Friction Loss in Transition Regime in Rough Wall Channel
| Project/Area Number |
06650221
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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 |
Fluid engineering
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| Research Institution | Kanagawa Institute of Technology |
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Principal Investigator |
AKAIKE Shiro Kanagawa Institute of Technology Department of Technology, Professor, 工学部, 教授 (50017919)
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| Co-Investigator(Kenkyū-buntansha) |
NAKANE Ichiro Kanagawa Institute of Technology Department of Technology, Research Associate, 工学部, 助手 (30221451)
NEMOTO Mistumasa Kanagawa Institute of Technology Department of Technology, Research Associate, 工学部, 助手 (90085134)
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| Project Period (FY) |
1994 – 1995
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| Project Status |
Completed (Fiscal Year 1995)
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| Budget Amount *help |
¥1,700,000 (Direct Cost: ¥1,700,000)
Fiscal Year 1995: ¥400,000 (Direct Cost: ¥400,000)
Fiscal Year 1994: ¥1,300,000 (Direct Cost: ¥1,300,000)
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| Keywords | Rough wall channel / Friction factor / Transition regime / Equivalent sand roughness / Arithmetic average roughness / Moody chart / 粗さ要素 / ムーデイ線図 |
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| Research Abstract |
The relationship between Reynolds number Re and friction factor lambda at transition regime is affected by many factors such as relative roughness, roughness element shape and so on. The purpose of this research is to clarify the friction characteristics of rough wall passage at transition regime.
Experimental studies were carried out for two-dimensional channel roughened by two-dimensional roughness elements which were made by rectangle. The height of roughness element is much less than the length of element in the flow direction and similar to the height of that of rough wall practically used. The working fluid is an air. The friction loss and the velocity distribution in the channel are measured.
The relationship between Re and lambda, and the correlation between the equivalent sand roughness Ks and the arithmetic average roughness Ra are discussed.
The results obtained are as follow.
(1) The friction factor lambda decreases with increasing the Reynolds number at the transition regime as well as Colebrook's formula which is used in Moody chart.
(2) It seems that the influence of the roughness element located at a distance on the friction factor does not depend on only Ra. Therefore, the correlation between Ks and Ra is not determined.
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Report
(3 results)
Research Products
(1 results)
