A lattice Boltzmann model for heat transfer in heterogeneous media

In this paper, the Lattice Boltzmann method is used to simulate heat and mass diffusion in bio-based building materials. The numerical method is presented and the methodology developed to reduce the calculation time is described. The 3-D morphologies of spruce and wood fibers are obtained using synchrotron X-ray micro-tomography. Equivalent macroscopic properties (heat conductivity and mass diffusivity) are therefore determined from the real micro-structure of the materials. The results reveal the anisotropy of the studied materials. The computed equivalent heat conductivity varies from 0.036 W m −1 K −1 to 0.52 W m −1 K −1 and the computed dimensionless mass diffusivity varies from 0.0088 to 0.78 depending on the materials and on the diffusion directions. Using these results, morphology families are identified and simple expressions are proposed to predict the equivalent properties as a function of phase properties and solid fraction.

International Journal of Thermal Sciences

Section: Introductionmentioning

confidence: 99%

Heat and moisture diffusion in spruce and wood panels computed from 3-D morphologies using the Lattice Boltzmann method

Louërat

Ayouz

Perré

2018

“…[9], a D2Q5 lattice for two-dimensional problems is used for numerical validation. For three-dimensional investigated domains, one can invoke a D3Q7 lattice [21]. Such choice can save computational cost efficiently, which is crucial for industrial-level simulation, as explained in our previous work [20].…”

Section: Evolving Equationmentioning

confidence: 99%

A lattice Boltzmann model for heat transfer in porous media

Yang

International Journal of Heat and Mass Transfer

2017

Self Cite

Porous media are commonly found not only in the nature but also in industries. Furthermore, porous media is an important research prototype for a diversity of disciplines. So far a REV (representative elementary volume) scale lattice Boltzmann (LB) model has been proposed and popularly used for investigation on heat transfer in porous media. Unfortunately, such model suffers from a serious drawback that it can not address an investigated domain where the heat capacitance (the product of density and specific heat capacity) of porous media varies spatially obviously. Such deficit restricts dramatically its applicable range. The purpose of the present work is to remedy such serious shortcoming in a simple way. Numerical validation demonstrates the capability and reliability of the present model. In order to clearly show the advantage of the present model, here a single-relaxation-time LB model is taken as an example to illustrate how to remedy the shortcoming of previous models. Its multiple-relaxation-time counterpart can be established straightforwardly in the same way.

“…[19], a D2Q5 lattice for two-dimensional problems is used for modelling concentration field. For three-dimensional investigated domains, one can invoke a D3Q7 lattice [42]. Such choice can save computational cost efficiently, which is crucial for industrial-level simulation, as explained in our previous work [41].…”

Section: Evolving Equationmentioning

confidence: 99%

Simulation of double diffusive convection in fluid-saturated porous media by lattice Boltzmann method

Yang

International Journal of Heat and Mass Transfer

2017

Self Cite

The research on double diffusive convection in porous media is important to deepen our insights into sustainable development and environment protection. A lattice Boltzmann (LB) model for REV (representative elementary volume) scale simulation of double diffusive convection in fluid-saturated porous media is proposed in the present work. It can work well not only for porous media with uniform porosity but also for non-uniform porous media. Several benchmark tests are adopted to validate its capability. The good agreement with previous publications demonstrates its applicability. It can provide an alternative numerical tool for modelling complex heat and mass transfer in fluid-saturated porous media beyond double diffusive convection, such as heat and moisture transfer in multi-layer building materials.