| Project/Area Number |
08650199
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Fluid engineering
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| Research Institution | Nagoya Institute of Technology |
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Principal Investigator |
YAMADA Hideo Nagoya Institute of Tech., Faculty of Engineering, Professor, 工学部, 教授 (50021605)
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| Co-Investigator(Kenkyū-buntansha) |
NAITOH Takashi Nagoya Institute of Tech., Faculty of Engineering, Assistant, 工学部, 助手 (80242907)
GOTOH Toshoyuki Nagoya Institute of Tech., Faculty of Engineering, Assistant Prof., 工学部, 助教授 (70162154)
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| Project Period (FY) |
1996 – 1997
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| Project Status |
Completed (Fiscal Year 1997)
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| Budget Amount *help |
¥1,500,000 (Direct Cost: ¥1,500,000)
Fiscal Year 1997: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 1996: ¥1,000,000 (Direct Cost: ¥1,000,000)
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| Keywords | vortex ring / instability / secondary vortex / flow visualization / experiment / vortex method / 3-D渦法 / 安定問題 / レイノルズ数 |
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| Research Abstract |
This report is mainly an experimental one about a vortex ring and a vortex pair. According to the vortex theorem a vortex must be closed by itself or must touch a boundary. A vortex ring has the former configuration, while a vortex pair, produced experimentally in a laboratory, the letter one. A vortex ring and a vortex pair thus can be called elementary in this sense. Though thses vortices are elementary, they often play a crucial role in various flow fields. A vortex ring has characteristics such as stretching, twisting, vorticity concentration, diffusion, wavy distortion of a core, and entrainment of the ambient fluid. A turbulent flow genarally contains such phenomena with some complexity. Thus, the study of a vortex ring or a vortex pair is not only interesting in itself but important in the basic study of a turbulent flow.
Recently, the mutual interaction between a vortex and a solid wall has drawn attention as an important research subject in vortex dynamics. The significance of the present study lies in its basic and important findings about the flow field of the vortex interaction mentioned above. In this study we have chosen two kinds of solid surface a flat wall and a thin circular cylinder. The former is the fundamental when considering the interaction with a solid body ; the latter is not only fundamental but important from the viewpoint of engineering application. In this report the smoke visualization method is extensively applied in measuring flow fields. The results have been reported in Nagare, in a paper presented at the 7th Asian Congress of Fluid Mechanics, and in a partial contribution to a doctoral thesis by Naitoh, a coinvestigator in this research program.
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