Evaluation of the Solid Boundary Treatment Methods in SPH

Abstract

The smoothed particle hydrodynamics (SPH) method has been proved as a powerful algorithm for fluid mechanics, especially in the simulation of free surface flows with high speeds or drastic impacts. The solid boundary treatment method is important for the accuracy and stability of the numerical results, as the support domain of fluid particles is truncated near the vicinity of the boundary. This paper presents two commonly used methods for simulating a solid boundary in SPH simulations. Emphasis is placed on the description of the methods, definition of the boundary particles’ parameters, and discussion of their advantages and shortcomings. The classical dam break simulation is conducted using self-developed code and open source models such as DualSPHysics and PySPH in order to investigate the effects of the boundary methods. The results show that methods based on dynamic boundary particles can simulate the free water surface well with a good agreement with experimental results. The conclusions can also be used in research for boundary implementation methods for practical ocean and coastal engineering problems with free surface flows.

Evaluation of particle‐based smoothed particle hydrodynamics boundary handling approaches in computer animation

“…For example, the dambreak experiment 17 is utilized by Crespo et al 26 using a global CFL-based time-stepping scheme proposed by Monaghan and Kos, 27 while Lee et al 28 use the method proposed by Morris et al 29 In the following, we briefly discuss the main purpose of some prominent, commonly used experiments. The widely used dambreak experiment 6,7,10,12,13,23,25,[30][31][32][33] involves an initial fluid volume flowing into a larger simulation domain and potentially interacting with obstacles placed within the simulation. It is used for both the evaluation of fluid simulation techniques 1,8 and boundary handling methods.…”

“…14 However, the setup of the experiment is altered in many ways. There are, for example, different sizes on the basin from 3 m long till tens of meters long 6,34 and of the initial fluid volume, for example, different shape and size of the fluid volume, 6,7,13 varying fluid parameters, for example, particle spacing and viscosity term, 23,31 and a varying number of obstacles, that is, no, 7,8,31 one, 12 or multiple/complex objects. 13 Another widely used experiment is the still water experiment 3,7,12,[35][36][37] used to investigate the fluid behavior in a steady state.…”

“…In the following, we briefly discuss the main purpose of some prominent, commonly used experiments. The widely used dambreak experiment 6,7,10,12,13,23,25,30‐33 involves an initial fluid volume flowing into a larger simulation domain and potentially interacting with obstacles placed within the simulation. It is used for both the evaluation of fluid simulation techniques 1,8 and boundary handling methods 13,25 .…”

SPH Simulation for Short Fibre Recycling Using Water Jet Alignment

“…Repulsive particles, introduced initially by Monaghan [29], are fixed along the boundary and exert a repulsive force on the fluid particles in a form given by the Lennard-Jones potential. However, with this method the motion of the fluid near the boundary cannot be simulated accurately resulting in poor conservation properties [22].…”

Semi‐analytical treatment of spherical solids in smoothed‐particle hydrodynamics fluid simulations

“…This thus allows the extension of fluid–boundary interactions to fluid–solid interactions, where solid objects within the flow are effectively seen as a boundary to the SPH fluid, and can therefore be modeled in the same way. For example, by placing fixed ghost fluid particles within a mobile solid, as is often done for boundaries and described as the dynamic boundary method, 8 it is possible to calculate the SPH forcings on these particles, then aggregate and apply them to the solid equations of motion in order to handle the fluid–solid coupling. Any solid–solid coupling within the system is usually handled by means of another method such as the Discrete Element Method (DEM), which, with an appropriate implementation is able to model the interaction of both planar and curved solid surfaces.…”