SPH model for the simulation of lava-buildings interactions

Author(s):  
Vito Zago ◽  
Giuseppe Bilotta ◽  
Annalisa Cappello ◽  
Robert Dalrymple ◽  
Luigi Fortuna ◽  
...  

<p>Numerical simulation is a fundamental aspect of modern volcanology, providing tools for the forecasting of lava flows behavior, so as to assist in the design of mitigation actions for volcanic risk. In addition to the prediction of the emplacement topology, numerical simulation can be useful to study the possible outcomes of the interaction between a lava flow and a building. This kind of information can help to estimate the vulnerability of buildings so as to produce more accurate risk evaluations. Smoothed Particle Hydrodynamics (SPH) is a particle-based numerical method, particularly suited for the simulation of fluids with a high level of complexity, that can intrinsically deal with all of the physical properties of lava. GPUSPH is a simulation engine based on the SPH method that has been developed in order to take into account the challenging aspects of lava simulations and has been successfully applied to the simulation of lava-related benchmark tests. Here we use the SPH method, coupled within the framework of GPUSPH with a rigid body mechanics solver provided by the Project Chrono engine, for the realistic study of lava-buildings interaction. The resulting coupled model is able to simulate masonry with a brick-level accurate description, providing insights on any damages happening to the structure. We will show the simulation of a lava flow interacting with an elementary masonry piece, where a total collapse of the structure is induced by the action of the lava.</p>

2013 ◽  
Vol 760-762 ◽  
pp. 2188-2193
Author(s):  
Wen Hua Chu ◽  
Aman Zhang ◽  
Xiong Liang Yao

There are some extreme conditions in the process of metallic jet penetrating the explosive reaction armor (ERA), such as high instantaneity, large deformation, et al. Based on the smoothed particle hydrodynamics (SPH) method, the generalized density approximate formula is proposed and the Held criterion is introduced. Then the numerical SPH model of metallic jet penetrating the explosive reaction armor is built to study its protection mechanics. The calculation result meets well with the theoretical value. The influences of some parameters, such as thickness of plate and attacking angle, on the protecting effect of explosive reaction armor are analyzed, aiming at providing references for the related engineering application.


Water ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 2314 ◽  
Author(s):  
Shu Wang ◽  
Anping Shu ◽  
Matteo Rubinato ◽  
Mengyao Wang ◽  
Jiping Qin

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.


2011 ◽  
Vol 211-212 ◽  
pp. 1147-1151
Author(s):  
A Fang Jin ◽  
Zhi Chun Yang ◽  
Mamtimin Gheni

Smoothed particle hydrodynamics (SPH) method is used to simulate the lift-off phenomenon of sand particles in the air flow. Whether the sand particles make any form of movement in the air flow, firstly, they always jump into the air from a standstill condition, so it is helpfull to understand the saltation mechanism of sand particles. Because the computitional region is discreted into particles in the SPH method, the movement of each particle can represent the machnical behavior of sand particles if the particle dispersion has the same characteristic with the sand particles. The foundmental theory of SPH method and its key elements are reviewed in detail, such as the kernel function, the choice of smoothing length and their influence on the numerical simulation results.In this study a numerical simulation model of wind-blown sand two-phase flow using SPH model is proposed and then the model is discreted to simulate the take-off process of sand particles with adquate boundary conditions. Simulation results show that the proposed model can be used to simulate the dynamic characteristics of sand particles in lift-off.


2018 ◽  
Vol 16 (02) ◽  
pp. 1846008
Author(s):  
X. J. Ma ◽  
M. Geni ◽  
A. F. Jin

Based on the fundamental theory of smoothed-particle hydrodynamics (SPH), a feasible algorithm for fluid–solid coupling on interface is applied to describe the dynamic behavior of fluid and solid by utilizing continuum mechanics governing equations. Numerical simulation is conducted based on the proposed SPH model and the fluid–solid interface coupling algorithm, and good agreement is observed with the experiment results. It is shown in the results that the present SPH model is able to effectively and accurately simulate the free-surface flow of fluid, deformation of the elastic solid and the fluid–solid impacting.


Author(s):  
Sohaib Rashid Sulaiman Alahmed ◽  
Qingping Zou

A Smoothed Particle Hydrodynamics (SPH) method is used to investigate the flood characteristics occurring in an idealized city with two different building layouts: aligned layout and 22.5o skewed layout with respect to the direction of the incoming flow. The model results show that the water elevation is higher for the skewed city layout than that for the aligned city layout. The force due to the flood impact on the majority of buildings tend to be higher for the former than that for the latter. The complex flow features including a hydraulic jump during the flooding event are well captured by the SPH model.


2013 ◽  
Vol 1 (3) ◽  
pp. 2831-2857
Author(s):  
M. H. Dao ◽  
H. Xu ◽  
E. S. Chan ◽  
P. Tkalich

Abstract. Accurate predictions of wave run-up and run-down are important for coastal impact assessment of relatively long waves such as tsunami or storm waves. Wave run-up is, however, a complex process involving nonlinear build-up of the wave front, intensive wave breaking and strong turbulent flow, making the numerical approximation challenging. Recent advanced modeling methodologies could help to overcome these numerical challenges. For a demonstration, we study run-up of non-breaking and breaking solitary waves on vertical wall using two methods, the enhanced Smoothed Particle Hydrodynamics (SPH) method and the traditional non-breaking nonlinear model Tunami-N2. The Tunami-N2 model fails to capture the evolution of steep waves at the proximity of breaking that observed in the experiments. Whereas, the SPH method successfully simulate the wave propagation, breaking, impact on structure and the reform and breaking processes of wave run-down. The study also indicates that inadequate approximation of the wave breaking could lead to significant under-predictions of wave height and impact pressure on structures. The SPH model shows potential applications for accurate impact assessments of wave run-up onto coastal structures.


Metals ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 1323 ◽  
Author(s):  
Yulia Yu. Émurlaeva ◽  
Ivan A. Bataev ◽  
Qiang Zhou ◽  
Daria V. Lazurenko ◽  
Ivan V. Ivanov ◽  
...  

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.


2017 ◽  
Vol 14 (04) ◽  
pp. 1750039 ◽  
Author(s):  
Zili Dai ◽  
Huilong Ren ◽  
Xiaoying Zhuang ◽  
Timon Rabczuk

In the standard smoothed particle hydrodynamics (SPH) method, the interaction between two particles might be not pairwise when the support domain varies, which can result in a reduction of accuracy. To deal with this problem, a modified SPH approach is presented in this paper. First of all, a Lagrangian kernel is introduced to eliminate spurious distortions of the domain of material stability, and the gradient is corrected by a linear transformation so that linear completeness is satisfied. Then, concepts of support and dual-support are defined to deal with the unbalanced interactions between the particles with different support domains. Several benchmark problems in one, two and three dimensions are tested to verify the accuracy of the modified SPH model and highlight its advantages over the standard SPH method through comparisons.


2014 ◽  
Vol 553 ◽  
pp. 168-173 ◽  
Author(s):  
Maziar Gholami Korzani ◽  
Sergio Andres Galindo-Torres ◽  
David Williams ◽  
Alexander Scheuermann

The study concerns the application of the smoothed particle hydrodynamics (SPH) method within computational fluid dynamics. In the present study, a tank discharge with a falling head is investigated. Water is modelled as a viscous fluid with weak compressibility. An enhanced treatment of the solid boundaries is used within the two-dimensional SPH scheme. The boundaries are represented by a special set of SPH particles that differ from the ones representing the fluid by being immovable, preventing the fluid from leaving the container. Particles with different colors are used to illustrate the sequence of the empting the tank as well as the velocity vectors to show stream lines. A code is developed using C++ to solve all equations explicitly by use of a Verlet algorithm. Results are compared to an analytical solution, and a good agreement is achieved.


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