Investigation of trapezoidal sharp-crested side weir discharge coefficients under subcritical flow regimes using CFD

Ghaderi, Amir; Dasineh, Mehdi; Abbasi, Saeed; Abraham, John

doi:10.1007/s13201-019-1112-8

Cited by 23 publications

(8 citation statements)

References 26 publications

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“…The RNG k-ε model improves the standard k-ε model (Equations ( 12) and ( 13)), reflecting small-scale effects by large-scale motion and modified viscosity terms, and can handle the flow with a large degree of curvature well [39]. This model showed satisfactory outcomes in previous studies on hydraulic engineering studies in complex geometry and flow fields [26,27,[40][41][42][43][44][45][46].…”

Section: Turbulence Modelmentioning

confidence: 78%

Prediction of Hydraulic Jumps on a Triangular Bed Roughness Using Numerical Modeling and Soft Computing Methods

et al. 2021

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This study investigates the characteristics of free and submerged hydraulic jumps on the triangular bed roughness in various T/I ratios (i.e., height and distance of roughness) using CFD modeling techniques. The accuracy of numerical modeling outcomes was checked and compared using artificial intelligence methods, namely Support Vector Machines (SVM), Gene Expression Programming (GEP), and Random Forest (RF). The results of the FLOW-3D® model and experimental data showed that the overall mean value of relative error is 4.1%, which confirms the numerical model’s ability to predict the characteristics of the free and submerged jumps. The SVM model with a minimum of Root Mean Square Error (RMSE) and a maximum of correlation coefficient (R2), compared with GEP and RF models in the training and testing phases for predicting the sequent depth ratio (y2/y1), submerged depth ratio (y3/y1), tailwater depth ratio (y4/y1), length ratio of jumps (Lj/y2*) and energy dissipation (ΔE/E1), was recognized as the best model. Moreover, the best result for predicting the length ratio of free jumps (Ljf/y2*) in the optimal gamma is γ = 10 and the length ratio of submerged jumps (Ljs/y2*) is γ = 0.60. Based on sensitivity analysis, the Froude number has the greatest effect on predicting the (y3/y1) compared with submergence factors (SF) and T/I. By omitting this parameter, the prediction accuracy is significantly reduced. Finally, the relationships with good correlation coefficients for the mentioned parameters in free and submerged jumps were presented based on numerical results.

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Section: Turbulence Modelmentioning

confidence: 78%

Prediction of Hydraulic Jumps on a Triangular Bed Roughness Using Numerical Modeling and Soft Computing Methods

et al. 2021

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“…They indicated that nappe breakers placed on the trapezoidal labyrinth weirs and circular labyrinth weirs reduced the discharge coefficient by up to 4% compared to an un-amended weir. Numerical methods have been used by various researchers in recent decades [12][13][14][15][16][17]. Shaghaghian and Sharifi [18] investigated the characteristics of flow in triangular labyrinth weirs using FLUENT.…”

Section: Figure 1 -Labyrinth Weir In a Channel With Converging Wallsmentioning

confidence: 99%

“…FLOW-3D ® is a general purpose computational fluid dynamics (CFD) program for modeling a wide variety of fluid flow fluid flow problems [13,20]. It uses the finite volume method to solve the RANS equations (Reynolds Average Navier-Stokes) in a Cartesian, staggered grid.…”

Section: Governing Equationsmentioning

confidence: 99%

Effect of Different Channels on Discharge Coefficient of Labyrinth Weirs

Daneshfaraz

Ghaderi

Abraham³

et al. 2021

Teknik Dergi

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In this study, the effect of channel-bed slope and non-prismatic converging channel on the discharge coefficient of labyrinth weirs is numerically investigated utilizing FLOW-3D model. Numerical simulation results show that modifying the labyrinth weir channel through both methods improves the discharge coefficient. Among the selected bed slopes and converging channel wall, the slope of β=4% and angle of θ=10° yielded the highest discharge coefficient. For a ratio H T /P=0.1, (H T : flow height, P: weir height) the discharge coefficient and discharge rate for bed slope and convergence angle case were 19.22%, 23.9% and 22.28%, 25.91% higher than for a conventional labyrinth weir in prismatic channel, respectively. Simultaneous application of a bed slope and convergence angle significantly increases the discharge coefficient and discharge value case were 28.64% and 30.42% higher than compared to the conventional case. Therefore, changing the bed slope and wall angle of the weir channel increases the discharge coefficient and in this type of weir and these design alterations should be considered in weir design.

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“…Here, the Renormalization Group (RNG) k-ε turbulence model was selected. This model has been applied to similar flow scenarios and is capable of providing accurate and efficient solutions [34][35][36][37][38]. The RNG k-ε model equations are given by:…”

Section: Numerical Modelmentioning

confidence: 99%

Energy Dissipation and Hydraulics of Flow over Trapezoidal–Triangular Labyrinth Weirs

Ghaderi

Daneshfaraz

Dasineh

et al. 2020

Water

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In this work experimental and numerical investigations were carried out to study the influence of the geometric parameters of trapezoidal–triangular labyrinth weirs (TTLW) on the discharge coefficient, energy dissipation, and downstream flow regime, considering two different orientations in labyrinth weir position respective to the reservoir discharge channel. To simulate the free flow surface, the volume of fluid (VOF) method, and the Renormalization Group (RNG) k-ε model turbulence were adopted in the FLOW-3D software. The flow over the labyrinth weir (in both orientations) is simulated as a steady-state flow, and the discharge coefficient is validated with experimental data. The results highlighted that the numerical model shows proper coordination with experimental results and also the discharge coefficient decreases by decreasing the sidewall angle due to the collision of the falling jets for the high value of H/P (H: the hydraulic head, P: the weir height). Hydraulics of flow over TTLW has free flow conditions in low discharge and submerged flow conditions in high discharge. TTLW approximately dissipates the maximum amount of energy due to the collision of nappes in the upstream apexes and to the circulating flow in the pool generated behind the nappes; moreover, an increase in sidewall angle and weir height leads to reduced energy. The energy dissipation of TTLW is largest compared to vertical drop and has the least possible value of residual energy as flow increases.

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Investigation of trapezoidal sharp-crested side weir discharge coefficients under subcritical flow regimes using CFD

Cited by 23 publications

References 26 publications

Prediction of Hydraulic Jumps on a Triangular Bed Roughness Using Numerical Modeling and Soft Computing Methods

Prediction of Hydraulic Jumps on a Triangular Bed Roughness Using Numerical Modeling and Soft Computing Methods

Effect of Different Channels on Discharge Coefficient of Labyrinth Weirs

Energy Dissipation and Hydraulics of Flow over Trapezoidal–Triangular Labyrinth Weirs

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