Long Term Variations of Water Tempereture distributions in Lake Biwa
| Project/Area Number |
09650564
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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 |
水工水理学
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| Research Institution | KYOTO UNIVERSITY |
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Principal Investigator |
HOSODA Takashi Kyoto Univ., Civil Eng., Associate Prof., 工学研究科, 助教授 (10165558)
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| Co-Investigator(Kenkyū-buntansha) |
NAGATA Nobuhisa Kyoto Univ., Civil Eng., Research Associate, 工学研究科, 助手 (50273462)
OOKUBO Kenji Okayama Univ., Env. Design, Associate Prof., 環境理工学部, 助教授 (50135612)
MURAMOTO Yoshio Osaka College of Tech., Civil Eng., Prof., 建設土木学科, 教授 (50027223)
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| Project Period (FY) |
1997 – 1998
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| Project Status |
Completed (Fiscal Year 1998)
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| Budget Amount *help |
¥3,300,000 (Direct Cost: ¥3,300,000)
Fiscal Year 1998: ¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 1997: ¥2,300,000 (Direct Cost: ¥2,300,000)
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| Keywords | Lake Hydrodynamics / Stratification / Numerical Simulation / Hydraulic Engineering / 3次元流動解析 / 水理学 |
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| Research Abstract |
Water temperature in a lake is one of the most important indices to consider the lake environments. This research was carried out to develop a numerical model for the long term prediction of water temperature structure in Lake Biwa.
One dimensional models with 0-equation model and 2-equation k-ε model were firstly tested to simulate the vertical water temperature for one-year, using the monthly averaged meteorological data. It was shown that the calculated results by 0-equation model is in good agreement with the observed results generally, though it is needed to use the k-ε model to predict the strongly stratified temperature distribution.
In the one dimensional model, when a temperature at a depth is less then the averaged temperature over the depth, the temperatures over the depth are replaced to the averaged one to simulate natural convection due to the hydrodynamic instability. The natural convection occurring in a stratified lake was investigated by using 3-D numerical model with N-S equation. It was shown that, the downward flows caused by heat radiation at a water surface induce the mixing at the density interface, and lower the position of interface with the increase, of time.
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Report
(3 results)
Research Products
(8 results)
