Investigation of Twin Vortices near the Interface in Turbulent Compound Open-Channel Flows Using DNS Data

Joung, Younghoon; Choi, Sung-Uk

doi:10.1061/(asce)0733-9429(2008)134:12(1744)

Cited by 8 publications

(2 citation statements)

References 23 publications

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“…From the figure, it is also observed that the vertical interface velocity is peaked (−ve value) near the junction of the channel which further confirms that major part of the momentum transfer occurs between the layers in these locations of the channel. Similar result was obtained in the laboratory experiments and in the numerical studies by other researchers also in the past (Joung and Choi 2008;Kara et al 2012;Naot et al 1993;Tominaga and Nezu 1991).…”

Section: Spanwise and Vertical Flow Velocity At Interface (V 0 W 0 )supporting

confidence: 90%

Development of Two-layered model for compound open-channel flow

Sinha

Das

Patel

et al. 2014

ISH Journal of Hydraulic Engineering

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Present study deals with the development of two-dimensional two-layered model for straight compound open-channel flow using Smagorinsky-based subgrid-scale turbulence model, based on large eddy simulation approach. The two-layer depth averaged governing equations are solved using finite volume method based on MacCormack predictor-corrector explicit scheme. Model results for symmetric and asymmetric straight compound channel flows are verified with the available numerical and experimental data. Variations of flow variables in symmetric and asymmetric straight compound channels in terms of shear stress distributions and spanwise and vertical velocities are analyzed at the horizontal interface between the lower layer and the upper layer. Spanwise and vertical velocities at the horizontal interface revealed the existence of horizontal vortices near the junction of the main channel and the floodplain where momentum exchange takes place. Further, the model result, showing the spanwise shear stresses distribution at the interface of symmetric and asymmetric compound channel, revealed the existence of peak shear stress near the channel junction. Sensitivity of the two important model parameters is also undertaken and their roles in longitudinal velocity distribution along the channel width are discussed.

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Section: Spanwise and Vertical Flow Velocity At Interface (V 0 W 0 )supporting

confidence: 90%

Development of Two-layered model for compound open-channel flow

Sinha

Das

Patel

et al. 2014

ISH Journal of Hydraulic Engineering

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“…Numerical modelling of flow structure in vegetated compound channel is another important issue in compound open channel. To simulate mean flow and turbulence structure in compound open channel with vegetation on floodplain, many investigators (Tsujimoto et al 1991, Shimizu and Tsujimoto 1994, Fischer-Antze et al 2001, Helmio 2002, Kang and Choi 2005, Wilson et al 2006, Joung and Choi, 2008) developed some numerical model to compute velocity distributions in channels with submerged vegetation. The results were in agreement with measured velocity profiles.…”

Section: Introductionmentioning

confidence: 99%

How far must trees be cultivated from the edge of the flood plain to provide best river bank protection?

Esfahani

Keshavarzi

2010

International Journal of River Basin Management

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In this study, to find the best location to cultivate the trees for river bank protection, some experimental tests were performed. One row of trees were cultivated at five different distances from the main channel/floodplain interface in a rectangular compound open channel. In experimental model for simulating the trees, some cylindrical wood rods were attached to the bed of flood plain. The three-dimensional flow velocity of flow in a cross-section between the trees were measured in 149 nodal points using Micro-acoustic Doppler velocimeter (ADV) velocity meter. At each nodal point, 6000 velocity data for each direction were stored in a computer. From the analysis of the experimental data, it was concluded that upon cultivating trees at 10% distance of flood plain width from the edge of main channel, the minimum streamwise velocity occurred near main channel/floodplain interface, while the maximum streamwise velocity occurred far from the edge of floodplain. Therefore, the best location for cultivating the trees was found to be at 10% of floodplain width and it is suggested for river bank protection in practical applications.

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