Simulation of Angular Flow in a Shallow Basin Triggered by a Rotating Vertical Cylinder by SPH Method

2018 ◽  
Vol 881 ◽  
pp. 15-22
Author(s):  
Warniyati ◽  
Radianta Triatmadja ◽  
Nur Yuwono
Keyword(s):  
Numerical Model ◽  
Physical Model ◽  
Time Integration ◽  
Vertical Cylinder ◽  
Shear Velocity ◽  
Future Research ◽  
Sph Method ◽  
Virtual Particle ◽  
Real Particle ◽  
Particle Hydrodynamics

A simple numerical model has been generated for developing a code of Smoothed Particle Hydrodynamics (SPH) method. Those will be modified and used for future research. In this computational research domain is a square that consists of a real particle and virtual particle as the boundary treatment. In the initial condition, particle occupies a certain position. Circular flow has been generated by a rotating vertical cylinder to produce shear velocity to the real particle. The particles movement has been observed during time integration. A physical model has been constructed to compare the numerical model. The movement of real particles on the numerical model agrees with the movement of water particles on the physical model.

Failure mechanism of two-dimensional granular columns: Numerical simulation and experiments

2015 ◽  
Vol 37 (4) ◽  
pp. 239-250
Author(s):  
Nguyen Tien Cuong ◽  
Bui Hong Ha ◽  
Ryoichi Fukagawa
Keyword(s):  
Numerical Model ◽  
High Speed ◽  
Soil Mechanics ◽  
Granular Flows ◽  
Destruction Process ◽  
Sph Method ◽  
Deformation Problem ◽  
Particle Hydrodynamics ◽  
Calculation Results ◽  
Granular Column

In this article, two typical experiments for two types of destruction of granular column were performed by 2D soil model. High speed camera was used to record the movements of the destruction of the granular column. The images clearly showed the whole development of granular flows. The destruction process of the granular column in the two experiments is a big deformation problem of soil mechanics. To simulate the destruction process of the granular column, a model solving the problem of soil mechanics by Smoothed Particle Hydrodynamics (SPH) method was developed. The basic equations of problems of soil mechanics using the Drucker-Prager constitutive model were discretized using SPH method. The calculation results of the numerical model developed by us were compared with the experiment results obtained at the same time since the destruction of the granular column started. This was the first time by comparing and analyzing in details the characteristics of the process of destruction and developments of granular flows for the two typical types of destruction of granular column, it was shown that the numerical model describes quite accurately the characteristics of granular flows in both space and~time.

Geometrically nonlinear analysis of two-dimensional structures using an improved smoothed particle hydrodynamics method

2015 ◽  
Vol 32 (3) ◽  
pp. 779-805 ◽  
Author(s):  
Jun Lin ◽  
Hakim Naceur ◽  
Daniel Coutellier ◽  
Abdel Laksimi
Keyword(s):  
Nonlinear Analysis ◽  
Smoothed Particle Hydrodynamics ◽  
Time Integration ◽  
Geometrically Nonlinear ◽  
Sph Method ◽  
Geometrically Nonlinear Analysis ◽  
Content Type ◽  
Particle Hydrodynamics ◽  
Sph Model ◽  
Smoothed Particle

Purpose – The purpose of this paper is to present an efficient smoothed particle hydrodynamics (SPH) method particularly adapted for the geometrically nonlinear analysis of structures. Design/methodology/approach – In order to resolve the inconsistency phenomenon which systematically occurs in the standard SPH method at the domain’s boundaries of the studied structure, the classical kernel function and its spatial derivatives were modified by the use of Taylor series expansion. The well-known tensile instabilities inherent to the Eulerian SPH formulation were attenuated by the use of the Total Lagrangian Formulation (TLF). Findings – In order to demonstrate the effectiveness of the present improved SPH method, several numerical applications involving geometrically nonlinear behaviors were carried out using the explicit dynamics scheme for the time integration of the PDEs. Comparisons of the obtained results using the present SPH model with analytical reference solutions and with those obtained using ABAQUS finite element (FE) commercial software, show its good accuracy and robustness. Practical implications – An additional application including a multilayered composite structure and involving buckling and delamination was investigated using the present improved SPH model and the results are compared to the FE results, they confirmed both the efficiency and the accuracy of the proposed method. Originality/value – An efficient 2D-continuum SPH model for the geometrically nonlinear analysis of thin and thick structures is proposed. Contrarily to the classical SPH approaches, here the constitutive material relations are used to link naturally the stresses and strains. The Total Lagrangian approach is investigated to alleviate the tensile instabilities problem, allowing at the same time to avoid the updating procedure of the neighboring particles search and therefore reducing CPU usage. The proposed approach is valid for isotropic and multilayered composites structures undergoing large transformations. CPU time savings and better results with the new 2D-continuum SPH formulation compared to the classical continuum SPH. The explicit dynamic scheme was used for time integration allowing a fast resolution algorithm even for highly nonlinear problems.

Validation of SPH-FE Numerical Modeling of the Interaction between a High-Speed Water Jet and a PMMA Target by CEL Model and Experimental Study

2020 ◽  
Vol 21 (3-4) ◽  
pp. 227-238
Author(s):  
I. Ben Belgacem ◽  
L. Cheikh ◽  
E.M. Barhoumi ◽  
W. Khan ◽  
W. Ben Salem
Keyword(s):  
Numerical Simulation ◽  
Numerical Model ◽  
High Speed ◽  
Water Jet ◽  
Fe Method ◽  
Sph Method ◽  
Impact Surface ◽  
Particle Hydrodynamics ◽  
Spherical Head ◽  
The Impact

AbstractIn this paper, we present a numerical simulation of a round impacting jet using coupled Smoothed Particle Hydrodynamics (SPH) and Finite Element (FE) methods. Numerical results are compared with the results of another simulation carried out by the CEL (Coupled Eulerian-Lagrangian) method. A water jet with a spherical head was used at an initial speed of 570 m/s to impact a flat plate made of Polymethyl-Methacrylate (PMMA). To model the entire process, the SPH method was used to model the water jet and the FE method for the PMMA structure. The distribution of the pressure on the impact surface and the resulting deformation of the structure were discussed. A Numerical model was developed using ABAQUS/Explicit version 6.14. Results of the coupled SPH-FE simulation were further validated. It is demonstrated that the CEL method presents smoother curves compared to the SPH method. These comparisons serve not only to validate the numerical simulation but also to give guidance in formulating the SPH-FEM numerical model.

A Method Approaching Mirror Boundary Condition in SPH Simulation

2012 ◽  
Vol 516-517 ◽  
pp. 1043-1047
Author(s):  
Feng Jin ◽  
Chao Wan ◽  
Hu Ying Liu
Keyword(s):  
Boundary Condition ◽  
Smoothed Particle Hydrodynamics ◽  
Sph Method ◽  
Virtual Particle ◽  
Particle Hydrodynamics ◽  
Boundary Force ◽  
Smoothed Particle ◽  
Sph Simulation ◽  
Flow Particle ◽  
Good Agreement

A method approaching mirror boundary condition for smoothed particle hydrodynamics (SPH) method is presented. The virtual particle is generated through the nearest boundary particle of the flow particle. The operation is relatively simple and convenient and the applicability to the complexity boundaries can be markedly enhanced. The two dimensional non-linear sloshing is simulated with the new boundary condition. The results are in good agreement with the mirror boundary condition and the boundary force condition dada. It shows that this boundary condition can work well for SPH models.

scholarly journals Numerical Simulation of Crater Creating Process in Dynamic Replacement Method by Smooth Particle Hydrodynamics

2015 ◽  
Vol 36 (3) ◽  
pp. 3-8 ◽  
Author(s):  
Andrzej Danilewicz ◽  
Zbigniew Sikora
Keyword(s):  
Time Integration ◽  
Smoothing Function ◽  
Smooth Particle Hydrodynamics ◽  
Sph Method ◽  
Replacement Method ◽  
Dynamic Replacement ◽  
Boundary Treatment ◽  
Particle Hydrodynamics ◽  
Integration Techniques ◽  
Method Accuracy

Abstract A theoretical base of SPH method, including the governing equations, discussion of importance of the smoothing function length, contact formulation, boundary treatment and finally utilization in hydrocode simulations are presented. An application of SPH to a real case of large penetrations (crater creating) into the soil caused by falling mass in Dynamic Replacement Method is discussed. An influence of particles spacing on method accuracy is presented. An example calculated by LS-DYNA software is discussed. Chronological development of Smooth Particle Hydrodynamics is presented. Theoretical basics of SPH method stability and consistency in SPH formulation, artificial viscosity and boundary treatment are discussed. Time integration techniques with stability conditions, SPH+FEM coupling, constitutive equation and equation of state (EOS) are presented as well.

scholarly journals Upon Bulk Cavitation Appearing in Underwater Explosions

2017 ◽  
Vol 23 (3) ◽  
pp. 71-78
Author(s):  
Vasile Năstăsescu ◽  
Ghiță Bârsan
Keyword(s):  
Numerical Model ◽  
Numerical Modelling ◽  
Smoothed Particle Hydrodynamics ◽  
Underwater Explosion ◽  
Characteristic Parameters ◽  
Sph Method ◽  
Underwater Explosions ◽  
Particle Hydrodynamics ◽  
Smoothed Particle ◽  
Smoothed Particle Hydrodynamics Method

Abstract This paper presents some results of the author’s researching in connection with SPH (smoothed particle hydrodynamics) method and underwater explosion numerical modelling. All about cavitation fundamentals are considered known and about cavitation effects upon the structures. The authors, deeply preoccupied in using of SPH method, as well in modelling of the underwater explosion effects upon structures, had to take into consideration the bulk cavitation. A main issue in this study was the knowing of the bulk cavitation domain and its characteristic parameters. Such researching was possible to be successfully carried out, only by using of the SPH method. Finally, the paper presents the relations and the working way for knowing of the bulk cavitation domain and also a numerical model using SPH method is presented. The numerical example regarding shape and dimensions of the bulk cavitation is presented together putting in evidence of some parameters which can make damages upon a structure that is in the bulk cavitation area.

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

Water ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 2314 ◽  
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.

Numerical investigation of anguilliform locomotion by the SPH method

2019 ◽  
Vol 30 (1) ◽  
pp. 328-346 ◽  
Author(s):  
Amin Rahmat ◽  
Hossein Nasiri ◽  
Marjan Goodarzi ◽  
Ehsan Heidaryan
Keyword(s):  
Drag Coefficient ◽  
Numerical Investigation ◽  
Sph Method ◽  
Content Type ◽  
Aquatic Locomotion ◽  
Wide Range ◽  
Particle Hydrodynamics ◽  
Dummy Particles ◽  
Smoothed Particle ◽  
Sph Algorithm

Purpose This paper aims to introduce a numerical investigation of aquatic locomotion using the smoothed particle hydrodynamics (SPH) method. Design/methodology/approach To model this problem, a simple improved SPH algorithm is presented that can handle complex geometries using updatable dummy particles. The computational code is validated by solving the flow over a two-dimensional cylinder and comparing its drag coefficient for two different Reynolds numbers with those in the literature. Findings Additionally, the drag coefficient and vortices created behind the aquatic swimmer are quantitatively and qualitatively compared with available credential data. Afterward, the flow over an aquatic swimmer is simulated for a wide range of Reynolds and Strouhal numbers, as well as for the amplitude envelope. Moreover, comprehensive discussions on drag coefficient and vorticity patterns behind the aquatic are made. Originality/value It is found that by increasing both Reynolds and Strouhal numbers separately, the anguilliform motion approaches the self-propulsion condition; however, the vortices show different pattern with these increments.

scholarly journals Numerical modeling of reinforced concrete structures: static and dynamic analysis

2013 ◽  
Vol 66 (4) ◽  
pp. 425-430 ◽  
Author(s):  
Jorge Luis Palomino Tamayo ◽  
Armando Miguel Awruch ◽  
Inácio Benvegnu Morsch
Keyword(s):  
Reinforced Concrete ◽  
Numerical Model ◽  
Finite Elements ◽  
Dynamic Analysis ◽  
Time Integration ◽  
Great Accuracy ◽  
Constitutive Law ◽  
Published Data ◽  
Static And Dynamic Analysis ◽  
Plates And Shells

A numerical model using the Finite Element Method (FEM) for the nonlinear static and dynamic analysis of reinforced concrete (RC) beams, plates and shells is presented in this work. For this purpose, computer programs based on plasticity theory and with crack monitoring capabilities are developed. The static analysis of RC shells up to failure load is carried out using 9-node degenerated shell finite elements while 20-node brick finite elements are used for dynamic applications. The elasto-plastic constitutive law for concrete is coupled with a strain-rate sensitive model in order to take into account high loading rate effect when transient loading is intended. The implicit Newmark scheme with predictor and corrector phases is used for time integration of the nonlinear system of equations. In both cases, the steel reinforcement is considered to be smeared and represented by membrane finite elements. Various benchmark examples are solved with the present numerical model and comparisons with other published data are performed. For all examples, the path failure, collapse loads and failure mechanism is reproduced with great accuracy.

scholarly journals Progress in the Smoothed Particle Hydrodynamics Method to Simulate and Post-process Numerical Simulations of Annular Airblast Atomizers

2020 ◽  
Vol 105 (4) ◽  
pp. 1119-1147
Author(s):  
G. Chaussonnet ◽  
T. Dauch ◽  
M. Keller ◽  
M. Okraschevski ◽  
C. Ates ◽  
...  
Keyword(s):  
Smoothed Particle Hydrodynamics ◽  
Flux Ratio ◽  
Liquid Sheet ◽  
Sph Method ◽  
Post Process ◽  
Finite Time Lyapunov Exponent ◽  
Fragmentation Spectrum ◽  
Particle Hydrodynamics ◽  
Primary Breakup ◽  
Smoothed Particle

AbstractThis paper illustrates recent progresses in the development of the smoothed particle hydrodynamics (SPH) method to simulate and post-process liquid spray generation. The simulation of a generic annular airblast atomizer is presented, in which a liquid sheet is fragmented by two concentric counter swirling air streams. The accent is put on how the SPH method can bridge the gap between the CAD geometry of a nozzle and its characterization, in terms of spray characteristics and dynamics. In addition, the Lagrangian nature of the SPH method allows to extract additional data to give further insight in the spraying process. First, the sequential breakup events can be tracked from one large liquid blob to very fine stable droplets. This is herein called the tree of fragmentation. From this tree of fragmentation, abstract quantities can be drawn such as the breakup activity and the fragmentation spectrum. Second, the Lagrangian coherent structures in the turbulent flow can be determined easily with the finite-time Lyapunov exponent (FTLE). The extraction of the FTLE is particularly feasible in the SPH framework. Finally, it is pointed out that there is no universal and ultimate non-dimensional number that can characterize airblast primary breakup. Depending on the field of interest, a non-dimensional number (e.g. Weber number) might be more appropriate than another one (e.g. momentum flux ratio) to characterize the regime, and vice versa.

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