SPH Simulation of Hydraulic Jump on Corrugated Riverbeds

This paper presents a numerical study of the hydraulic jump on corrugated riverbed using the Smoothed Particle Hydrodynamics (SPH) method. By simulating an experimental benchmark example, the SPH model is demonstrated to predict the wave profile, velocity field, and energy dissipation rate of hydraulic jump with good accuracy. Using the validated SPH model, the dynamic evolvement of the hydraulic jump on corrugated riverbed is studied focusing on the vortex pattern, jump length, water depth after hydraulic jump, and energy dissipation rate. In addition, the influences of corrugation height and length on the characteristics of hydraulic jump are parametrically investigated.

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Study on the Best Depth of Stilling Basin with Shallow-Water Cushion

Water ◽

10.3390/w10121801 ◽

2018 ◽

Vol 10 (12) ◽

pp. 1801

Author(s):

Qiulin Li ◽

Lianxia Li ◽

Huasheng Liao

Keyword(s):

Energy Dissipation ◽

Shallow Water ◽

Froude Number ◽

Flow Regime ◽

Dissipation Rate ◽

Hydraulic Jump ◽

Energy Dissipation Rate ◽

Main Stream ◽

Stilling Basin ◽

Key Factor

The depth of the stilling basin with shallow-water cushion (SBSWC) is a key factor that affects the flow regime of hydraulic jump in the basin. However, the specific depth at which the water cushion is considered as ‘shallow’ has not been stated clearly by far, and only conceptual description is provided. Therefore, in order to define the best depth of SBSWC and its relationship between the Froude number at the inlet of the stilling basin, a large number of experiments were carried out to investigate SBSWC. First of all, 30 cases including five different Froude numbers and six depths were selected for which large eddy simulation (LES) was firstly verified by the experiments and then adopted to calculate the hydraulic characteristics in the stilling basin. Finally, three standards, based on the flow regime of hydraulic jump, the location of the main stream and the energy dissipation rate, were proposed to define the best depth of SBSWC. The three criteria are as follows: (1) a complete hydraulic jump occurs in the basin (2) the water cushion is about 1/10–1/3 deep of the stilling basin, and (3) the energy dissipation rate is more than 70% and the unit volume energy dissipation rate is as high as possible. It showed that the best depth ratio of SBSWC (depth to length ratio) was between 0.1 and 0.3 and it also indicated the best depth increased with the increase in Froude number. The results of the work are of significance to the design and optimizing of SBSWC.

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SPH Simulation of Wave Scattering by a Heaving Submerged Horizontal Plate

International Journal of Ocean and Coastal Engineering ◽

10.1142/s2529807018400043 ◽

2018 ◽

Vol 01 (02) ◽

pp. 1840004 ◽

Cited By ~ 2

Author(s):

Ming He ◽

Wanhai Xu ◽

Xifeng Gao ◽

Bing Ren

Keyword(s):

Wave Scattering ◽

Numerical Study ◽

Horizontal Plate ◽

Particle Hydrodynamics ◽

Smoothed Particle ◽

Submerged Horizontal Plate ◽

Wave Blocking ◽

Sph Simulation ◽

Wave Induced ◽

Blocking Mechanism

Liu et al. [Liu, C., Huang, Z. & Chen, W. [2017] “A numerical study of a submerged horizontal heaving plate as a breakwater,” J. Coast. Res.33(4), 917–930.] numerically studied the wave scattering by a heaving submerged horizontal plate (SHP) within the framework of the potential flow theory. They presented the excellent performance of the heaving SHP on wave blocking, because the radiated wave induced by the heave response of plate is likely to neutralize the transmitted wave. As a further study, the present work simulates the wave–heaving SHP interaction using the smoothed particle hydrodynamics, which is widely recognized as a powerful tool for computing complex viscous fluid dynamics. In this way, additional understanding on the wave blocking mechanism of the heaving SHP is contributed. The effect of submergence of plate on the wave and structural dynamics is also investigated. The results show that, under most submergence conditions, a heaving SHP breakwater is more effective than a fixed one. In terms of the limited cases in this research, 17% is proven to be the optimum ratio of submergence to water depth for the heaving SHP breakwater.

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SPH Simulation of High-Volume Rapid Landslides Triggered by Earthquakes Based on a Unified Constitutive Model. Part II: Solid–Liquid-Like Phase Transition and Flow-Like Landslides

International Journal of Computational Methods ◽

10.1142/s0219876218501499 ◽

2019 ◽

Vol 17 (04) ◽

pp. 1850149 ◽

Cited By ~ 2

Author(s):

Yangjuan Bao ◽

Yu Huang ◽

G. R. Liu ◽

Wei Zeng

Keyword(s):

Phase Transition ◽

Constitutive Model ◽

Slip Surface ◽

Solid Phase ◽

High Volume ◽

Particle Hydrodynamics ◽

Sph Model ◽

Smoothed Particle ◽

Sph Simulation ◽

Solid Liquid

High-volume fast-moving landslides undergo a solid–liquid-like phase transition. In this study we apply the smoothed particle hydrodynamics (SPH) method to simulate the solid–liquid-like phase transition in earthquake-induced landslides based on a unified constitutive model. The feasibility analysis is carried out from two aspects: the governing equations in SPH and the unified constitutive model. A sand-collapse experiment simulating the fluidization motion is performed to verify the SPH model. Strong similarities between the SPH results and the experimental results are observed, confirming that the motion of geo-materials in different states can be simulated by the unified constitutive model. The entire process of the Tangjiashan landslide is reproduced. The SPH simulation shows that during the initiation process, the sliding-mass velocity was low as the geo-materials were in solid state. As shown in Part I of this study, a continuous slip surface formed at about 15[Formula: see text]s. The sliding body gains speed as it enters the fluid state. About 50[Formula: see text]s later, the mass gradually stops moving, reaches a steady state and returns to a solid phase. Besides, the SPH simulation based on elastic–plastic model clearly shows the advantage of the proposed model.

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Numerical Study of Binary Trickle Flow of Liquid Iron and Molten Slag in Coke Bed by Smoothed Particle Hydrodynamics

Processes ◽

10.3390/pr8020221 ◽

2020 ◽

Vol 8 (2) ◽

pp. 221 ◽

Cited By ~ 2

Author(s):

Shungo Natsui ◽

Kazui Tonya ◽

Hiroshi Nogami ◽

Tatsuya Kikuchi ◽

Ryosuke O. Suzuki ◽

...

Keyword(s):

Liquid Iron ◽

Smoothed Particle Hydrodynamics ◽

Molten Slag ◽

Numerical Study ◽

Surface Force ◽

Attractive Force ◽

Iron Slag ◽

Particle Hydrodynamics ◽

Smoothed Particle ◽

Sph Simulation

In the bottom region of blast furnaces during the ironmaking process, the liquid iron and molten slag drip into the coke bed by the action of gravity. In this study, a practical multi-interfacial smoothed particle hydrodynamics (SPH) simulation is carried out to track the complex liquid transient dripping behavior involving two immiscible phases in the coke bed. Numerical simulations were performed for different conditions corresponding to different values of wettability force between molten slag and cokes. The predicted dripping velocity changes and interfacial shape were investigated. The relaxation of the surface force of liquid iron plays a significant role in the dripping rate; i.e., the molten slag on the cokes acts as a lubricant against liquid iron flow. If the attractive force between the coke and slag is smaller than the gravitational force, the slag then drops together with the liquid iron. When the attractive force between the coke and slag becomes dominant, the iron-slag interface will be preferentially detached. These results indicate that transient interface morphology is formed by the balance between the momentum of the melt and the force acting on each interface.

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A Novel Analytical Method for Evaluating the Characteristics of Hydraulic Jump at a Positive Step

Water ◽

10.3390/w13152005 ◽

2021 ◽

Vol 13 (15) ◽

pp. 2005

Author(s):

Milad Mohammadi ◽

Mohammad Nazari-Sharabian ◽

Moses Karakouzian

Keyword(s):

Experimental Data ◽

Energy Dissipation ◽

Dissipation Rate ◽

Hydraulic Jump ◽

Rectangular Channel ◽

Theoretical Models ◽

Energy Dissipation Rate ◽

Flow Depth ◽

Jump Length ◽

Positive Step

We present a new method to evaluate the hydraulic jump characteristics in a horizontal rectangular channel with a positive step. We considered the flow curvature effect and the free surface’s small rise at the A-type hydraulic jump’s end. First, we present a novel method to give jump length estimation based on the similarity of the jump and the turbulent wall-jet, considering the pressure gradient. Then, considering the jump as a curvilinear flow and using a one-dimensional momentum equation, we present an accurate expression for the conjugate flow depth regarding the initial Froude number and step height. Finally, we compute the jump’s energy dissipation rate. Compared to the theoretical models for conjugate flow depth in a hydraulic jump, the proposed equation in this study fit the experimental data better, even for high steps and large initial Froude numbers. However, for low Froude numbers (F1 < 5), the equation was less accurate in estimating the jump length. Regarding the jump’s energy dissipation rate, the results agreed well with the experimental data from previous investigations. However, it is noted that the increased energy dissipation rate dwindled in larger Froude numbers.

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Numerical Simulation of Non-Homogeneous Viscous Debris-Flows Based on the Smoothed Particle Hydrodynamics (SPH) Method

Water ◽

10.3390/w11112314 ◽

2019 ◽

Vol 11 (11) ◽

pp. 2314 ◽

Cited By ~ 4

Author(s):

Shu Wang ◽

Anping Shu ◽

Matteo Rubinato ◽

Mengyao Wang ◽

Jiping Qin

Keyword(s):

Debris Flow ◽

Water Content ◽

Smoothed Particle Hydrodynamics ◽

Debris Flows ◽

Sph Method ◽

Particle Hydrodynamics ◽

Sph Model ◽

Smoothed Particle ◽

The Impact ◽

Kinetic And Potential Energies

Non-homogeneous viscous debris flows are characterized by high density, impact force and destructiveness, and the complexity of the materials they are made of. This has always made these flows challenging to simulate numerically, and to reproduce experimentally debris flow processes. In this study, the formation-movement process of non-homogeneous debris flow under three different soil configurations was simulated numerically by modifying the formulation of collision, friction, and yield stresses for the existing Smoothed Particle Hydrodynamics (SPH) method. The results obtained by applying this modification to the SPH model clearly demonstrated that the configuration where fine and coarse particles are fully mixed, with no specific layering, produces more fluctuations and instability of the debris flow. The kinetic and potential energies of the fluctuating particles calculated for each scenario have been shown to be affected by the water content by focusing on small local areas. Therefore, this study provides a better understanding and new insights regarding intermittent debris flows, and explains the impact of the water content on their formation and movement processes.

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