Magnetohydrodynamic Free Convection Heat Transfer in a Square Enclosure heated from side and cooled from the ceiling

Author(s):  
Mostafa Mahmoodi ◽  
Zeynab Talea'pour
2015 ◽  
Vol 66 ◽  
pp. 34-43 ◽  
Author(s):  
Douglas Hector Fontes ◽  
Daniel Dall’Onder dos Santos ◽  
Elie Luis Martínez Padilla ◽  
Enio Pedone Bandarra Filho

2010 ◽  
Vol 133 (2) ◽  
Author(s):  
Mostafa Varmazyar ◽  
Majid Bazargan

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.


Author(s):  
Majid Bazargan ◽  
Mostafa Varmazyar

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.


Energies ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 559
Author(s):  
Janusz T. Cieśliński ◽  
Slawomir Smolen ◽  
Dorota Sawicka

The results of experimental investigation of free convection heat transfer in a rectangular container are presented. The ability of the commonly accepted correlation equations to reproduce present experimental data was tested as well. It was assumed that the examined geometry fulfils the requirement of no-interaction between heated cylinder and bounded surfaces. In order to check this assumption recently published correlation equations that jointly describe the dependence of the average Nusselt number on Rayleigh number and confinement ratios were examined. As a heat source served electrically heated horizontal tube immersed in an ambient fluid. Experiments were performed with pure ethylene glycol (EG), distilled water (W), and a mixture of EG and water at 50%/50% by volume. A set of empirical correlation equations for the prediction of Nu numbers for Rayleigh number range 3.6 × 104 < Ra < 9.2 × 105 or 3.6 × 105 < Raq < 14.8 × 106 and Pr number range 4.5 ≤ Pr ≤ 160 has been developed. The proposed correlation equations are based on two characteristic lengths, i.e., cylinder diameter and boundary layer length.


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