APPLICATION OF SMOOTHED PARTICLE HYDRODYNAMICS MODEL TO SIMULATE PIER SCOUR IN LABORATORY DAM BREAK FLOW

<p>Overtopping dam-break flow has great harm to the earthen embankments due to the hydraulic erosion. Some researchers have carried out relevant model experiments, but it is difficult to achieve the experimental conditions for the actual situation. The common numerical simulation is to express the scouring process through the empirical relationship, which obviously could not reflect the real scouring process. In this paper, a new overtopping erosion model using Smoothed Particle Hydrodynamics (SPH) is proposed. When the shear stress on the sediment SPH particle exceeds the critical stress, the erosion process begins. Then, when a sediment SPH particle is completely eroded, it will begin to move and is described as a non-Newtonian fluid. The un-incipient sediment particles are treated as boundary. This model is well validated with plane dike-breach experiment, and has also achieved a good agreement with erodible bed dam-break experiment.</p>

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Cylindrical Smoothed Particle Hydrodynamics Simulations of Water Entry

Journal of Fluids Engineering ◽

10.1115/1.4042369 ◽

2019 ◽

Vol 141 (7) ◽

Cited By ~ 6

Author(s):

Kai Gong ◽

Songdong Shao ◽

Hua Liu ◽

Pengzhi Lin ◽

Qinqin Gui

Keyword(s):

Smoothed Particle Hydrodynamics ◽

Three Dimensional ◽

Water Entry ◽

Surface Velocity ◽

Governing Equations ◽

Pressure Fields ◽

Particle Hydrodynamics ◽

Sph Model ◽

Smoothed Particle ◽

Dam Break Flow

This paper presents a smoothed particle hydrodynamics (SPH) modeling technique based on the cylindrical coordinates for axisymmetrical hydrodynamic applications, thus to avoid a full three-dimensional (3D) numerical scheme as required in the Cartesian coordinates. In this model, the governing equations are solved in an axisymmetric form and the SPH approximations are modified into a two-dimensional cylindrical space. The proposed SPH model is first validated by a dam-break flow induced by the collapse of a cylindrical column of water with different water height to semi-base ratios. Then, the model is used to two benchmark water entry problems, i.e., cylindrical disk and circular sphere entry. In both cases, the model results are favorably compared with the experimental data. The convergence of model is demonstrated by comparing with the different particle resolutions. Besides, the accuracy and efficiency of the present cylindrical SPH are also compared with a fully 3D SPH computation. Extensive discussions are made on the water surface, velocity, and pressure fields to demonstrate the robust modeling results of the cylindrical SPH.

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Pressure evaluation during dam break using weakly compressible SPH

EPJ Web of Conferences ◽

10.1051/epjconf/201921302030 ◽

2019 ◽

Vol 213 ◽

pp. 02030

Author(s):

Petr Jančík ◽

Tomáš Hyhlík

Keyword(s):

Experimental Data ◽

Smoothed Particle Hydrodynamics ◽

Two Dimensions ◽

Dam Break ◽

Kinematics And Dynamics ◽

Sph Method ◽

Weakly Compressible ◽

Particle Hydrodynamics ◽

Smoothed Particle ◽

The Impact

This paper presents a solution of a dam break problem in two dimensions obtained with smoothed particle hydrodynamics (SPH) method. The main focus is on pressure evaluation during the impact on the wall. The used numerical method and the way of pressure evaluation are described in detail. The numerical results of the kinematics and dynamics of the flow are compared with experimental data from the literature. The abilities and limitations of the used methods are discussed.

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Numerical Modeling of Debris Flows Induced by Dam-Break Using the Smoothed Particle Hydrodynamics (SPH) Method

Applied Sciences ◽

10.3390/app10082954 ◽

2020 ◽

Vol 10 (8) ◽

pp. 2954 ◽

Cited By ~ 3

Author(s):

Anping Shu ◽

Shu Wang ◽

Matteo Rubinato ◽

Mengyao Wang ◽

Jiping Qin ◽

...

Keyword(s):

Debris Flow ◽

Smoothed Particle Hydrodynamics ◽

Formation Process ◽

Debris Flows ◽

Dam Break ◽

Virtual Mass ◽

Sph Method ◽

Particle Hydrodynamics ◽

Smoothed Particle ◽

Number Of Particles

Dam-break flows may change into debris flows if certain conditions are satisfied, such as abundant loose material and steep slope. These debris flows are typically characterized by high density and can generate strong impact forces. Due to the complexity of the materials that they are made of, it has always been very challenging to numerically simulate these phenomena and accurately reproduce experimentally debris flows’ processes. Therefore, to fill this gap, the formation-movement processes of debris flows induced by dam-break were simulated numerically, modifying the existing smoothed particle hydrodynamics (SPH) method. By comparing the shape and the velocity of dam break debris flows under different configurations, it was found that when simulating the initiation process, the number of particles in the upstream section is overestimated while the number of particles in the downstream area is underestimated. Furthermore, the formation process of dam-break debris flow was simulated by three models which consider different combinations of the viscous force, the drag force and the virtual mass force. The method taking into account all these three kinds of interface forces produced the most accurate outcome for the numerical simulation of the formation process of dam-break debris flow. Finally, it was found that under different interface force models, the particle velocity distribution did not change significantly. However, the direction of the particle force changed, which is due to the fact that the SPH model considers generalized virtual mass forces, better replicating real case scenarios. The modalities of dam failures have significant impacts on the formation and development of debris flows. Therefore, the results of this study will help authorities to select safe sites for future rehabilitation and relocation projects and can also be used as an important basis for debris flow risk management. Future research will be necessary to understand more complex scenarios to investigate mechanisms of domino dam-failures and their effects on debris flows propagation.

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A 3D smoothed particle hydrodynamics model for erosional dam-break floods

International Journal of Computational Fluid Dynamics ◽

10.1080/10618562.2017.1422731 ◽

2017 ◽

Vol 31 (10) ◽

pp. 413-434 ◽

Cited By ~ 21

Author(s):

Andrea Amicarelli ◽

Bozhana Kocak ◽

Stefano Sibilla ◽

Jürgen Grabe

Keyword(s):

Smoothed Particle Hydrodynamics ◽

Dam Break ◽

Particle Hydrodynamics ◽

Smoothed Particle

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Experimental and SPH studies of reciprocal wet-bed dam-break flow over obstacles

International Journal of Modern Physics C ◽

10.1142/s0129183121500984 ◽

2021 ◽

pp. 2150098

Author(s):

Armin Ansari ◽

Ehsan Khavasi ◽

Jafar Ghazanfarian

Keyword(s):

Surface Deformation ◽

Three Dimensional ◽

Flow Characteristics ◽

Dam Break ◽

Experimental Results ◽

Mesh Free ◽

Particle Hydrodynamics ◽

Smoothed Particle ◽

Dam Break Flow ◽

Velocity Effect

Different permutations of the single and the two-fold dam-break flow have been investigated using the mesh-free smoothed-particle hydrodynamics and the experimental setup. The free-surface deformation in the case with the wet bed for five different downstream water heights has been investigated and respective numerical and experimental results were presented. The results demonstrate that the increase of the water height over the wet bed leads to the reduction of the flow front velocity. Effect of considering or omitting the dam gate during the numerical simulation has also been examined, which proves that the simulations including the dam gate show improved agreement with the experimental results. Influence of the three-dimensional cubic, triangular, circular and square cylindrical obstacles and their position on flow characteristics has been investigated. As the distance between the triangular obstacle and the gate increases, a bore is created at the position closer to the top of the triangle. In addition, it is found that larger force is exerted on the circular cylinder in comparison to the square cylinder.

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