scholarly journals SPH MODEL TO SIMULATE MOVEMENT OF GRASS MEADOW OF POSIDONIA UNDER WAVES

2012 ◽  
Vol 1 (33) ◽  
pp. 56 ◽  
Author(s):  
Philippe Larroude ◽  
Thibault Oudart

The objective of this paper is to try a new approach to simulate the interactions between waves and algae. The chosen method is to simulate waves and plants through SPH (Smoothed Particle Hydrodynamics, SPH). In this model, the algae are defined as a solid that respects Hook's law, which is in direct interaction with the fluid part. Given the properties of this method especially in terms of computation time, the dimensions of the simulations are limited. A successful representation of the movement of algae under waves or/and current by SPH will permit the determination of coefficient of friction corresponding to a type of algae, that can be used in a different larger scale code.


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.



2017 ◽  
Vol 10 (2) ◽  
pp. 143-153 ◽  
Author(s):  
Maziar Gholami Korzani ◽  
Sergio A. Galindo-Torres ◽  
Alexander Scheuermann ◽  
David J. Williams


2020 ◽  
Vol 17 (10) ◽  
pp. 2050009
Author(s):  
Sisi Tan ◽  
Mingze Xu

Numerical modeling of whole blood still faces great challenges although significant progress has been achieved in recent decades, because of the large differences of physical and geometric properties among blood components, including red blood cells (RBCs), platelets (PLTs) and white blood cells (WBCs). In this work, we develop a three-dimensional (3D) smoothed particle hydrodynamics (SPH) model to study the whole blood in shear flow. The immersed boundary method (IBM) is used to deal with the interaction between the fluid and cells, which provides a possibility to model the RBCs, PLTs and WBCs simultaneously. The deformation of a small capsule, comparable to a PLT in size, is first examined to show the feasibility of SPH model for the PLTs’ behaviors. The motion of a single RBC in shear flow is then studied, and three typical modes, tank-treading, swinging and tumbling motions, are reproduced, which further confirm the reliability of the SPH model. After that, a simulation of the whole blood in shear flow is carried out, in which the margination trend is observed for both PLTs and WBC. This shows the capability of SPH model with IBM for the simulation of whole blood.





2019 ◽  
Vol 141 (7) ◽  
Author(s):  
Kai Gong ◽  
Songdong Shao ◽  
Hua Liu ◽  
Pengzhi Lin ◽  
Qinqin Gui

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.





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 7 (6) ◽  
pp. 614-620 ◽  
Author(s):  
Jingsi Wang ◽  
◽  
Keita Shimada ◽  
Masayoshi Mizutani ◽  
Tsunemoto Kuriyagawa

Hammering action plays a primary role in material removal in ultrasonic machining (USM). In the present study, Smoothed Particle Hydrodynamics (SPH) is used to simulate the hammering action of a single silicon carbide abrasive particle on a float glass workpiece, and the implications for crack initiation and propagation on the workpiece are discussed in detail. The adequacy of the SPH model is verified through an experiment that utilizes a stationary ultrasonic drilling machine. It is shown that the distribution and size of the cracks on the sample workpiece are well in agreement with the simulation results. The current study presents a new way to understand the material removal process of USM, which is extremely significant for the further improvement of the performance of USM techniques.



2019 ◽  
Vol 17 (09) ◽  
pp. 1950075
Author(s):  
Long Feng ◽  
Xiangwei Dong ◽  
Zengliang Li ◽  
Guirong Liu ◽  
Zhaocheng Sun

Abrasive waterjet is widely used for mass-cutting during coal mining or other mining process. Such a cutting process involves complex fluid–solid coupling, which require an effective method capable of simulating the large deformation and spalling of materials. This paper uses method of smoothed particle hydrodynamics (SPH) to establish a model to simulate the cutting process of coal seams by abrasive waterjets. In our SPH model, both fluid and solid are discretized with SPH particles. These particles are different in physical properties representing waterjet, abrasive particles and target materials. The waterjet is treated as viscous fluid and the coal (as a target material) is modeled as a brittle solid material. All these SPH particles of various medium are governed by the Navier–Stokes (NS) equations. Our established SPH model is then applied to study the efficiency of coal cutting using different waterjet formations. The results show that the cutting efficiency of the abrasive waterjet is higher than that of the standard waterjet. Our SPH model is capable of reveal the detailed interactions of the micro waterjet abrasive particles with the particles on the surface of coal. It enables the study on the mechanisms of coal seam breaking and cutting processes. It provides an effective computational tool for improving the efficiency of coal mining and of the development of new techniques for coal mining.



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