Elastic Shrinkage-Swelling Modeling in Porous Microstructures: A Combined Finite Elements-Lattice Boltzmann-Numerical Approach

2017 ◽  
Author(s):  
Jean-Luc D. Adia ◽  
Julien Yvonnet ◽  
Qi-Chang He ◽  
Nhu-Cuong Tran ◽  
Julien Sanahuja
Keyword(s):  
Finite Elements ◽  
Lattice Boltzmann ◽  
Numerical Approach ◽  
Porous Microstructures

Thermal jet drilling of granite rock: a numerical 3D finite-element study

2021 ◽  
Vol 379 (2196) ◽  
pp. 20200128
Author(s):  
Timo Saksala ◽  
Reijo Kouhia ◽  
Ahmad Mardoukhi ◽  
Mikko Hokka
Keyword(s):  
Finite Elements ◽  
Numerical Study ◽  
Thermal Flux ◽  
Three Dimensional ◽  
Numerical Approach ◽  
Mass Scaling ◽  
Granite Rock ◽  
Fracture Dynamics ◽  
Rock Heterogeneity ◽  
Thermal Drilling

This paper presents a numerical study on thermal jet drilling of granite rock that is based on a thermal spallation phenomenon. For this end, a numerical method based on finite elements and a damage–viscoplasticity model are developed for solving the underlying coupled thermo-mechanical problem. An explicit time-stepping scheme is applied in solving the global problem, which in the present case is amenable to extreme mass scaling. Rock heterogeneity is accounted for as random clusters of finite elements representing rock constituent minerals. The numerical approach is validated based on experiments on thermal shock weakening effect of granite in a dynamic Brazilian disc test. The validated model is applied in three-dimensional simulations of thermal jet drilling with a short duration (0.2 s) and high intensity (approx. 3 MW m −2 ) thermal flux. The present numerical approach predicts the spalling as highly (tensile) damaged rock. Finally, it was shown that thermal drilling exploiting heating-forced cooling cycles is a viable method when drilling in hot rock mass. This article is part of the theme issue ‘Fracture dynamics of solid materials: from particles to the globe’.

Simulating blood rheology across scales: A hybrid LB-particle approach

2019 ◽  
Vol 30 (10) ◽  
pp. 1941003 ◽  
Author(s):  
Giacomo Falcucci ◽  
Marco Lauricella ◽  
Paolo Decuzzi ◽  
Simone Melchionna ◽  
Sauro Succi
Keyword(s):  
Lattice Boltzmann ◽  
Blood Cells ◽  
Hybrid Approach ◽  
Computational Cost ◽  
Blood Rheology ◽  
Numerical Approach ◽  
Particle Dynamics ◽  
Particle Methods ◽  
Blood Transport ◽  
Particle Approach

In this paper, we deploy the hybrid Lattice Boltzmann - Particle Dynamics (LBPD) method to investigate the transport properties of blood flow within arterioles and venules. The numerical approach is applied to study the transport of Red Blood Cells (RBC) through plasma, highlighting significant agreement with the experimental data in the seminal work by Fåhræus and Lindqvist. Moreover, the results provide evidence of an interesting hand-shaking between the range of validity of the proposed hybrid approach and the domain of viability of particle methods. A joint inspection of accuracy and computational cost, indicate that LBPD offers an appealing multiscale strategy for the study of blood transport across scales of motion, from macroscopic vessels, down to arterioles and venules, where particle methods can eventually take over.

Numerical investigation of nonlinear fluid–structure interaction dynamic behaviors under a general Immersed Boundary-Lattice Boltzmann-Finite Element method

2018 ◽  
Vol 29 (04) ◽  
pp. 1850038 ◽  
Author(s):  
Chun-Lin Gong ◽  
Zhe Fang ◽  
Gang Chen
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Lattice Boltzmann ◽  
Fluid Structure Interaction ◽  
Numerical Approach ◽  
Immersed Boundary ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Flexible Objects ◽  
Element Method

A numerical approach based on the immersed boundary (IB), lattice Boltzmann and nonlinear finite element method (FEM) is proposed to simulate hydrodynamic interactions of very flexible objects. In the present simulation framework, the motion of fluid is obtained by solving the discrete lattice Boltzmann equations on Eulerian grid, the behaviors of flexible objects are calculated through nonlinear dynamic finite element method, and the interactive forces between them are implicitly obtained using velocity correction IB method which satisfies the no-slip conditions well at the boundary points. The efficiency and accuracy of the proposed Immersed Boundary-Lattice Boltzmann-Finite Element method is first validated by a fluid–structure interaction (F-SI) benchmark case, in which a flexible filament flaps behind a cylinder in channel flow, then the nonlinear vibration mechanism of the cylinder-filament system is investigated by altering the Reynolds number of flow and the material properties of filament. The interactions between two tandem and side-by-side identical objects in a uniform flow are also investigated, and the in-phase and out-of-phase flapping behaviors are captured by the proposed method.

Comparison of three simulation methods for colloidal aggregates in Stokes flow: Finite elements, lattice Boltzmann and Stokesian dynamics

2013 ◽  
Vol 86 ◽  
pp. 199-209 ◽  
Author(s):  
Eva Schlauch ◽  
Martin Ernst ◽  
Ryohei Seto ◽  
Heiko Briesen ◽  
Martin Sommerfeld ◽  
...  
Keyword(s):  
Finite Elements ◽  
Stokes Flow ◽  
Lattice Boltzmann ◽  
Simulation Methods ◽  
Stokesian Dynamics ◽  
Colloidal Aggregates

scholarly journals Towards Infinite Tilings with Symmetric Boundaries

Symmetry ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 444
Author(s):  
Florian Stenger ◽  
Axel Voigt
Keyword(s):  
Finite Elements ◽  
Large Time ◽  
Time Discretization ◽  
Numerical Approach ◽  
Computational Effort ◽  
Special Boundaries ◽  
Hilliard Equation ◽  
Self Similar ◽  
Energy Stable ◽  
Cahn Hilliard Equation

Large-time coarsening and the associated scaling and statistically self-similar properties are used to construct infinite tilings. This is realized using a Cahn–Hilliard equation and special boundaries on each tile. Within a compromise between computational effort and the goal to reduce recurrences, an infinite tiling has been created and software which zooms in and out evolve forward and backward in time as well as traverse the infinite tiling horizontally and vertically. We also analyze the scaling behavior and the statistically self-similar properties and describe the numerical approach, which is based on finite elements and an energy-stable time discretization.

Two-dimensional decaying turbulence in confined geometries

2014 ◽  
Vol 05 (supp01) ◽  
pp. 1441008 ◽  
Author(s):  
Gabor Toth ◽  
Gabor Hazi
Keyword(s):  
Lattice Boltzmann ◽  
Regular Polygon ◽  
Numerical Approach ◽  
Initial Condition ◽  
Two Dimensional ◽  
Confined Geometries ◽  
Geometrical Constraints ◽  
Decaying Turbulence ◽  
Boltzmann Method ◽  
Physical Quantities

Several interesting phenomena have been observed simulating two-dimensional decaying turbulence in bounded domains. In this paper, an overview is given about our observations obtained by simulating freely decaying turbulence in different regular polygon shaped containers with no-slip walls. For these simulations the lattice Boltzmann method has been used as a numerical approach. The initial Reynolds number based on the container dimension was in the order of 10,000. The initial condition was the same in each simulation, therefore, we were able to compare the effect of geometrical constraints on the evolution of relevant physical quantities such as the kinetic energy and the enstrophy.

DIFFRACTION OF AN ACOUSTIC WAVE BY A PLATE IN A UNIFORM FLOW: A NUMERICAL APPROACH

2005 ◽  
Vol 13 (04) ◽  
pp. 689-709 ◽  
Author(s):  
S. JOB ◽  
E. LUNÉVILLE ◽  
J.-F. MERCIER
Keyword(s):  
Mach Number ◽  
Finite Elements ◽  
Acoustic Wave ◽  
Vortex Sheet ◽  
Acoustic Power ◽  
Numerical Approach ◽  
Uniform Flow ◽  
Finite Elements Method ◽  
Trailing Edge ◽  
Singular Coefficient

We study the diffraction in time harmonic regime of an acoustic wave by a rigid plate in the presence of a uniform flow in a duct. Contrary to prior analytical studies, using Wiener–Hopf techniques and thus restricted to semi-infinite plates, we use a finite elements method which allows us to deal with plates of finite length. To take into account irrotational perturbations induced by the trailing edge of the plate, a potential formulation requires the introduction of a vortex sheet behind the plate. The key point of the method is to get access at the singular coefficient of the velocity potential near the trailing edge, in order to cancel it using the so-called Kutta–Joukowski condition. This approach leads to an efficient finite elements method, and numerical computations are presented: we show the amplitude of the vortex sheet versus the Mach number and the plate length and the dissipated acoustic power versus the Mach number and the frequency. This method is extended to the case of two aligned plates to analyze the influence of the choice of the boundary condition on the downstream plate which interacts with a vortex sheet.

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