)
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| Project Period (FY) |
1989 – 1990
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| Keywords | Flow Visualization / Laser Scan / Image Processing |
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| Research Abstract |
The purposes of this research are to develop a new lighting system satisfying following items and to develop a image processing algorism in order to obtain a set of quantitative data from a flow visualization technique for high speed phenomena such as a wave breaking ;
1) to obtain a bright laser sheet lighting system by scanning a laser beam,
2) the laser sheet is parallel and uniform,
3) time lines are also recorded by pulsating the laser beam,
4) spacial scale is able to record in a image, and
5) the system has a good handling capacity.
The development of lighting system was performed successfully. But an additional modification of system needed because of noise from a laser beam scanner. Two kinds of system were tested ; one is introducing a optical fiber to transfer a laser beam and the other is without a fiber. It was confirmed that the former system has a room to modify to make light loss small but the later system satisfy the requirement of the researchers in fluid mechanics.
In developing a image processing technique, a new algorism was programmed to track tracers in a visualized image. The algorism was applied to an analysis of wave breaking and was confirmed that it gives a good result in estimating not only a flow field but also a vortisity field and two dimensional divergence.
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