Lattice Boltzmann Simulations for Thermal Conductivity Estimation in Heterogeneous Materials

2009 ◽  
Vol 283-286 ◽  
pp. 364-369 ◽  
Author(s):  
M.R. Arab ◽  
Bernard Pateyron ◽  
Mohammed El Ganaoui ◽  
Nicolas Calvé
Keyword(s):  
Thermal Conductivity ◽  
Porous Medium ◽  
Lattice Boltzmann ◽  
Numerical Study ◽  
Theoretical Models ◽  
Short Description ◽  
Physical Parameters ◽  
Two Dimensional ◽  
Lattice Boltzmann Simulations ◽  
Boltzmann Method

For simulating flows in a porous medium, a numerical tool based on the Lattice Boltzmann Method (LBM) is developed with regards to the classical D2Q9 model. A short description of this model is presented. This technique, applied to two-dimensional configurations, indicates its ability to simulate phenomena of heat and mass transfer. The numerical study is extended to estimate physical parameters that characterize porous materials, like the so-called Effective Thermal Conductivity (ETC) which is of our interest in this paper. Obtained results are compared with those which could be found analytically and by theoretical models. Finally, a porous medium is considered to find its ETC.

scholarly journals Predicting porosity, permeability, and tortuosity of porous media from images by deep learning

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Krzysztof M. Graczyk ◽  
Maciej Matyka
Keyword(s):  
Neural Networks ◽  
Porous Medium ◽  
Porous Media ◽  
Deep Learning ◽  
Lattice Boltzmann ◽  
Good Accuracy ◽  
Two Dimensional ◽  
Empirical Estimate ◽  
Flow Through ◽  
Boltzmann Method

AbstractConvolutional neural networks (CNN) are utilized to encode the relation between initial configurations of obstacles and three fundamental quantities in porous media: porosity ($$\varphi$$ φ ), permeability (k), and tortuosity (T). The two-dimensional systems with obstacles are considered. The fluid flow through a porous medium is simulated with the lattice Boltzmann method. The analysis has been performed for the systems with $$\varphi \in (0.37,0.99)$$ φ ∈ ( 0.37 , 0.99 ) which covers five orders of magnitude a span for permeability $$k \in (0.78, 2.1\times 10^5)$$ k ∈ ( 0.78 , 2.1 × 10 5 ) and tortuosity $$T \in (1.03,2.74)$$ T ∈ ( 1.03 , 2.74 ) . It is shown that the CNNs can be used to predict the porosity, permeability, and tortuosity with good accuracy. With the usage of the CNN models, the relation between T and $$\varphi$$ φ has been obtained and compared with the empirical estimate.

Lattice-Boltzmann simulations of particles in non-zero-Reynolds-number flows

1999 ◽  
Vol 385 ◽  
pp. 41-62 ◽  
Author(s):  
DEWEI QI
Keyword(s):  
Reynolds Number ◽  
Cross Section ◽  
Lattice Boltzmann ◽  
Three Dimensional ◽  
Spherical Particles ◽  
Computational Results ◽  
Two Dimensional ◽  
Lattice Boltzmann Simulations ◽  
Boltzmann Method ◽  
Reynolds Number Flows

A lattice-Boltzmann method has been developed to simulate suspensions of both spherical and non-spherical particles in finite-Reynolds-number flows. The results for sedimentation of a single elliptical particle are shown to be in excellent agreement with the results of Huang, Hu & Joseph (1998) who used a finite-element method. Sedimentation of two-dimensional circular and rectangular particles in a two-dimensional channel and three-dimensional spherical particles in a tube with square cross-section is simulated. Computational results are consistent with experimentally observed phenomena, such as drafting, kissing and tumbling.

Two-Dimensional Simulation of Magnetohydrodynamic Two-Phase Flow in Random Porous Media Using the Lattice Boltzmann Method

2010 ◽  
Author(s):  
Mahshid Hadavand ◽  
Aydin Nabovati ◽  
Antonio C. M. Sousa
Keyword(s):  
Magnetic Field ◽  
Porous Medium ◽  
Lattice Boltzmann Method ◽  
Lattice Boltzmann ◽  
Phase Flow ◽  
Two Dimensional ◽  
Two Phase ◽  
Single Relaxation Time ◽  
Boltzmann Method ◽  
The Magnetic Field

The present work employs the single relaxation time lattice Boltzmann method along with the pseudo potential model for the two-phase flow simulation of a ferrofluid in a random two-dimensional medium under the influence of a spatially variable external magnetic field. The magnetic field is created and controlled by placing a permanent magnet at the outlet end of the channel filled with a porous medium. The magnitude of the magnetic force acting on the ferrofluid is controlled by changing the distance of the magnet from the channel outlet. The spatially variable magnetic field strength was analytically calculated inside the channel using the available relations in the literature. The main goal of the present work is to qualitatively study the applicability of the single relaxation time (SRT) lattice Boltzmann method (LBM) to modelling flow of a ferrofluid and its steering into porous media. Penetration of the ferrofluid into the porous medium, which is initially filled with a fluid with no magnetic properties, was simulated in time. The simulation results for the flow front are presented and the effect of the magnetic field strength on the rate of flow penetration and front advancement was studied qualitatively. The LBM has proved to be a powerful tool for modelling flows, which involve multi-physics in complex geometries, when mesoscopic inter-particle forces and interaction with external complex forces have to be determined.

SIMULATION OF TWO-DIMENSIONAL OSCILLATING FLOW USING THE LATTICE BOLTZMANN METHOD

2006 ◽  
Vol 17 (05) ◽  
pp. 615-630 ◽  
Author(s):  
Y. WANG ◽  
Y. L. HE ◽  
G. H. TANG ◽  
W. Q. TAO
Keyword(s):  
Pressure Gradient ◽  
Lattice Boltzmann Method ◽  
Lattice Boltzmann ◽  
Numerical Study ◽  
Oscillating Flow ◽  
Two Dimensional ◽  
Constant Wall Temperature ◽  
Flow And Heat Transfer ◽  
Extrapolation Scheme ◽  
Boltzmann Method

A numerical study is presented for forced convection of an incompressible oscillating flow in a two-dimensional channel at constant wall temperature using the lattice Boltzmann method. The oscillatory motion of the fluid in the channel is driven by a periodic pressure gradient. The model adopted in this study is the coupled lattice Bhatnagar-Gross-Krook model. Pressure boundary condition is used in the inlet and outlet boundaries, and extrapolation scheme is used in the solid boundaries. The dependence of the flow and heat transfer characteristics on different Womersley numbers and the amplitudes of the pressure gradient are presented. Results are consistent with those from previous numerical simulations and theoretical analyses.

Symmetry Breaking of Flow in 2D Symmetric Channels: Simulations by Lattice-Boltzmann Method

1997 ◽  
Vol 08 (04) ◽  
pp. 859-867 ◽  
Author(s):  
Li-Shi Luo
Keyword(s):  
Boltzmann Equation ◽  
Symmetry Breaking ◽  
Lattice Boltzmann Method ◽  
Lattice Boltzmann ◽  
Numerical Study ◽  
Nonlinear Flow ◽  
Lattice Boltzmann Equation ◽  
Two Dimensional ◽  
Flow Phenomena ◽  
Boltzmann Method

In this paper, a numerical study of nonlinear flow phenomena in two-dimensional symmetric channels using the lattice-Boltzmann equation method is presented. The results are compared with both experimental results and other numerical results using some traditional methods. Comparisons are found to be quantitatively accurate.

Nozzle Flow of a Ship Propulsion Equipment Driven by High-Pressure Gas

2003 ◽  
Author(s):  
Michihisa Tsutahara ◽  
Kazuhiko Ogawa ◽  
Masahiko Sakamoto ◽  
Takahiro Matsui
Keyword(s):  
High Pressure ◽  
Gas Phase ◽  
Lattice Boltzmann ◽  
Water Waves ◽  
Numerical Study ◽  
Nozzle Flow ◽  
Two Dimensional ◽  
Open Type ◽  
Ship Propulsion ◽  
Boltzmann Method

A two-dimensional open type nozzle has been investigated for ship propulsion equipment. In this nozzle, a high-pressure gas (air) is ejected from below into water flow and accelerates the water towards downstream. Two cases, continuously and intermittently ejection of gas, are studied. In the latter case, the thrust itself is smaller than that in the former case, but thrust based on the ejection duration is larger. Even in the continuously ejected case, it was found that the gas phase and the water phase are separated. The water waves of large amplitude appear on the interface inside the nozzle and these waves propagate towards downstream. A numerical study by the lattice Boltzmann method was also performed to clarify the flow inside the nozzle.

Natural Convection in a Porous Medium Rectangular Cavity with an Applied Vertical Magnetic Field Using Lattice Boltzmann Method

2011 ◽  
Vol 110-116 ◽  
pp. 839-846 ◽  
Author(s):  
Hamid Reza Ashorynejad ◽  
Mousa Farhadi ◽  
Kurosh Sedighi ◽  
Arman Hasanpour
Keyword(s):  
Magnetic Field ◽  
Porous Medium ◽  
Lattice Boltzmann Method ◽  
Lattice Boltzmann ◽  
Numerical Study ◽  
Flow Characteristics ◽  
Mhd Flow ◽  
Darcy Number ◽  
Hydrodynamic Characteristics ◽  
Boltzmann Method

A numerical study of the magnetohydrodynamic (MHD) flow in a square cavity filled with porous medium is presented by Lattice Boltzmann Method (LBM). The left and right vertical walls of the cavity are kept at constant but different temperatures while both the top and bottom horizontal walls are insulated. The effects of the controlling parameters involved in the heat transfer and hydrodynamic characteristics are studied in detail. The results show that heat and mass transfer mechanisms and the flow characteristics inside the enclosure depend strongly on the strength of the magnetic field and Darcy number. The average Nusselt number decreases with rising values of the Hartmann number while this increases with increasing values of the Darcy number.

Lattice Boltzmann Simulations of Flow in Two-Dimensional Lid-Driven Semi-Circular Cavity

2011 ◽  
Author(s):  
Fan Yang ◽  
Lianguo Liu ◽  
Xuming Shi ◽  
Xueyan Guo
Keyword(s):  
Lattice Boltzmann ◽  
Reynolds Numbers ◽  
Central Line ◽  
Circular Cavity ◽  
Two Dimensional ◽  
Order Accuracy ◽  
Curved Boundary ◽  
Dimensionless Velocity ◽  
Lattice Boltzmann Simulations ◽  
Boltzmann Method

The flow pattern in a two-dimensional lid-driven semi-circular cavity is analyzed using the lattice Boltzmann method (LBM). The treatment of curved boundary with second-order accuracy is used. The streamline contours as well as dimensionless velocity component along the central line of a semi-circular cavity are obtained for different Reynolds numbers. The numerical results show that the LBM can capture the formation of primary, secondary and tertiary vortices exactly as the Reynolds number increases and has a great agreement with those of current literatures.

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