scholarly journals GIS-Based Three-Dimensional SPH Simulation for the 11 April 2018 Yabakei Landslide at Oita Nakatsu, Japan

Water ◽  
2021 ◽  
Vol 13 (21) ◽  
pp. 3012
Author(s):  
Zheng Han ◽  
Fan Yang ◽  
Yange Li ◽  
Jie Dou ◽  
Ningsheng Chen ◽  
...  
Keyword(s):  
Dynamic Process ◽  
Residential Buildings ◽  
Three Dimensional ◽  
Field Investigation ◽  
Sph Method ◽  
Landslide Event ◽  
Gis Data ◽  
Particle Hydrodynamics ◽  
Sph Simulation ◽  
Event Based

Landslides are usually triggered by strong earthquakes, heavy rainfalls, or intensive human activities in common wisdom. However, an unexpected landslide occurred in the Yabakei area, Nakatsu, Oita, Japan, at the pre-dawn hour 3:50 a.m. on 11 April 2018, without any accompanying rainfall and earthquake records during the event. This catastrophic landslide was 200 m in width, 110 m in height, and 60,000 m3 in mass volume, damaging four residential buildings with fatalities of six residents at the landslide toe. Field investigation was conducted immediately to identify geological setting, hydrological condition, and landslide geomorphological characteristics. Key findings speculate that infiltration of groundwater stored in the internal fractures led to the swelling and breaking of illite and askanite in the weathered sediment rocks, resulting in the failure of the Yabakei landslide. To reproduce and explore the dynamic process of this landslide event, based on spatial GIS data, we applied the proposed three-dimensional, Herschel-Bulkley-Papanastasiou rheology model-based smooth particle hydrodynamics (HBP-SPH) method to simulate the landslide dynamic process. Buildings in the landslide area are covered by a set of surfaced cells (SC) to analyze the mass impact on the residential buildings. Results showed good accordance between observation and simulation by the proposed SC-HBP-SPH method. The landslide impact force to the residential buildings could be up to 4224.89 kN, as indicated by the simulation.

scholarly journals Application of Smoothed Particle Hydrodynamics (SPH) for the Simulation of Flow-like Landslides on 3D Terrains

2022 ◽  
Author(s):  
Binghui Cui ◽  
Liaojun Zhang
Keyword(s):  
Risk Assessment ◽  
Smoothed Particle Hydrodynamics ◽  
Disaster Mitigation ◽  
Sph Method ◽  
Landslide Event ◽  
Particle Hydrodynamics ◽  
Smoothed Particle ◽  
Simulation Results ◽  
Mitigation Design ◽  
The Impact

Abstract Flow-type landslide is one type of landslide that generally exhibits characteristics of high flow velocities, long jump distances, and poor predictability. Simulation of it facilitates propagation analysis and provides solutions for risk assessment and mitigation design. The smoothed particle hydrodynamics (SPH) method has been successfully applied to the simulation of two-dimensional (2D) and three-dimensional (3D) flow-like landslides. However, the influence of boundary resistance on the whole process of landslide failure is rarely discussed. In this study, a boundary algorithm considering the friction is proposed, and integrated into the boundary condition of the SPH method, and its accuracy is verified. Moreover, the Navier-Stokes equation combined with the non-Newtonian fluid rheology model was utilized to solve the dynamic behavior of the flow-like landslide. To verify its performance, the Shuicheng landslide event, which occurred in Guizhou, China, was taken as a case study. In the 2D simulation, a sensitivity analysis was conducted, and the results showed that the shearing strength parameters have more influence on the computation accuracy in comparison with the coefficient of viscosity. Afterwards, the dynamic characteristics of the landslide, such as the velocity and the impact area, were analyzed in the 3D simulation. The simulation results are in good agreement with the field investigations. The simulation results demonstrate that the SPH method performs well in reproducing the landslide process, and facilitates the analysis of landslide characteristics as well as the affected areas, which provides a scientific basis for conducting the risk assessment and disaster mitigation design.

scholarly journals A Study on Stable Regularized Moving Least-Squares Interpolation and Coupled with SPH Method

2020 ◽  
Vol 2020 ◽  
pp. 1-28
Author(s):  
Hua Jiang ◽  
Yunsai Chen ◽  
Xing Zheng ◽  
Shanqin Jin ◽  
Qingwei Ma
Keyword(s):  
Least Squares ◽  
Numerical Solutions ◽  
Kernel Functions ◽  
Moving Least Squares ◽  
Sph Method ◽  
Particle Distributions ◽  
Particle Hydrodynamics ◽  
Support Domain ◽  
Accuracy Result ◽  
Sph Simulation

The smoothed particle hydrodynamics (SPH) method has been popularly applied in various fields, including astrodynamics, thermodynamics, aerodynamics, and hydrodynamics. Generally, a high-precision interpolation is required to calculate the particle physical attributes and their derivatives for the boundary treatment and postproceeding in the SPH simulation. However, as a result of the truncation of kernel function support domain and irregular particle distribution, the interpolation using conventional SPH interpolation experiences low accuracy for the particles near the boundary and free surface. To overcome this drawback, stable regularized moving least-squares (SRMLS) method was introduced for interpolation in SPH. The surface fitting studies were performed with a variety of polyline bases, spatial resolutions, particle distributions, kernel functions, and support domain sizes. Numerical solutions were compared with the results using moving least-squares (MLS) and three SPH methods, including CSPH, K2SPH, and KGFSPH, and it was found that SRMLS not only has nonsingular moment matrix, but also obtains high-accuracy result. Finally, the capability of the algorithm coupled with SRMLS and SPH was illustrated and assessed through several numerical tests.

scholarly journals Star–disc alignment in the protoplanetary discs: SPH simulation of the collapse of turbulent molecular cloud cores

2020 ◽  
Vol 492 (4) ◽  
pp. 5641-5654 ◽  
Author(s):  
Daisuke Takaishi ◽  
Yusuke Tsukamoto ◽  
Yasushi Suto
Keyword(s):  
Time Scale ◽  
Molecular Cloud ◽  
Three Dimensional ◽  
Gravitational Energy ◽  
Circumstellar Envelope ◽  
Rotation Axes ◽  
Particle Hydrodynamics ◽  
Disc Rotation ◽  
Cloud Cores ◽  
Sph Simulation

ABSTRACT We perform a series of three-dimensional smoothed particle hydrodynamics (SPH) simulations to study the evolution of the angle between the protostellar spin and the protoplanetary disc rotation axes (the star–disc angle ψsd) in turbulent molecular cloud cores. While ψsd at the protostar formation epoch exhibits broad distribution up to ∼130°, ψsd decreases (≲ 20°) in a time-scale of ∼104 yr. This time-scale of the star–disc alignment, talignment, corresponds basically to the mass doubling time of the central protostar, in which the protostar forgets its initial spin direction due to the mass accretion from the disc. Values of ψsd both at t = 102 yr and t = 105 yr after the protostar formation are independent of the ratios of thermal and turbulent energies to gravitational energy of the initial cloud cores: α = Ethermal/|Egravity| and γturb = Eturbulence/|Egravity|. We also find that a warped disc is possibly formed by the turbulent accretion flow from the circumstellar envelope.

A Three-dimensional SPH Simulation of Iceberg Calving generated Waves

2021 ◽  
Author(s):  
Chao Hu ◽  
Xiao-liang Wang ◽  
Qing-quan Liu
Keyword(s):  
Large Scale ◽  
Three Dimensional ◽  
Particle Hydrodynamics ◽  
Flow Field Characteristics ◽  
Smoothed Particle ◽  
Iceberg Calving ◽  
Simulation Results ◽  
Sph Simulation ◽  
The Waves ◽  
Good Agreement

<p>The calving of large-scale icebergs into the sea can generate a local tsunami that may threaten coastal communities or passing ships. A three-dimensional smoothed particle hydrodynamics model of rigid-body–fluid system is established to simulate the spatial wave generated by calving iceberg. The model is tested with simulated waves induced by a cube iceberg fall into the water body. Good agreement is obtained between simulation results and experimental data. The generation and evolution processes, and the near flow-field characteristics of the waves are analyzed. The simulation results show that waves generated in iceberg calving can generate not only a huge leading wave but also notable tailing waves. The initial propagation direction of the leading wave is determined by iceberg geometry, but as the leading wave propagates away, the water level displacement gradually develops into a semicircle wavefront which is irrelevant to iceberg geometry.</p>

scholarly journals Welding Window: Comparison of Deribas’ and Wittman’s Approaches and SPH Simulation Results

Metals ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 1323 ◽  
Author(s):  
Yulia Yu. Émurlaeva ◽  
Ivan A. Bataev ◽  
Qiang Zhou ◽  
Daria V. Lazurenko ◽  
Ivan V. Ivanov ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
High Velocity ◽  
High Velocity Impact ◽  
Sph Method ◽  
Velocity Impact ◽  
Particle Hydrodynamics ◽  
Smoothed Particle ◽  
Impact Welding ◽  
Simulation Results ◽  
Sph Simulation

A welding window is one of the key concepts used to select optimal regimes for high-velocity impact welding. In a number of recent studies, the method of smoothed particle hydrodynamics (SPH) was used to find the welding window. In this paper, an attempt is made to compare the results of SPH simulation and classical approaches to find the boundaries of a welding window. The experimental data on the welding of 6061-T6 alloy obtained by Wittman were used to verify the simulation results. Numerical simulation of high-velocity impact accompanied by deformation and heating was carried out by the SPH method in Ansys Autodyn software. To analyze the cooling process, the heat equation was solved using the finite difference method. Numerical simulation reproduced most of the explosion welding phenomena, in particular, the formation of waves, vortices, and jets. The left, right, and lower boundaries found using numerical simulations were in good agreement with those found using Wittman’s and Deribas’s approaches. At the same time, significant differences were found in the position of the upper limit. The results of this study improve understanding of the mechanism of joint formation during high-velocity impact welding.

SPH Simulation of Hydrodynamic Forces on Subsea Pipelines

2011 ◽  
Author(s):  
Kourosh Abdolmaleki
Keyword(s):  
Hydrodynamic Forces ◽  
Forced Oscillations ◽  
Sph Method ◽  
Flat Bottom ◽  
Extreme Load ◽  
Particle Hydrodynamics ◽  
Smoothed Particle ◽  
Sph Simulation ◽  
Subsea Pipelines ◽  
Supercritical Flows

Hydrodynamic forces on subsea pipelines are simulated using Smoothed Particle Hydrodynamics (SPH) method. The objective is to assess the suitability of this method for common sub-sea engineering problems. The standard SPH formulation is used for simulation of cases with high KC and Re numbers, where the flow becomes turbulent with laminar or partially turbulent boundary layer. The numerical model includes a pipe section with smooth surface resting on a flat bottom. The pipe is exposed to various combinations of regular waves and current. The current is modelled as a steady flow of fluid particles and the waves are represented by forced oscillations of the pipe at defined frequencies and amplitudes. The selected KC and Re numbers produces subcritical and supercritical flows, which simulate extreme load cases on pipelines. In subcritical flows, the estimated forces on the pipeline agree well with experimental data. In supercritical flows with high KC and Re values, a relatively finer particle resolution is required in order to capture multiple harmonics of oscillating lift force. In conclusion, the SPH method could satisfactorily predict hydrodynamic forces on pipelines for the cases investigated.

scholarly journals 3D Numerical Simulation of Landslides for the Full High Waste Dump Using SPH Method

2021 ◽  
Vol 2021 ◽  
pp. 1-16
Author(s):  
Chunhui Cao ◽  
Jili Feng ◽  
Zhigang Tao
Keyword(s):  
Dynamic Process ◽  
Failure Process ◽  
Vertical Direction ◽  
Waste Dump ◽  
Sph Method ◽  
Particle Hydrodynamics ◽  
Sph Model ◽  
Smoothed Particle ◽  
And Control ◽  
Sliding Distance

Waste dump that is generally composed of a large number of loose geotechnical materials is prone to landslides under external loads. In this work, the smoothed particle hydrodynamics (SPH) method combined with the Mohr–Coulomb model is used to study the dynamic characteristics of the landslides that occurred in the waste dump during the failure process. A benchmark test is firstly conducted to verify the effectiveness of the SPH model. Then, taking the Nanfen full high waste dump with a vertical drop of 300 m in Benxi City, China, as an example, the most dangerous section is selected to establish the SPH numerical model for the waste dump landslides, and the overall dynamic process of the landslides is simulated. The simulation results show that the particles in the middle and upper of the slope have larger potential energy, and their sliding distance is larger. On the contrary, the sliding distance of particles in the lower of the slope is smaller. The particles' sliding distance decreases as the depth increases in the vertical direction of both shoulder and middle of the slope. The particles undergo a process of first acceleration and then deceleration. The sliding distance is in good agreement with the field survey result, and the landslides profile is basically consistent with the actual one. The sensitivity analysis of different particle numbers shows that the number of particles has little effect on the numerical results. The SPH method can vividly reproduce the dynamic process of the landslides in the full high waste dump. The evaluation of the sliding characteristics and risk impact range can provide the key parameters and basis for the prevention and control of the landslides in the full high waste dump and ensure the safety of the mine life cycle.

Numerical simulation of dissolution of solid particles in fluid flow using the SPH method

2019 ◽  
Vol 30 (1) ◽  
pp. 290-307 ◽  
Author(s):  
Amin Rahmat ◽  
Mostafa Barigou ◽  
Alessio Alexiadis
Keyword(s):  
Three Dimensional ◽  
Solid Particles ◽  
Sph Method ◽  
Content Type ◽  
Wide Range ◽  
Particle Hydrodynamics ◽  
Schmidt Numbers ◽  
Smoothed Particle ◽  
Diffusion Mass ◽  
Mass Transport Equation

Purpose The purpose of this paper is to numerically study the dissolution of solid particles using the smoothed particle hydrodynamics (SPH) method. Design/methodology/approach To implement dissolution, an advection–diffusion mass transport equation is solved over computational particles. Subsequently, these particles disintegrate from the solute when their concentration falls below a certain threshold. Findings It is shown that the implementation of dissolution is in good agreement with available data in the literature. The dissolution of solid particles is studied for a wide range of Reynolds and Schmidt numbers. Two-dimensional (2D) results are compared with three-dimensional (3D) cases to identify where 2D results are accurate for modelling 3D dissolution phenomena. Originality/value The present numerical model is capable of addressing related problems in pharmaceutical, biochemical, food processing and detergent industries.

The Theories and Application of Numerical Simulation with Smoothed Particle Hydrodynamics Method

2012 ◽  
Vol 531-532 ◽  
pp. 695-698
Author(s):  
Hui Lin Zhou ◽  
Hui Yong Yu ◽  
Ming Hua Pang
Keyword(s):  
Smoothed Particle Hydrodynamics ◽  
Three Dimensional ◽  
Hypervelocity Impact ◽  
Particle Model ◽  
Sph Method ◽  
Particle Hydrodynamics ◽  
Smoothed Particle ◽  
Impact Problems ◽  
Numerical Calculation Method ◽  
The Impact

The Smoothed Particle Hydrodynamics (SPH) method is a very important method to resolve hypervelocity problems and the basic theory of SPH method is introduced here. Then the three dimensional hypervelocity impact problems are simulated by using the model of chair. The results of SPH analysis show that (SPH) method is a numerical calculation method to resolve hypervelocity problems without mesh model but the particle model must be getting to calculate and the program code is less than other method. By analysis the results of the simulation is reasonable and very similar to the test result. It can be concluded that the advantages of SPH demonstrated make it a good and an ideal method to simulate the impact problem and other problems.

scholarly journals Numerical Investigation on the Kinetic Characteristics of the Yigong Debris Flow in Tibet, China

Water ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1076
Author(s):  
Zili Dai ◽  
Kai Xu ◽  
Fawu Wang ◽  
Hufeng Yang ◽  
Shiwei Qin
Keyword(s):  
Debris Flow ◽  
Three Dimensional ◽  
Field Investigation ◽  
Kinetic Characteristics ◽  
Runout Distance ◽  
Barrier Lake ◽  
Particle Hydrodynamics ◽  
Sph Model ◽  
Simulation Results ◽  
Three Dimensional Models

To analyze the kinetic characteristics of a debris flow that occurred on 9 April 2000 in Tibet, China, a meshfree numerical method named smoothed particle hydrodynamics (SPH) is introduced, and two-dimensional and three-dimensional models are established in this work. Based on the numerical simulation, the motion process of this debris flow is reproduced, and the kinetic characteristics are analyzed combining with the field investigation data. In the kinetic analysis, the flow velocity, runout distance, deposition, and energy features are discussed. Simulation results show that the debris flow mass undergoes an acceleration stage after failure, then the kinetic energy gradually dissipates due to the friction and collision during debris flow propagation. Finally, the debris flow mass blocks the Yigong river and forms a huge dam and an extensive barrier lake. The peak velocity is calculated to be about 100 m/s, and the runout distance is approximately 8000 m. The simulation results basically match the data measured in field, thus verifying the good performance of the presented SPH model. This approach can predict hazardous areas and estimate the hazard intensity of catastrophic debris flow.

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