Validation Study of Smoothed Particle Hydrodynamics in Fluid and Structure Interaction and the Comparison to Boundary Element Method

2017 ◽  
Author(s):  
Nhu Nguyen ◽  
Krish P. Thiagarajan ◽  
Matthew Cameron
Keyword(s):  
Boundary Element Method ◽  
Boundary Element ◽  
Smoothed Particle Hydrodynamics ◽  
Computational Time ◽  
Floating Structure ◽  
Structure Interaction ◽  
Advantages And Disadvantages ◽  
Particle Hydrodynamics ◽  
Smoothed Particle ◽  
Element Method

The purpose of this research is to validate the usage of Smoothed Particle Hydrodynamics (SPH) method in solving fluid-structure interaction problems as well as study its advantages and disadvantages compared to another well-known technique Boundary Element Method (BEM). The goal is achieved by 1) evaluating the Response Amplitude Operator (RAO) and 2) analyzing the drifting motion of a 1:10 scaled 3m-discus oceanographic buoy developed by the National Oceanographic and Atmospheric Administration (NOAA), using both experimental and numerical approaches. For the experimental study, the testing was carried out in an 8-m long wave tank and the buoy motions were measured using non-intrusive techniques. For numerical analysis, the project used DualSPHysics — open source code — and ANSYS AQWA — one of the leading software widely used in the marine applications — to simulate all the experimental scenarios via SPH and BEM techniques respectively. It is observed that while BEM has clear advantages in computational time and the ability to study applicable range of frequencies, SPH, in addition to its capability to simulate drifting motion of the floating structure, has shown to outperform the RAO predictions from BEM (especially in low frequency region). In higher frequency regions, the lack of experimental data hinders the conclusion on which method might be more suitable, as both have their own limitations.

Weighted Finite Difference and Boundary Element Methods Applied to Groundwater Pollution Problems

1991 ◽  
Vol 23 (1-3) ◽  
pp. 517-524
Author(s):  
M. Kanoh ◽  
T. Kuroki ◽  
K. Fujino ◽  
T. Ueda
Keyword(s):  
Boundary Element Method ◽  
Finite Difference ◽  
Finite Difference Method ◽  
Boundary Element ◽  
Difference Method ◽  
Groundwater Pollution ◽  
Small Region ◽  
Boundary Element Methods ◽  
Computational Time ◽  
Element Method

The purpose of the paper is to apply two methods to groundwater pollution in porous media. The methods are the weighted finite difference method and the boundary element method, which were proposed or developed by Kanoh et al. (1986,1988) for advective diffusion problems. Numerical modeling of groundwater pollution is also investigated in this paper. By subdividing the domain into subdomains, the nonlinearity is localized to a small region. Computational time for groundwater pollution problems can be saved by the boundary element method; accurate numerical results can be obtained by the weighted finite difference method. The computational solutions to the problem of seawater intrusion into coastal aquifers are compared with experimental results.

Smoothed particle hydrodynamics versus finite element method for blast impact

2013 ◽  
Vol 61 (1) ◽  
pp. 111-121 ◽  
Author(s):  
T. Jankowiak ◽  
T. Łodygowski
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Smoothed Particle Hydrodynamics ◽  
Concrete Slab ◽  
The Finite Element Method ◽  
Particle Hydrodynamics ◽  
Mesh Density ◽  
Smoothed Particle ◽  
Element Method

Abstract The paper considers the failure study of concrete structures loaded by the pressure wave due to detonation of an explosive material. In the paper two numerical methods are used and their efficiency and accuracy are compared. There are the Smoothed Particle Hydrodynamics (SPH) and the Finite Element Method (FEM). The numerical examples take into account the dynamic behaviour of concrete slab or a structure composed of two concrete slabs subjected to the blast impact coming from one side. The influence of reinforcement in the slab (1, 2 or 3 layers) is also presented and compared with a pure concrete one. The influence of mesh density for FEM and the influence of important parameters in SPH like a smoothing length or a particle distance on the quality of the results are discussed in the paper

scholarly journals Hydrodynamic Interactions in Multiple Body Array: A Simple and Fast Approach Coupling Boundary Element Method and Plane Wave Approximation

2013 ◽  
Author(s):  
Jitendra Singh ◽  
Aurélien Babarit
Keyword(s):  
Boundary Element Method ◽  
Plane Wave ◽  
Boundary Element ◽  
Hydrodynamic Interaction ◽  
Computational Time ◽  
Linear Potential ◽  
Wave Approximation ◽  
Interaction Problem ◽  
Plane Wave Approximation ◽  
Element Method

The hydrodynamic forces acting on an isolated body could be considerably different than those when it is considered in an array of multiple bodies, due to wave interactions among them. In this context, we present in this paper a numerical approach based on the linear potential flow theory to solve full hydrodynamic interaction problem in a multiple body array. In contrast to the previous approaches that considered all bodies in an array as a single unit, the present approach relies on solving for an isolated body. The interactions among the bodies are then taken into account via plane wave approximation in an iterative manner. The boundary value problem corresponding to a isolated body is solved by the Boundary Element Method (BEM). The approach is useful when the bodies are sufficiently distant from each other, at-least greater than five times the characteristic dimensions of the body. This is a valid assumption for wave energy converter devices array of point absorber type, which is our target application at a later stage. The main advantage of the proposed approach is that the computational time requirement is significantly less than the commonly used direct BEM. The time savings can be realized for even small arrays consisting of four bodies. Another advantage is that the computer memory requirements are also significantly smaller compared to the direct BEM, allowing us to consider large arrays. The numerical results for hydrodynamic interaction problem in two arrays consisting of 25 cylinders and same number of rectangular flaps are presented to validate the proposed approach.

An Improved Assembling Algorithm in Boundary Elements With Galerkin Weighting Applied to Three-Dimensional Stokes Flows

2017 ◽  
Vol 140 (1) ◽  
Author(s):  
Sofia Sarraf ◽  
Ezequiel López ◽  
Laura Battaglia ◽  
Gustavo Ríos Rodríguez ◽  
Jorge D'Elía
Keyword(s):  
Boundary Element Method ◽  
Linear System ◽  
Boundary Element ◽  
Numerical Solutions ◽  
Three Dimensional ◽  
Boundary Integral ◽  
Computational Time ◽  
Creeping Flows ◽  
Order Of Magnitude ◽  
Element Method

In the boundary element method (BEM), the Galerkin weighting technique allows to obtain numerical solutions of a boundary integral equation (BIE), giving the Galerkin boundary element method (GBEM). In three-dimensional (3D) spatial domains, the nested double surface integration of GBEM leads to a significantly larger computational time for assembling the linear system than with the standard collocation method. In practice, the computational time is roughly an order of magnitude larger, thus limiting the use of GBEM in 3D engineering problems. The standard approach for reducing the computational time of the linear system assembling is to skip integrations whenever possible. In this work, a modified assembling algorithm for the element matrices in GBEM is proposed for solving integral kernels that depend on the exterior unit normal. This algorithm is based on kernels symmetries at the element level and not on the flow nor in the mesh. It is applied to a BIE that models external creeping flows around 3D closed bodies using second-order kernels, and it is implemented using OpenMP. For these BIEs, the modified algorithm is on average 32% faster than the original one.

scholarly journals Smoothed Particle Hydrodynamics Simulation of a Mariculture Platform under Waves

Water ◽  
2021 ◽  
Vol 13 (20) ◽  
pp. 2847
Author(s):  
Feng Zhang ◽  
Li Zhang ◽  
Yanshuang Xie ◽  
Zhiyuan Wang ◽  
Shaoping Shang
Keyword(s):  
Smoothed Particle Hydrodynamics ◽  
Graphics Processing Units ◽  
Degrees Of Freedom ◽  
High Tide ◽  
Theoretical Data ◽  
Emergency Evacuation ◽  
Water Levels ◽  
Computational Time ◽  
Particle Hydrodynamics ◽  
Smoothed Particle

This work investigates the dynamic behaviors of floating structures with moorings using open−source software for smoothed particle hydrodynamics. DualSPHysics permits us to use graphics processing units to recreate designs that include complex calculations at high resolution with reasonable computational time. A free damped oscillation was simulated, and its results were compared with theoretical data to validate the numerical model developed. The simulated three degrees of freedom (3−DoF) (surge, heave, and pitch) of a rectangular floating box have excellent consistency with experimental data. MoorDyn was coupled with DualSPHysics to include a mooring simulation. Finally, we modelled and simulated a real mariculture platform on the coast of China. We simulated the 3−DoF of this mariculture platform under a typical annual wave and a Typhoon Dujuan wave. The motion was light and gentle under the typical annual wave but vigorous under the Typhoon Dujuan wave. Experiments at different tidal water levels revealed an earlier motion response and smaller motion range during the high tide. The results reveal that DualSPHysics combined with MoorDyn is an adaptive scheme to simulate a coupled fluid–solid–mooring system. This work provides support to disaster warning, emergency evacuation, and proper engineering design.

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