• Journal of Wetlands Research
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• v.16 no.1
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• pp.139-151
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• 2014

In this study, virtual confluence of $30^{\circ}$, $45^{\circ}$, $60^{\circ}$, $75^{\circ}$ type flowing into main channel was designed to comprehend occlusion phenomenon of the mouth of river, then performed numerical analysis using the RMA-2 and SED2D model of SMS according to application of 40m, 60m, 80m, 100m Training levee corresponding to main channel width ratio. Results of simulations analysis are summarized as follows. Applying appropriate Training levee length determined by numerical analysis results, Training levee dimension for occlusion reduction was studied through the analysis of velocity, water level, bed variation at the Gamchen confluence and Wichen confluence.

• Proceedings of the KIEE Conference
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• 2002.07c
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• pp.1991-1993
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• 2002

This paper presents the PDMS surface characteristic change after the plasma process and the electroosmotic flow control technique for the two-dimensional focusing in the micro channels made of PDMS and glass. The channels are fabricated by plastic molding and micromachining technique. To observe the surface characteristic change as time elapses, we measure the contact angle of water on the surface and the velocity of the electroosmotic flow in a channel. The electric field adequate for focusing of a core flow in a confluence channel is obtained by the experiment. The computer simulation is performed to obtain the width and the depth of the core flow for several junction angles of the confluence channel.

• Journal of the Korean Society of Hazard Mitigation
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• v.6 no.1 s.20
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• pp.59-68
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• 2006

Flow separation of recirculation zone by increasing of flow and change of its direction at confluence results in backwater due to conveyance reduction. The hydraulic characteristics of flow separation are analysed by experimental results of flow ratios of tributary and main streams and approaching angles. The boundary of flow separation by dimensionless length and width is defined by the streamline of zero and this definition agrees well to the existing investigation. Because flow separation doesn't appear in small flow ratio and approaching angle of $30^{\circ}$, the equation of flow separation with flow ratio and approaching angle is provided. In flow separation consideration and comparing with previous results, the existing equations of dimensionless length and width ratios by function of approaching angle, flow ratio, and downstream Froude number are modified and also contraction coefficient and shape factor are analysed. Dimensionless length and width ratios are proportional to the flow ratio and approaching angle. In analysis of water surface profiles, the backwater effects are proportional to the flow ratio and approaching angle and the magnitude at outside wall is greater than that of inside wall of main stream. The length, $X_l$ from the beginning of confluence to downstream of uniform flow, where the depth is equal to uniform depth, is characterized by width of stream, flow ratio, approaching angle, and contraction coefficient. The ratios between maximum water depth by backwater and minimum depth at separation are analysed.