SPH Simulation of Hydrodynamic Forces on Subsea Pipelines

Author(s):  
Kourosh Abdolmaleki

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.

2013 ◽  
Vol 444-445 ◽  
pp. 889-893
Author(s):  
Qing Zhi Hou ◽  
Li Xiang Zhang ◽  
Arris S. Tijsseling ◽  
A.C.H. Kruisbrink

The free overfall can be used as a simple and accurate device for flow measurement in open channels. In the past, the solution to this problem was found mainly through simplified theoretical expressions or on the basis of experimental data. In this paper, using the meshless smoothed particle hydrodynamics (SPH) method, the free overfall in open channels with even and uneven bottom is investigated. For the even bottom case, subcritical, critical and supercritical flows are simulated. For the uneven bottom case, supercritical flows with different Froude numbers are considered. The free surface profiles are predicted and compared with theoretical and experimental solutions in literature and good agreements are obtained.


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.


2012 ◽  
Vol 516-517 ◽  
pp. 1043-1047
Author(s):  
Feng Jin ◽  
Chao Wan ◽  
Hu Ying Liu

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.


2021 ◽  
Vol 88 (3) ◽  
Author(s):  
Alberto Prieto-Arranz ◽  
Luis Ramírez ◽  
Iván Couceiro ◽  
Ignasi Colominas ◽  
Xesús Nogueira

AbstractIn this work, a new discretization of the source term of the shallow water equations with non-flat bottom geometry is proposed to obtain a well-balanced scheme. A Smoothed Particle Hydrodynamics Arbitrary Lagrangian-Eulerian formulation based on Riemann solvers is presented to solve the SWE. Moving-Least Squares approximations are used to compute high-order reconstructions of the numerical fluxes and, stability is achieved using the a posteriori MOOD paradigm. Several benchmark 1D and 2D numerical problems are considered to test and validate the properties and behavior of the presented schemes.


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.


Author(s):  
Amin Rahmat ◽  
Hossein Nasiri ◽  
Marjan Goodarzi ◽  
Ehsan Heidaryan

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.


2020 ◽  
Vol 105 (4) ◽  
pp. 1119-1147
Author(s):  
G. Chaussonnet ◽  
T. Dauch ◽  
M. Keller ◽  
M. Okraschevski ◽  
C. Ates ◽  
...  

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.


2022 ◽  
Author(s):  
Binghui Cui ◽  
Liaojun Zhang

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.


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