Asymmetric Adaptive Particle Refinement in SPH and Its Application in Soil Cutting Problems

2018 ◽  
Vol 15 (06) ◽  
pp. 1850052 ◽  
Author(s):  
Hao Wu ◽  
Jian Wang ◽  
Jianhua Wang ◽  
Chencong Liao
Keyword(s):  
Contact Forces ◽  
Adaptive Refinement ◽  
Local Instability ◽  
Cutting Test ◽  
Particle Hydrodynamics ◽  
Smoothed Particle ◽  
Soil Cutting ◽  
Particle Refinement ◽  
Cutting Problems ◽  
Refinement Algorithm

In this study, a novel asymmetric adaptive particle refinement algorithm in smoothed particle hydrodynamics (SPH) is developed for soil cutting problems. Each candidate particle that located at the cutting blade of the structure is split into two “children” particles to minimize the oscillation of the contact force. And thus reduce the local instability. To minimize the density refinement error, a numerical method to determine the optimal smoothing lengths for “children” particles is given. To verify the accuracy of proposed algorithm, the adaptive refinement procedure are implemented into two models: one for soil cutting test on plane strain condition and the other for sample drilling test on axisymmetric condition. The observed flow pattern of the soil and contact forces are compared with laboratory experimental data available in the literature. Results indicate that the proposed asymmetric adaptive refinement algorithm could significantly avoid severe local instability and contributes to high-accuracy simulation.

scholarly journals Smoothed Particle Hydrodynamics Simulation of Orthogonal Cutting with Enhanced Thermal Modeling

2021 ◽  
Vol 11 (3) ◽  
pp. 1020
Author(s):  
Mohamadreza Afrasiabi ◽  
Hagen Klippel ◽  
Matthias Roethlin ◽  
Konrad Wegener
Keyword(s):  
Smoothed Particle Hydrodynamics ◽  
Metal Cutting ◽  
Thermal Modeling ◽  
Orthogonal Cutting ◽  
Detection Algorithm ◽  
Mesh Free ◽  
Particle Hydrodynamics ◽  
Smoothed Particle ◽  
Boundary Treatments ◽  
Cutting Problems

Smoothed Particle Hydrodynamics (SPH) is a mesh-free numerical method that can simulate metal cutting problems efficiently. The thermal modeling of such processes with SPH, nevertheless, is not straightforward. The difficulty is rooted in the computationally demanding procedures regarding convergence properties and boundary treatments, both known as SPH Grand Challenges. This paper, therefore, intends to rectify these issues in SPH cutting models by proposing two improvements: (1) Implementing a higher-order Laplacian formulation to solve the heat equation more accurately. (2) Introducing a more realistic thermal boundary condition using a robust surface detection algorithm. We employ the proposed framework to simulate an orthogonal cutting process and validate the numerical results against the available experimental measurements.

scholarly journals An SPH Approach for Non-Spherical Particles Immersed in Newtonian Fluids

2020 ◽  
Author(s):  
Nadine Kijanski ◽  
David Krach ◽  
Holger Steeb
Keyword(s):  
Numerical Simulations ◽  
Construction Materials ◽  
Contact Forces ◽  
Solid Particles ◽  
Spherical Particles ◽  
Particle Hydrodynamics ◽  
Smoothed Particle ◽  
Solid Bodies ◽  
Fluid Solid Interaction ◽  
Modelling Approach

Solid particles immersed in a fluid can be found in many engineering, environmental or medical fields. Applications are suspensions, sedimentation processes or procedural processes in the production of medication, food or construction materials. While homogenized behavior of these applications is well understood, contributions in the field of pore-scale fully resolved numerical simulations with non-spherical particles are rare. Using Smoothed Particle Hydrodynamics (SPH) as a simulation framework, we therefore present a modelling approach for Direct Numerical Simulations (DNS) of single-phase fluid containing non-spherically formed solid aggregates. Notable and discussed model specifications are the surface-coupled fluid-solid interaction forces as well as the contact forces between solid aggregates. The focus of this contribution is the numerical modelling approach and its implementation in SPH. Since SPH presents a fully resolved approach, the construction of arbitrary shaped particles is conveniently realizable. After validating our model for single non-spherical particles, we therefore investigate the motion of solid bodies in a Newtonian fluid and their interaction with the surrounding fluid by analyzing velocity fields of shear flow with respect to hydromechanical and contact forces. Results show a dependency of the motion and interaction of solid particles on their form and orientation. While spherical particles move to the centerline region, ellipsoidal particles move and rotate due to vortexes formation in the fluid flow in between.

scholarly journals An SPH Approach for Non-Spherical Particles Immersed in Newtonian Fluids

Materials ◽  
2020 ◽  
Vol 13 (10) ◽  
pp. 2324
Author(s):  
Nadine Kijanski ◽  
David Krach ◽  
Holger Steeb
Keyword(s):  
Numerical Simulations ◽  
Vortex Formation ◽  
Construction Materials ◽  
Contact Forces ◽  
Solid Particles ◽  
Spherical Particles ◽  
Modeling Approach ◽  
Particle Hydrodynamics ◽  
Smoothed Particle ◽  
Solid Bodies

Solid particles immersed in a fluid can be found in many engineering, environmental or medical fields. Applications are suspensions, sedimentation processes or procedural processes in the production of medication, food or construction materials. While homogenized behavior of these applications is well understood, contributions in the field of pore-scale fully resolved numerical simulations with non-spherical particles are rare. Using Smoothed Particle Hydrodynamics (SPH) as a simulation framework, we therefore present a modeling approach for Direct Numerical Simulations (DNS) of single-phase fluid containing non-spherically formed solid aggregates. Notable and discussed model specifications are the surface-coupled fluid–solid interaction forces as well as the contact forces between solid aggregates. The focus of this contribution is the numerical modeling approach and its implementation in SPH. Since SPH presents a fully resolved approach, the construction of arbitrary shaped particles is conveniently realizable. After validating our model for single non-spherical particles, we therefore investigate the motion of solid bodies in a Newtonian fluid and their interaction with the surrounding fluid and with other solid bodies by analyzing velocity fields of shear flow with respect to hydromechanical and contact forces. Results show a dependency of the motion and interaction of solid particles on their form and orientation. While spherical particles move to the centerline region, ellipsoidal particles move and rotate due to vortex formation in the fluid flow in between.

Multiphysics SPH Simulations With Local Particle Coarsening

2011 ◽  
Author(s):  
Christian Ulrich ◽  
Sven Bednarek ◽  
Thomas Rung
Keyword(s):  
Ocean Engineering ◽  
Particle Coarsening ◽  
Particle Properties ◽  
Effective Strategies ◽  
Computational Performance ◽  
Large Numbers ◽  
Current Location ◽  
Particle Hydrodynamics ◽  
Smoothed Particle ◽  
Particle Refinement

The paper reports on Smoothed-Particle-Hydrodynamics (SPH) for multi-physics water/soil interaction computations with dynamic particle coarsening. The procedure is supposed to be applied to harbour and ocean engineering hydrodynamic problems focussing on sediment scouring. This type of simulation usually implies large computational domains, fluid-soil interaction and complex geometries leading to large numbers of particles. To achieve a reasonable time-to-solution even for full-scale simulations, effective strategies to increase the computational performance are needed. We present a dynamic particle refinement/coarsening strategy based on variable particle masses and spacings. The particle properties are updated in accordance to their current location. Validation studies refer to different water/soil interaction test cases. Results obtained from the present refinement/coarsening approach show an encouraging predictive and computational performance.

Sign in / Sign up

Export Citation Format

Share Document