| Summary: | 碩士 === 國立交通大學 === 土木工程系 === 90 === In this paper, the 2-D depth-averaged contaminant transport model incorporating with the secondary-current formulation was used to study the influence of the bend effect on the contaminant transport behavior in river bends. From the dimensional analysis, one obtained that the bend effect on the contaminant transport associates with seven independent dimensionless parameters. The regression analysis showed that the bend effect on the contaminant transport is mainly related to the relative strength of the secondary current and the relative length of the channel. The maximum relative difference on the contaminant concentration, obtained from the comparison of models with and without secondary-current formulations, is used to analyze the bend effect on the contaminant transport mechanism. Empirical relations between the maximum relative difference on the contaminant concentration, the relative strength of the secondary-current and the relative length of the channel for both channel-bend region and the straight region following the bend have been established. The field data reported by Lau and Krishnappan (1981) and Holley and Abraham (1973) are adopted herein to demonstrate the applicability and to verify the accuracy of the proposed relation.
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