Simulation of Dynamic Coupling Between Waves and a Free-Floating Rectangular Box by Smoothed Particle Hydrodynamics

Author(s):  
Ming He ◽  
Bing Ren ◽  
Feng Jiang ◽  
Chunli Ma

An implementation of the smoothed particle hydrodynamics (SPH) method is presented to solve dynamic coupling between waves and a free-floating rectangular box. A 2D numerical wave tank (NWT) is established in this paper. Governing equations of weakly compressible smoothed particle hydrodynamics (WCSPH) are modified by CSPM and approximately Riemann solver. Boundaries of the NWT and the floating box are built with dynamic boundary particles (DBPs) described by Dalrymple. An active absorbing wavemaker is arranged at the upstream boundary of the NWT and an artificial damping layer is set on the other side. A comparison between SPH result and boundary element method (BEM) solution of wave forces on a fixed rectangular box is conducted to validate the numerical model. The interaction between waves and a floating box is simulated using the present model, and wave forces on the floating box and its motion responses under wave action are analysed.

2019 ◽  
Vol 213 ◽  
pp. 02030
Author(s):  
Petr Jančík ◽  
Tomáš Hyhlík

This paper presents a solution of a dam break problem in two dimensions obtained with smoothed particle hydrodynamics (SPH) method. The main focus is on pressure evaluation during the impact on the wall. The used numerical method and the way of pressure evaluation are described in detail. The numerical results of the kinematics and dynamics of the flow are compared with experimental data from the literature. The abilities and limitations of the used methods are discussed.


Author(s):  
Steven J. Lind ◽  
Benedict D. Rogers ◽  
Peter K. Stansby

This paper presents a review of the progress of smoothed particle hydrodynamics (SPH) towards high-order converged simulations. As a mesh-free Lagrangian method suitable for complex flows with interfaces and multiple phases, SPH has developed considerably in the past decade. While original applications were in astrophysics, early engineering applications showed the versatility and robustness of the method without emphasis on accuracy and convergence. The early method was of weakly compressible form resulting in noisy pressures due to spurious pressure waves. This was effectively removed in the incompressible (divergence-free) form which followed; since then the weakly compressible form has been advanced, reducing pressure noise. Now numerical convergence studies are standard. While the method is computationally demanding on conventional processors, it is well suited to parallel processing on massively parallel computing and graphics processing units. Applications are diverse and encompass wave–structure interaction, geophysical flows due to landslides, nuclear sludge flows, welding, gearbox flows and many others. In the state of the art, convergence is typically between the first- and second-order theoretical limits. Recent advances are improving convergence to fourth order (and higher) and these will also be outlined. This can be necessary to resolve multi-scale aspects of turbulent flow.


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.


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.


2016 ◽  
Vol 846 ◽  
pp. 73-78 ◽  
Author(s):  
Maziar Gholami Korzani ◽  
S. Galindo Torres ◽  
Alexander Scheuermann ◽  
David J. Williams

The study concerns the application of the Smoothed Particle Hydrodynamics (SPH) method within the computational fluid dynamics (CFD). In the present study, some classical problems – the Poiseuille flow, the Hagen-Poiseuille flow, and the Couette flow – with the analytical solutions were investigated to verify a newly developed code of SPH. The code used for solving these problems, is an entirely parallel SPH solver in 3D and has been developed by the authors. Fluid was modelled as a viscous liquid with weak compressibility. The boundary walls were simulated with a special set of fixed boundary particles, and no-slip boundary condition was considered. Computational results were compared to available analytical solutions for transient hydraulic processes. Good agreement is achieved for the whole transient stage of the considered problems until steady state is reached. The results of this study highlight the potential of SPH to tackle a broad range of problems in fluid mechanics.


2012 ◽  
Vol 09 (04) ◽  
pp. 1250057
Author(s):  
S. WANG

In this paper, we propose a Galerkin-based smoothed particle hydrodynamics (SPH) formulation with moving least-squares meshless approximation, applied to solid mechanics and large deformation. Our method is truly meshless and based on Lagrangian kernel formulation and stabilized nodal integration. The performance of the methodology proposed is tested through various simulations, demonstrating the attractive ability of particle methods to handle severe distortions and complex phenomena.


Sign in / Sign up

Export Citation Format

Share Document