1987 Fiscal Year Final Research Report Summary
A Study for Utitizaion of the stream-tube model for analysis of diffusion phenomena in Japanese rivers.
| Project/Area Number |
61460166
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| Research Category |
Grant-in-Aid for General 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 | Toyohashi University of Technology |
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Principal Investigator |
YOTSUKURA Nobuhiro Professor, Toyohashi University of Technology, 工学部, 教授 (00182840)
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| Co-Investigator(Kenkyū-buntansha) |
NAKAMURA Shunroku Associate Professor, Toyohashi University of Technology, 工学部, 助教授 (10023300)
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| Project Period (FY) |
1986 – 1987
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| Keywords | Turbulent Diffusion In Open Channel Flows / Transport Model For open Channel flows / Two-Dimensional Advection Diffusion / 開水路の溶存質濃度 |
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| Research Abstract |
Major objectives of the research have been to evaluate, adapt, and utilize in Japanese rivers the stream-tube model for solute transport, Which was developed by the principal investigator while he was in U.S.A.
Duting the two-year period ending March, 1988, hiwever, experimental phases of the research namely, field site evaluation of the model and laboratory-flume tests of the two-equation model. could not be executed satisfactorily, partly because of the lack of facilities and equipements at the laboratory of the University. Some 80% of the Grant fund was spent in purchasing and installing necessary equipments and facilities, so that empirical phase of the research will continue in the future
Major accomplishment of the research is an in-depth reevaluation of the stream-tube model based on recent North American and European information. Important conclusions are as follows. 1) The model is one of the most suitable two-dimansional model for unsteady transport in steady non-uniform open-channel flows. 2) Analysis of transverse dispersion coefficients in non-uniform rivers requires a new approach beyond Taylor's dispersion theory. 3) Nondimensionalized transverse dispersion coefficients for huge rivers like the Amazon are not much different from those for small rivers and laboratory flumes, thus the effect of river scale is nonexistent. 4) In adapting transport models to Japanese rivers, a two-equation model is needed to take account of solute exchange between the main flow zone and the dead zone. 5) So long as a first-order decay is assumed, the description of nonconservative solute in two-dimensional transport can be related to that of conservative solutes
Two papers describing the above results were completed and will soon be submitted to outside journals for publication.
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