1995 Fiscal Year Final Research Report Summary
Study on Mass Transfer between Surface Water and Sub-Surface Water
| Project/Area Number |
06650576
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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 |
水工水理学
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| Research Institution | Osaka Institute of Technology |
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Principal Investigator |
AYA Shirou Osaka Institute of Technology, Faculty of Eng., Associate Professor, 工学部, 助教授 (00026361)
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| Co-Investigator(Kenkyū-buntansha) |
AOKI Kazuo Osaka Institute of Technology, Faculty of Eng., Associate Professor, 工学部, 助教授 (20111916)
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| Project Period (FY) |
1994 – 1995
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| Keywords | Seepage folw, / Thin layr flows, / Folws on permeable boundary / Diffusion, / Dispersion, / Self-Purification / Mixing, / Mass exchange |
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| Research Abstract |
Flows on the permeable boundary was experimentally investigated, and the flow visualization technique revealed ; (1)permeable boundary is schematically classified into three layrs, and the layr A located on the top of boundary is the most active for vertical mass transport ; (2)its geometrical features, i.e., the length to depth ratio is about 0.25 and the depth is dependent on the grain size of boundary ; and (3)the three characteristic parameters of the mass transport between surface and sub-surface waters, i.e., the characteristic time, the mass exchange velocity, the diffusion coefficient were also investigated, and dimensional analysis disclosed the functional relationships between these three parameters, and hydraulic parameters and characteristic parameters of the boundary.
Flows from the underground water and the river waters and associated mass transport was investigated. (1)The absorption curves of salt was experimentally investigated and the hysteresis curves between absorption and desorption processes were clarified. (2)The flows between the underwater and the river was numerically investigated by means of saturated and un-saturated seepage theory and it is disclosed that the flow rate depend on the water surface elevation of he river water.
The concentration decay of the turbidity was also investigated by the field measurements and the laboratory study in the flumes with permeable boundaries. (1)Its characteristic velocity was studied by dimensional analysis.(2)The numerical experiment of the concentration decay in the river disclosed that it was caused by the dilution by the inflow from tributaries, and/or the mass transport and exchange between the river water and the sub-surface flows.
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