Comparison of Different Turbulence Models for Numerical Simulation of Pressure Distribution in V-Shaped Stepped Spillway

A stepped spillway, which is defined as a spillway with steps on the chute, can be used to improve the energy dissipation of descending water. Although uniform stepped spillways have been studied comprehensively, non-uniform stepped spillways need more attention. In the interest of maximum energy dissipation, in this study, non-uniform stepped spillways were investigated numerically. To this end, within the range of skimming flow, four different types of non-uniform step lengths, including convex, concave, random, and semi-uniform configurations, were tested in InterFOAM. To evaluate the influence of non-uniform step lengths on energy dissipation, the height and number of steps in all models were fixed and equal to a constant number. The results indicated that in semi-uniform stepped spillways, when the ratio between the lengths of the successive steps is 1:3, a vortex interference region occurs within the two adjacent cavities of the entire stepped chute, and as a result, the energy dissipation increases by up to 20%.

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“…The results revealed that the realizable k-ε model is the most efficient. The same result was reported in the literature as well [26,30,43,44].…”

Section: Velocity Distributionsupporting

confidence: 90%

Stepped Spillways and Energy Dissipation: A Non-Uniform Step Length Approach

Ashoor

Riazi

2019

Applied Sciences

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“…Mohammad et al [37] used the VOF model and the turbulence models RNG and LES to simulate the interaction between air and water using stepped spillway models with a steep slope. Bai and Zhang [38] simulated a different type of stepped spillway called the V-type stepped spillway. They analyzed the pressure distribution by five different turbulence models and compared it with the physical values.…”

Section: LImentioning

confidence: 99%

Effect of Height and Geometry of Stepped Spillway on Inception Point Location

2019

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Air entrainment in a stepped spillway is very important to protect the spillway from cavitation damage. The inception point is the location where air starts entering the non-aerated flow zone. The inception point location depends on different parameters, such as the discharge, step height, and step shape. In this paper, various stepped spillways, including flat steps, pooled steps, and round steps with different step heights were numerically simulated using the volume of fluid and realizable k-ε models. The results indicate that the inception point location moves downwards with the increase of the discharge of the stepped spillways. The length of the non-aerated flow zone increases with the discharge. The inception point location moves downwards as the step height decreases and the step number increases at the same discharge. The inception point location of the round stepped spillway model is much closer to the spillway crest than that of the flat stepped spillway with the same number of steps. The inception point location of the pooled stepped spillway is closer to the spillway crest than that of the flat stepped spillway, but more downstream than that of the round stepped spillway.

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“…Performing CFD simulations is an effective tool to study complex flow problems [23][24][25][26]. Previous CFD studies [21,[27][28][29] reported the capability of the k − ε model in reproduction of the major hydraulic characteristics of the flows over stepped spillways. erefore, in the current study, this turbulence model by Launder and Spalding [30] is used to look into the spillway flow features with different step layouts.…”

Section: Numerical Modelmentioning

confidence: 99%

CFD Modelling of a Stepped Spillway with Various Step Layouts

Yang

2019

Mathematical Problems in Engineering

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A traditional stepped spillway is prone to cavitation risks. To improve its hydraulic behaviors, distorted step faces and pool weirs are devised. By numerical modelling, comparative studies are conducted to look into the flow features. The pressures on step surfaces of the unconventional layouts exhibit 3D distributions. Pool weirs are essential in increasing both the min. and max. pressure loads. Pressures on the downstream bed show a unique pattern for V- and inverted V-shaped models, with the extreme pressures at the sidewalls for the former and at the central plane for the latter. Symmetrical secondary flows are formed in V- and inverted V-shaped cases with different patterns. Distributions of turbulent kinetic energy suggest differences in flow motions in all cases. Furthermore, the relative energy loss of flat setups is ∼5.4% lower than that of the pooled ones with the same step face angle; inverting the face angle does not give rise to noticeable change. The results provide reference for relevant projects.

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Comparison of Different Turbulence Models for Numerical Simulation of Pressure Distribution in V-Shaped Stepped Spillway

Cited by 13 publications

References 17 publications

Stepped Spillways and Energy Dissipation: A Non-Uniform Step Length Approach

Stepped Spillways and Energy Dissipation: A Non-Uniform Step Length Approach

Effect of Height and Geometry of Stepped Spillway on Inception Point Location

CFD Modelling of a Stepped Spillway with Various Step Layouts

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