Study of Flow Bifurcation at Tic 30° Open Channel Junction When the Width Ratio of Branch Channel to Main Channel Is Large

Lama, Sunil Kumar; Kuroki, Masayuki; Hasegawa, Kazuyoshi

doi:10.2208/prohe.46.583

Cited by 13 publications

(10 citation statements)

References 3 publications

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“…Over the years few theoretical models have also been proposed to model the division of flow and sediment at diversions. Most of the formulations were based either on momentum balance between the branches of the channel (Lama et al, 2002), or the energy balance between branches of the channel (Herrero-Casas, 2013). Riad (1961) proposed a formula to predict the division of sediment between the two channels, which correlates the ratio of sediment moving into the two channels with the ratios of flow moving into the two channels.…”

Section: Introductionmentioning

confidence: 99%

Three‐dimensional numerical modeling of the Bulle effect: the nonlinear distribution of near‐bed sediment at fluvial diversions

Dutta

Wang

Tassi

et al. 2017

Earth Surf Processes Landf

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The Bulle effect is a phenomenon in which a disproportionately higher amount of near‐bed sediment load at a fluvial diversion moves into the diverted channel, even for cases in which the proportion of water (with respect to the main flow) entering the diversion channel is relatively small. This phenomenon has wide‐ranging implications for both engineered and natural systems: from efficient design of channels to redirect water and sediment for reclaiming sinking deltas, designing navigational channels that do not need frequent dredging, to morphological evolution of river bifurcations. The first ever, and one of the most extensive set of experiments conducted to explore this phenomenon, were conducted by Bulle in . In the current study the experiments conducted by Bulle have been simulated using an open‐source, free‐surface finite‐element‐based hydrodynamic solver. The main objectives were to explore to what extent the complex phenomenon of the Bulle effect at the scale of a laboratory experiment can be simulated accurately using Reynolds‐averaged Navier–Stokes (RANS)‐based hydrodynamic solver, and to understand the details of the hydrodynamics that Bulle could not analyze through his experiments. The hydrodynamics captured by the simulations were found to match the observations made by Bulle through his experiments, and the distributions of sediment at the diversion predicted by the numerical simulations were found to match the general trend observed in the laboratory experiments. The results from the numerical simulations were also compared with existing one‐dimensional models for sediment distribution at bifurcations, and the three‐dimensional numerical model was found to perform appreciably better. This is expected due to the complex flow features at the diversion, which can only be captured satisfactorily using a three‐dimensional hydrodynamic model. Copyright © 2017 John Wiley & Sons, Ltd.

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Section: Introductionmentioning

confidence: 99%

Three‐dimensional numerical modeling of the Bulle effect: the nonlinear distribution of near‐bed sediment at fluvial diversions

Dutta

Wang

Tassi

et al. 2017

Earth Surf Processes Landf

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“…Ramamurthy et al [18] found a linear relationship between the contraction area and the discharge ratio (the area increases with the increase in discharge ratio). Lama et al [19] found that the contraction flow width at the bottom of the zone is wider than at the surface.…”

Section: Introductionmentioning

confidence: 98%

Enhancing the Flow Characteristics in a Branching Channel Based on a Two-Dimensional Depth-Averaged Flow Model

Ali

Yusuf

Mohammed

et al. 2019

Water

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Natural rivers have many branching junctions. The flow in branching junctions is complex, owing to significant changes associated with flow dynamics and sediment transport that result in erosion and deposition problems. A branching channel of the Tigris River in Missan, Iraq, was selected for investigation of the scouring and deposition zones. A two-dimensional (2D) numerical model was used to simulate the hydro-morphodynamics in the branching channel, where hypothetical vanes as control structures were included at the junction to control the scouring and deposition zones. The simulation results suggest the most effective location, dimension, and angle of the introduced vanes. For the studied junction, controlling morphological features was achieved by introducing a single vane with an inclination angle of 90° on the flow direction of the Tigris River. The most effective location of the introduced vane was the location that caused considerable enhancement in the flow depth and velocity distribution.

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“…In recent decades, extensive theoretical and experimental investigations of branching open channels have been performed to understand the characteristics of this branching flow. Branching channel flow still draws the attention of water resources engineering researchers as it commonly exists in many water engineering related projects, and due to the complexity of branching flow involving many interlinking factors it makes any generalization of the phenomenon difficult to achieve (Lama et al 2002). Studying the flow in the diversion channel has a direct application in water supply plants, water treatment plants, as well as irrigation and drainage network system design (Ramamurthy et al 1990).…”

Section: Introductionmentioning

confidence: 99%

“…Another aspect that influences the branching channel system is the branching angle. Lama et al (2002) noticed that the separation zone in the branch channel occurs in the downstream wall of a 30° branching angle. On the other hand, it occurs in the upstream wall of a 90° branching angle, e.g.…”

Section: Introductionmentioning

confidence: 99%

An experimental study of branching flow in open channels

Sayed

2019

Limnological Review

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Branching channel flow describes any side water withdrawals from rivers or main channels. Branching channels have widespread application in many practical projects, such as irrigation and drainage network systems, water and waste-water treatment plants, and many water resources projects. Therefore, in this research, a comprehensive analysis of laboratory data has been carried out to discover the best angle of branching. The study also aims to introduce simple, practical equations to help engineers of water resources to fix the percentage of discharge diverted to the branch channel. The study was carried out in the Irrigation and hydraulics laboratory of the civil department, Faculty of Engineering, Assiut University. The laboratory channel consisted of two parts, the main channel, and a branch channel. The main channel was 8.0 m in length, 20 cm wide, and 20 cm in depth. The division corner to the branch channel was sharp edged and located 5.0 m downstream of the main channel inlet. The branch channel was 3.0 m long, 20 cm in depth and its width was changed three times (10, 15, and 20 cm) respectively. A total of 84 runs were carried out. Investigations of the flow into the branching channel show that the branching discharge depends on many interlinked parameters. It increases with a decrease of the main channel flow velocity and the Froude number upstream of the branch channel junction. It also increases with an increase in the Yb / Yu ratio. In subcritical flow, water depth in the branch channel is always lower than the main channel water depth. The flow diversion to the branch channel leads to a decrease in water depth downstream of the main channel. In addition, the study showed that the highest discharge rate was obtained when the angle of branching was equal to 45° and then an angle of 60o. While the lowest discharge rate was obtained at an angle of 90°. Furthermore, at Br = 1.0, using a branching angle equal to 45° the discharge ratio (Qr) increases from about 4.42 to 19.01%, more than that obtained with using the branching angle equal 90°, while the discharge ratio (Qr) increases from about 0.52 to 49.18% and 1.51 to 24.79%, at Br = 0.75, and Br = 0.5 respectively.

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Study of Flow Bifurcation at Tic 30° Open Channel Junction When the Width Ratio of Branch Channel to Main Channel Is Large

Cited by 13 publications

References 3 publications

Three‐dimensional numerical modeling of the Bulle effect: the nonlinear distribution of near‐bed sediment at fluvial diversions

Three‐dimensional numerical modeling of the Bulle effect: the nonlinear distribution of near‐bed sediment at fluvial diversions

Enhancing the Flow Characteristics in a Branching Channel Based on a Two-Dimensional Depth-Averaged Flow Model

An experimental study of branching flow in open channels

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