CFD simulation of local scouring around airfoil-shaped bridge piers with and without collar

Ghaderi, Amir; Abbasi, Saeed

doi:10.1007/s12046-019-1196-8

Cited by 32 publications

(18 citation statements)

References 20 publications

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“…Moreover, for a dike with an orientation angle of 45 • (toward downstream), these waves can hardly be observed, and their effect on the horseshoe vortex was negligible. [36]).…”

Section: Resultsmentioning

confidence: 99%

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Velocity Field and Turbulence Structure around Spur Dikes with Different Angles of Orientation under Ice Covered Flow Conditions

Jafari

Sui

2021

Water

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Spur dikes are well-known structures that are widely used in rivers and coastal regions. Depending on their types, sizes, and orientation angles, spur dikes can substantially change flow characteristics. Results of previous studies indicate that the presence of an ice cover in rivers can cause complicated flow structures. The present experimental study investigates velocity fields and turbulence structures in the vicinity of spur dikes under ice cover with different roughness coefficients. The spur dikes were set up at the following three angles of orientation, 90°, 60°, and 45°. Our results show that the strongest velocity fluctuation occurs immediately above the scour hole surface and very close to the dike tip. The increase in the dike angle toward upstream, the velocity component values increase, leads to a larger scour hole. Results show that an increase in dike angle of each 10° (from 45° to 90°) increases the scour depth between 5% and 10%, depending on flow conditions. Furthermore, the increase in the cover roughness coefficient and the blockage ratio of a spur dike leads to a further increase in turbulence kinetic energy and 3D velocity components values. The findings of this study imply that the appearance of an ice cover can increase turbulence intensities up to nearly 30%.

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“…Moreover, for a dike with an orientation angle of 45 • (toward downstream), these waves can hardly be observed, and their effect on the horseshoe vortex was negligible. [36]).…”

Section: Resultsmentioning

confidence: 99%

“…This fact explains the development of the deposition ridge downstream of the dike (Figure 6). [36]).…”

Section: Resultsmentioning

confidence: 99%

Velocity Field and Turbulence Structure around Spur Dikes with Different Angles of Orientation under Ice Covered Flow Conditions

Jafari

Sui

2021

Water

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“…FLOW-3D ® software package was used to numerically simulate the flow pattern. The software solves the three-dimensional Reynolds averaged Navier-Stokes equations (RANS) with the finite volume method [32,33]:…”

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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“…This software can be used to model 3D unsteady free surface flows with complicated geometry in which the volume of fraction (VOF) method is utilized. The governing equations are the Navier-Stokes Ghaderi and Abbasi 2019) and continuity equations. The general form of the continuity equation is:…”

Section: Continuity Equations Momentum and Free Surfacementioning

confidence: 99%

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

et al. 2019

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Side weirs are utilized to regulate water surface and to control discharge and water elevation in rivers and channels. Here, the discharge coefficient for trapezoidal sharp-crested side weirs (TSCSW) and their affecting parameters are numerically investigated. To simulate the hydraulic and geometric characteristics of TSCSWs, three weir crest lengths of 15 cm, 20 cm and 30 cm with lengths of 20 cm, 30 cm and 40 cm and with two different sidewall slopes are utilized. The results show that for constant P/B (P: weir height, B: main channel width), the depth of flow along the channel and weir decreases as the crest length increases. Also, with increasing P/y 1 ratio (P: weir height, y 1 : upstream flow depth), the discharge coefficient decreases for small crest lengths and increases for large crest lengths. The results show that for constant T/L ratio (T: passing flow width, L: side weir crest length), increasing the length, height and sidewall slope of a side weir will increase the discharge coefficient. It is observed that as the upstream Froude number increases for side weirs with longer crest lengths, the intensity of deviating flow and kinetic energy over the TSCSW will increase. Finally, some relations with high correlation factors are proposed for obtaining discharge coefficients using the dimensionless parameters of P/y 1 , T/L and Fr 1 . Based on proposed relations and sensitivity analysis, it is shown that T/L and P/y 1 are the most effective parameters for reducing the discharge coefficient reduction.

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CFD simulation of local scouring around airfoil-shaped bridge piers with and without collar

Cited by 32 publications

References 20 publications

Velocity Field and Turbulence Structure around Spur Dikes with Different Angles of Orientation under Ice Covered Flow Conditions

Velocity Field and Turbulence Structure around Spur Dikes with Different Angles of Orientation under Ice Covered Flow Conditions

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

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

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