Abstract
Tidal exchange through a narrow entrance channel was studied experimentally with the use of a simplified hydraulic model. The inflowing water mass, visualized with dye solution, exhibits the shape of a starting plume with a starting vortex pair at its head. Because of their periodical formation by the tide, these are called the “tidal plume” and “tidal vortex pair”. The axis of the tidal plume deflects and undulates with a period 2 to 9 times that of the tide. Together with this undulation, the vortex pair becomes asymmetric. A circulating flow is formed in the bay which affects the shape of the inflowing and outflowing water masses. A part of the inflowing water mass flows out during the subsequent ebb, and this outflowing portion can be divided into two parts. One is the water remaining in the entrance channel at high water which flows out during the first half of the subsequent ebb and the other is the water flowing round the bay in the circulating flow during flood that flows out during the latter half of the subsequent ebb. Both contribute to the exchange ratio, but we can estimate an upper limit for the exchange ratio by neglecting the latter outflow. This neglected portion is considered in the concept of the age composition of outflowing water. The age composition of the bay water shows the existence of intermittent effluence superposed on a trend in the age composition that is similar to that of the well-mixed case. From the analysis of a model consisting of a number of mixing tanks connected in series with a recycle flow, it is concluded that this intermittent effluence occurs in the case of weak mixing due to the effect of circulating flow in the bay but is negligible in the case of strong mixing.
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References
Bolin, B. and H. Rohde (1973): A note on the concepts of age distribution and transit time in natural reservoir. Tellus, XXV, 58–62.
Danckwerts, P.V. (1953): Continuous flow system; Distribution of residence time. Chem. Engng. Sci.,2, 1–13.
Erricksson, E. (1971): Compartment models and reservoir theory. Ann. Rev. Ecol. Syst.2, 67–84.
Gilliland, E.R. and E.A. Mason (1952): Gas mixing in beds of fluidized solids. Ind. Eng. Chem.,44, 218–224.
Imasato, N., T. Awaji and H. Kunishi (1980): Tidal exchange through Naruto, Akashi and Kitan Straits. J. Oceanogr. Soc. Japan,36, 151–162.
Imasato, N., E. Hashimoto and T. Awaji (1983): Tidal exchange through a strait with two channels. Umi to Sora,58, 17–28 (in Japanese).
Kashiwai, M. (1984): The concept of tidal exchange and the tidal exchange ratio. J. Oceanogr. Soc. Japan,40, 135–147 (in Japanese).
Ketchum, B.H. (1951): The flushing of tidal estuaries. Sewage and Ind. Wastes,23, 198–209.
Levenspiel, O. (1962): Chemical Reaction Engineering. John Willey & Sons, Inc., New York, 501 pp.
Nir, A. and S. Lewis (1975): On tracer theory in geographical systems in the steady and non-steady state. Part I. Tellus, XXVII, 372–383.
Sugimoto, T. (1974): Similitude of the hydraulic model experiment for tidal mixing. J. Oceanogr. Soc. Japan,30, 260–270.
Yanagi, T., M. Kashiwai, H. Yasuda, H. Higuchi and Y. Kitagawa (1974): Fundamental study on the tidal residual circulation, Ann. Disaster Prevention Res. Inst. Kyoto Univ.,17B, 657–664 (in Japanese).
Zimmerman, J.T.F. (1976): Mixing and flushing of tidal embayment in the Western Dutch Wadden Sea. Part I. Neth. Sea Res.,10, 149–191.
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Kashiwai, M. A hydraulic experiment on tidal exchange. Journal of the Oceanographical Society of Japan 41, 11–24 (1985). https://doi.org/10.1007/BF02109927
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DOI: https://doi.org/10.1007/BF02109927