THREE-DIMENSIONAL THERMAL LATTICE BOLTZMANN SIMULATION OF NATURAL CONVECTION IN A CUBIC CAVITY

2007 ◽  
Vol 21 (01) ◽  
pp. 87-96 ◽  
Author(s):  
C. S. NOR AZWADI ◽  
T. TANAHASHI
Keyword(s):  
Distribution Function ◽  
Natural Convection ◽  
Lattice Boltzmann ◽  
Three Dimensional ◽  
Velocity Model ◽  
Lattice Boltzmann Model ◽  
Convection Flow ◽  
Energy Density Distribution ◽  
Lattice Boltzmann Simulation ◽  
Thermal Lattice Boltzmann

In this paper, a three-dimensional (3D) thermal lattice Boltzmann model is proposed to simulate 3D incompressible thermal flow problem. Our model is based on the double-distribution function approach. We found that a new and simple lattice type of eight-velocity model for the internal energy density distribution function can be developed, where the viscous and compressive heating effects are negligible. Numerical results of 3D natural convection flow in a cubic cavity are presented.

SIMPLIFIED THERMAL LATTICE BOLTZMANN IN INCOMPRESSIBLE LIMIT

2006 ◽  
Vol 20 (17) ◽  
pp. 2437-2449 ◽  
Author(s):  
C. S. NOR AZWADI ◽  
T. TANAHASHI
Keyword(s):  
Distribution Function ◽  
Density Distribution ◽  
Lattice Boltzmann ◽  
Porous Plate ◽  
Velocity Model ◽  
Distribution Functions ◽  
Density Distribution Function ◽  
Energy Density Distribution ◽  
Thermal Lattice Boltzmann ◽  
Lattice Boltzmann Scheme

In this paper, an incompressible thermohydrodynamics for the lattice Boltzmann scheme is developed. The basic idea is to solve the velocity field and the temperature field using two different distribution functions. A derivation of the lattice Boltzmann scheme from the continuous Boltzmann equation is discussed in detail. By using the same procedure as in the derivation of the discretised density distribution function, we found that a new lattice of four-velocity model for internal energy density distribution function can be developed where the viscous and compressive heating effects are negligible. This model is validated by the numerical simulation of the porous plate couette flow problem where the analytical solution exists and the natural convection flows in a square cavity.

Modeling of collapsing cavitation bubble near solid wall by 3D pseudopotential multi-relaxation-time lattice Boltzmann method

2017 ◽  
Vol 232 (3) ◽  
pp. 445-456 ◽  
Author(s):  
Minglei Shan ◽  
Yu Yang ◽  
Hao Peng ◽  
Qingbang Han ◽  
Changping Zhu
Keyword(s):  
Relaxation Time ◽  
Lattice Boltzmann ◽  
Cavitation Bubble ◽  
Solid Wall ◽  
Three Dimensional ◽  
Lattice Boltzmann Model ◽  
Bubble Collapse ◽  
Lattice Boltzmann Simulation ◽  
Boltzmann Method ◽  
Boltzmann Model

Understanding the dynamic characteristic of the cavitation bubble near a solid wall is a fundamental issue for the bubble collapse application and prevention. In the present work, an improved three-dimensional multi-relaxation-time pseudopotential lattice Boltzmann model is adopted to investigate the cavitation bubble collapse near the solid wall. With respect to thermodynamic consistency, Laplace law verification, the three-dimensional pseudopotential multi-relaxation-time lattice Boltzmann model is investigated. By the theoretical analysis, it is proved that the model can be regarded as a solver of the Rayleigh–Plesset equation, and confirmed by comparing the results of the lattice Boltzmann simulation and the Rayleigh–Plesset equation calculation for the case of cavitation bubble collapse in the infinite medium field. The bubble collapse near the solid wall is modeled using the improved pseudopotential multi-relaxation-time lattice Boltzmann model. We find the lattice Boltzmann simulation and the experimental results have the same dynamic process by comparing the bubble profiles evolution. Form the pressure field and the velocity field evolution it is found that the tapered higher pressure region formed near the top of the bubble is a crucial driving force inducing the bubble collapse. This exploratory research demonstrates that the lattice Boltzmann method is an alternative tool for the study of the interaction between collapsing cavitation bubble and matter.

Lattice Boltzmann Simulation of Flow and Heat Transfer Characteristics in a Symmetrically Bifurcated Microchannel

2004 ◽  
Author(s):  
Keqiang Xing ◽  
Yong Tao
Keyword(s):  
Heat Transfer ◽  
Lattice Boltzmann ◽  
Constant Heat Flux ◽  
Lattice Boltzmann Model ◽  
Straight Tube ◽  
Lattice Boltzmann Simulation ◽  
Flux Boundary Conditions ◽  
Boltzmann Method ◽  
Thermal Lattice Boltzmann ◽  
Transfer Problems

The lattice Boltzmann method (LBM) as a relatively new numerical scheme has recently achieved considerable success in simulating fluid flows and associated transport phenomena. However, application of this method to heat transfer problems has been at a stage of infancy. In this work, a thermal lattice Boltzmann model is employed to simulate a two-dimensional, steady flow in a symmetric bifurcation under constant temperature and constant heat flux boundary conditions. The bifurcation effects on the heat transfer and fluid flow are investigated and comparisons are made with the straight tube. Also, different bifurcation angles are simulated and the results are compared with the work of the other researchers.

Lattice Boltzmann Simulation of Flow and Heat Transfer Characteristics in a Symmetric Bifurcation

2005 ◽  
Author(s):  
K. Q. Xing ◽  
Y.-X. Tao
Keyword(s):  
Heat Transfer ◽  
Lattice Boltzmann ◽  
Passive Scalar ◽  
Heat Fluxes ◽  
Lattice Boltzmann Model ◽  
Lattice Boltzmann Simulation ◽  
Flux Boundary Conditions ◽  
Constant Wall Heat Flux ◽  
Boltzmann Method ◽  
Thermal Lattice Boltzmann

The lattice Boltzmann method (LBM) originates from the discrete kinetic theory and has been applied for simulation of various kinds of fluid flows under different conditions. In this paper, a passive-scalar-based thermal lattice Boltzmann model is employed to simulate the steady flow in a symmetric bifurcation channel under constant wall heat flux boundary conditions. The bifurcation effects on the heat transfer and fluid flow are thoroughly investigated under different Reynolds numbers, wall heat fluxes and bifurcation angles. The results are compared with the commercial software output. A useful discussion about how to transfer from lattice units to actual physical units is also presented.

scholarly journals Lattice Boltzmann simulation of melting phenomenon with natural convection from an eccentric annulus

2013 ◽  
Vol 17 (3) ◽  
pp. 877-890 ◽  
Author(s):  
Mahmoud Jourabian ◽  
Mousa Farhadi ◽  
Darzi Rabienataj ◽  
Abbas Abouei
Keyword(s):  
Natural Convection ◽  
Lattice Boltzmann ◽  
Outer Cylinder ◽  
Melting Process ◽  
Eccentric Annulus ◽  
Melting Phenomenon ◽  
Lattice Boltzmann Simulation ◽  
Double Population ◽  
Thermal Lattice Boltzmann ◽  
Change Problem

In the present study, a double-population thermal lattice Boltzmann was applied to solve phase change problem with natural convection in an eccentric annulus. The simulation of melting process from a concentrically and eccentrically placed inner hot cylinder inside an outer cold cylinder with Prandtl number of 6.2, Stefan number of 1 and Rayleigh number of 105 was carried out quantitatively. It was found that the position of the inner cylinder inside the outer cylinder significantly influence the flow patterns including the size and shape of two formed vortexes. It is also observed that the maximum of liquid fractions occurs where the inner cylinder is mounted at the bottom of outer cylinder.

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