Model development in OpenFOAM to predict spillway jet regimes

Wang, Y.; Politano, Marcela; Laughery, R.; Weber, Larry

doi:10.1080/23249676.2015.1025442

Cited by 8 publications

(4 citation statements)

References 33 publications

(34 reference statements)

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“…We tested this criterion by calculating the probability distribution of the most active turbulent length scales using the integral length scale (size of the largest, most‐energetic eddies) and Kolmogorov length scale (smallest effective eddy size) as reference. These turbulence scales were computed from the distributions of turbulent energy production and dissipation values predicted from an auxiliary K‐epsilon RANS model of the same domain (as per the theory discussed in Umlauf and Burchard, 2003; Wang et al ., 2015).…”

Section: Methodsmentioning

confidence: 99%

Sand settling through bedform‐generated turbulence in rivers

Yuill

Wang

Meselhe

et al. 2020

Earth Surf Processes Landf

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Fluvial bedforms generate a turbulent wake that can impact suspended-sediment settling in the passing flow. This impact has implications for local suspended-sediment transport, bedform stability, and channel evolution; however, it is typically not well-considered in geomorphologic models. Our study uses a three-dimensional OpenFOAM hydrodynamic and particle-tracking model to investigate how turbulence generated from bedforms and the channel bed influences medium sand-sized particle settling, in terms of the distribution of suspended particles within the flow field and particle-settling velocities. The model resolved the effect of an engineered bedform, which altered the flow field in a manner similar to a natural dune. The modelling scenarios alternated bed morphology and the simulation of turbulence, using detached eddy simulation (DES), to differentiate the influence of bedform-generated turbulence relative to that of turbulence generated from the channel bed. The bedform generated a turbulent wake that was composed of eddies with significant anisotropic properties. The eddies and, to a lesser degree, turbulence arising from velocity shear at the bed substantially reduced settling velocities relative to the settling velocities predicted in the absence of turbulence. The eddies tended to advect sediment particles in their primary direction, diffuse particles throughout the flow column, and reduced settling likely due to production of a positively skewed vertical-velocity fluctuation distribution. Study results suggest that the bedform wake has a significant impact on particle-settling behaviour (up to a 50% reduction in settling velocity) at a scale capable of modulating local suspended transport rates and bedform dynamics.

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Section: Methodsmentioning

confidence: 99%

Sand settling through bedform‐generated turbulence in rivers

Yuill

Wang

Meselhe

et al. 2020

Earth Surf Processes Landf

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“…Bubble velocity is calculated with an algebraic equation considering buoyancy, pressure and drag forces. The mathematical model, discretization schemes and boundary conditions of the numerical model are presented in Wang et al (2015Wang et al ( , 2018. The mass transfer at the free surface was neglected in the numerical model.…”

Section: Cfd Model Overviewmentioning

confidence: 99%

Installation of deflector in Colider Dam to minimize the percentual of total dissolved gases

Andriolo,

Araújo,

Fontanelli

et al. 2023

RBRH

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During voluntary or involuntary spills, the total dissolved gas (TDG) may increase with potential of causing gas bubble disease (GBD) in affected fish. Bubbles entrained during spill events in Colider are transported by plunging jets to deep, high pressure, regions in the tailrace where dissolution is enhanced increasing TDG concentrations. The most common alternative to minimize TDG supersaturation downstream of hydropower dams is to install deflectors on the spillway face. In order to reduce TDG levels downstream of the Colider's spillway, Copel retrofitted the four spillway bays with deflectors, finalizing the construction in November 2021. The design of the deflectors were assisted with two studies. The first study comprised the development of a physical model in 1:60 scale, and other study was a numerical model based on the open-source toolbox OpenFoam.

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“…This study resolves 3D flow structures in meandering channels using the 3D RANS equations, which are solved with OpenFOAM, an open-source computational fluid dynamics library based on the finite volume method. The OpenFOAM-based RANS models have been extensively used for analysis of open channel flows including bed erosion [28,38], hydraulic jump [39][40][41], spillway jet [41], flows around hydraulic structures [42][43][44], and coupled flows with porous media [45]. For incompressible fluid flows, the 3D RANS model adopts the Reynold approximation of continuity and momentum equations as follows:…”

Section: Hydrodynamic Modelmentioning

confidence: 99%

Evaluating the Impact of Turbulence Closure Models on Solute Transport Simulations in Meandering Open Channels

2020

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River meanders form complex 3D flow patterns, including secondary flows and flow separation. In particular, the flow separation traps solutes and delays their transport via storage effects associated with recirculating flows. The simulation of the separated flows highly relies in the performance of turbulence models. Thus, these closure schemes can control dispersion behaviors simulated in rivers. This study performs 3D simulations to quantify the impact of the turbulence models on solute transport simulations in channels under different sinuosity conditions. The 3D Reynolds-averaged Navier-Stokes equations coupled with the k − ε , k − ω and SST k − ω models are adopted for flow simulations. The 3D Lagrangian particle-tracking model simulates solute transport. An increase in sinuosity causes strong transverse gradients of mean velocity, thereby driving the onset of the separated flow recirculation along the outer bank. Here, the onset and extent of the flow separation are strongly influenced by the turbulence models. The k − ε model fails to reproduce the flow separation or underestimates its size. As a result, the k − ε model yields residence times shorter than those of other models. In contrast, the SST k − ω model exhibits a strong tailing of breakthrough curves by generating more pronounced flow separation.

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Model development in OpenFOAM to predict spillway jet regimes

Cited by 8 publications

References 33 publications

Sand settling through bedform‐generated turbulence in rivers

Sand settling through bedform‐generated turbulence in rivers

Installation of deflector in Colider Dam to minimize the percentual of total dissolved gases

Evaluating the Impact of Turbulence Closure Models on Solute Transport Simulations in Meandering Open Channels

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