Modeling of Free Convection Heat Transfer to a Supercritical Fluid in a Square Enclosure by the Lattice Boltzmann Method

2010 ◽  
Vol 133 (2) ◽  
Author(s):  
Mostafa Varmazyar ◽  
Majid Bazargan
Keyword(s):  
Heat Transfer ◽  
Free Convection ◽  
Supercritical Fluid ◽  
Finite Volume ◽  
Lattice Boltzmann ◽  
Convection Heat Transfer ◽  
Convection Heat ◽  
Square Enclosure ◽  
Free Convection Heat ◽  
Boltzmann Method

During the last decade, a number of numerical computations based on the finite volume approach have been reported, studying various aspects of heat transfer near the critical point. In this paper, a lattice Boltzmann method (LBM) has been developed to simulate laminar free convection heat transfer to a supercritical fluid in a square enclosure. The LBM is an ideal mesoscopic approach to solve nonlinear macroscopic conservation equations due to its simplicity and capability of parallelization. The lattice Boltzmann equation (LBE) represents the minimal form of the Boltzmann kinetic equation. The LBE is a very elegant and simple equation, for a discrete density distribution function, and is the basis of the LBM. For the mass and momentum equations, a LBM is used while the heat equation is solved numerically by a finite volume scheme. In this study, interparticle forces are taken into account for nonideal gases in order to simulate the velocity profile more accurately. The laminar free convection cavity flow has been extensively used as a benchmark test to evaluate the accuracy of the numerical code. It is found that the numerical results of this study are in good agreement with the experimental and numerical results reported in the literature. The results of the LBM-FVM (finite volume method) combination are found to be in excellent agreement with the FVM-FVM combination for the Navier–Stokes and heat transfer equations.

Modeling of Free Convection Heat Transfer to a Supercritical Fluid in a Square Enclosure by the Lattice Boltzmann Method

2009 ◽  
Author(s):  
Majid Bazargan ◽  
Mostafa Varmazyar
Keyword(s):  
Heat Transfer ◽  
Free Convection ◽  
Lattice Boltzmann Method ◽  
Supercritical Fluid ◽  
Lattice Boltzmann ◽  
Convection Heat Transfer ◽  
Convection Heat ◽  
Square Enclosure ◽  
Free Convection Heat ◽  
Boltzmann Method

During the last decade a number of numerical computations based on the finite volume approach have been reported studying various aspects of heat transfer near the critical point. In this paper, a Lattice Boltzmann Method (LBM) has been developed to simulate laminar free convection heat transfer to a supercritical fluid in a square enclosure. The LBM is an ideal mesoscopic approach to solve nonlinear macroscopic conservation equations due to its simplicity and capability of parallelization. The Lattice Boltzmann Equation (LBE) represents the minimal form of the Boltzmann kinetic equation. The LBE is a very elegant and simple equation, for a discrete density distribution function and is the basis of the LBM. For the mass and momentum equations, an LBM is used while the heat equation is solved numerically by a finite volume scheme. In this study, inter-particle forces are taken into account for non-ideal gases in order to simulate the velocity profile more accurately. The laminar free convection cavity flow has been extensively used as a benchmark test to evaluate the accuracy of the numerical code. It is found that the numerical results of this study are in good agreement with the experimental and numerical results reported in the literature. The results of the LBM–FVM combination are found to be in excellent agreement with the FVM–FVM combination for the Navier-Stokes and heat transfer equations.

scholarly journals Comparison of the Finite Volume and Lattice Boltzmann Methods for Solving Natural Convection Heat Transfer Problems inside Cavities and Enclosures

2014 ◽  
Vol 2014 ◽  
pp. 1-15 ◽  
Author(s):  
M. Goodarzi ◽  
M. R. Safaei ◽  
A. Karimipour ◽  
K. Hooman ◽  
M. Dahari ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Natural Convection ◽  
Finite Volume Method ◽  
Finite Volume ◽  
Lattice Boltzmann ◽  
Convection Heat Transfer ◽  
Natural Convection Heat Transfer ◽  
Convection Heat ◽  
Square Enclosure ◽  
Volume Method

Different numerical methods have been implemented to simulate internal natural convection heat transfer and also to identify the most accurate and efficient one. A laterally heated square enclosure, filled with air, was studied. A FORTRAN code based on the lattice Boltzmann method (LBM) was developed for this purpose. The finite difference method was applied to discretize the LBM equations. Furthermore, for comparison purpose, the commercially available CFD package FLUENT, which uses finite volume Method (FVM), was also used to simulate the same problem. Different discretization schemes, being the first order upwind, second order upwind, power law, and QUICK, were used with the finite volume solver where the SIMPLE and SIMPLEC algorithms linked the velocity-pressure terms. The results were also compared with existing experimental and numerical data. It was observed that the finite volume method requires less CPU usage time and yields more accurate results compared to the LBM. It has been noted that the 1st order upwind/SIMPLEC combination converges comparatively quickly with a very high accuracy especially at the boundaries. Interestingly, all variants of FVM discretization/pressure-velocity linking methods lead to almost the same number of iterations to converge but higher-order schemes ask for longer iterations.

Dual-MRT lattice Boltzmann method combined with experimental measurements of nanofluid’s properties for analysis of fin-orientation effect on natural convection heat transfer

2020 ◽  
Vol 30 (12) ◽  
pp. 5017-5035
Author(s):  
Xiaodong Wang ◽  
David Ross
Keyword(s):  
Heat Transfer ◽  
Natural Convection ◽  
Free Convection ◽  
Lattice Boltzmann ◽  
Convection Heat Transfer ◽  
Experimental Measurements ◽  
Natural Convection Heat Transfer ◽  
Convection Heat ◽  
Content Type ◽  
Boltzmann Method

Purpose Natural convection heat transfer during free convection phenomenon in a cavity included with active fins and pipes is investigated. The influence of the orientation of fins on the heat transfer between heat source (i.e. hot fins) and heat sink (i.e. cold pipes) is investigated by using numerical and experimental techniques. Design/methodology/approach For the numerical simulations, the multiple relaxation time (MRT) thermal lattice Boltzmann method (LBM) is used. In this numerical approach, two separated distribution functions are used to solve the flow and temperature distributions within the computational domain. Furthermore, the local/volumetric second law analysis is used to show the impact of evaluated parameters on the heat transfer irreversibility. In addition, the dynamic viscosity and thermal conductivity of TiO2-water nanofluid are measured by using Brookfield viscometer and KD2 pro conductmeter, respectively. Findings The examined range of Rayleigh number is from 103 to 106, and the nanofluid samples are provided in 0, 20, 40, 60, 80 and 100 ppm. Originality/value The originality of this work is use of dual-MRT thermal LBM and experimental measurements of rheological/thermal properties of nanofluid for investigation of free convection problem for the considered application.

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